OKE ONEOK Inc

As filed with the Securities and Exchange Commission on December 9, 2024

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

__________________________________________

FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

__________________________________________

ONEOK, INC.

(Exact name of registrant as specified in its charter)

__________________________________________

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

__________________________________________

Lyndon C. Taylor
Executive Vice President, Chief Legal Officer and Assistant Secretary
ONEOK, Inc.
100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

(Name, address, including zip code, and telephone number, including area code, of agent for service)

__________________________________________

__________________________________________

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after the effectiveness of this registration statement and the satisfaction or waiver of all other conditions to the closing of the merger described herein.

If the securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box. ☐

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) ☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

The information in this proxy statement/prospectus is not complete and may be changed. A registration statement relating to the securities described in this proxy statement/prospectus has been filed with the U.S. Securities and Exchange Commission. We may not issue the securities described herein until the registration statement filed with the U.S. Securities and Exchange Commission is effective. This proxy statement/prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY — SUBJECT TO COMPLETION — DATED DECEMBER 9, 2024

MERGER PROPOSED — YOUR VOTE IS VERY IMPORTANT

Dear Unitholder of EnLink Midstream, LLC:

On November 24, 2024, EnLink Midstream, LLC (“EnLink”) and ONEOK, Inc. (“ONEOK”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Elk Merger Sub I, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub I”), Elk Merger Sub II, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub II”), and EnLink Midstream Manager, LLC, the managing member of EnLink (the “Manager”), pursuant to which (i) Merger Sub I will merge with and into EnLink (the “First Merger”), with EnLink as the surviving company and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the effective time of the Second Merger (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II (the “Second Merger” and, together with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK.

In the Mergers, the holders of common units representing limited liability company interests in EnLink (each such common unit, an “EnLink Unit,” and each such holder, an “EnLink unitholder”) will receive, for each EnLink Unit that they own as of immediately prior to the effective time of the First Merger (the “First Merger Effective Time”), 0.1412 shares of common stock of ONEOK, par value $0.01 per share (“ONEOK Common Stock”; such consideration, the “Merger Consideration” and such ratio, the “Exchange Ratio”). As of the effective time of the Mergers, the limited liability company interests in the Manager, and any EnLink Units that are owned immediately prior to the First Merger Effective Time by the Manager, ONEOK, Merger Sub I or Merger Sub II, will remain unchanged and outstanding until the effective time of the Second Merger and the Manager, as the holder of such managing member interests, will continue as the sole manager of EnLink. Prior to the First Merger Effective Time, each Series B Preferred Unit of EnLink Midstream Partners, LP (“EnLink Partners”) will be redeemed for cash or converted into EnLink Units pursuant to the terms of the EnLink Partners partnership agreement.

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each award of restricted incentive units of EnLink (each, an “EnLink RIU” and such award, an “EnLink RIU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each award of performance units of EnLink (each, an “EnLink PU” and such award, an “EnLink PU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each tranche of the EnLink PU Award as identified in the applicable award agreement (an “EnLink PU Tranche”) equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the transactions contemplated by the Purchase Agreement, dated as of August 28, 2024, by and among ONEOK, GIP III Stetson I, L.P., GIP III Stetson II, L.P. and Manager, acting solely in its individual capacity and not in its capacity as managing member of EnLink, taking into account any applicable proration provisions) multiplied

proxy statement/prospectus, has irrevocably agreed to vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The EnLink Special Meeting will be held virtually on [            ], 2025, at [            ], Central Time. EnLink unitholders of record as of [            ], 2024 are entitled to vote at the EnLink Special Meeting. The EnLink Conflicts Committee and the EnLink Board have each unanimously approved the Merger Agreement and recommend that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

If the Mergers are completed, at the First Merger Effective Time, each EnLink Unit issued and outstanding as of immediately prior to the First Merger Effective Time (except for any EnLink Units that are owned immediately prior to the First Merger Effective Time by EnLink as treasury units, if any, or by the Manager, ONEOK, Merger Sub I, or Merger Sub II) will convert automatically into the right to receive 0.1412 shares of ONEOK Common Stock, with cash paid in lieu of the issuance of fractional shares, if any. Although the number of shares of ONEOK Common Stock that EnLink unitholders will receive in exchange for their EnLink Units is fixed (subject to adjustments in accordance with the terms of the Merger Agreement), the market value of the Merger Consideration will fluctuate with the market price of ONEOK Common Stock and will not be known at the time EnLink unitholders vote to approve the Merger Agreement and the Mergers contemplated thereby. Based on the closing price of ONEOK Common Stock on the NYSE on November 22, 2024, the last trading day before the public announcement of the parties entering into the Merger Agreement, the Exchange Ratio represented approximately $16.53 in value for each EnLink Unit. Based on the closing price of ONEOK Common Stock on the NYSE on [            ], 2024, the last practicable trading day before the date of the accompanying proxy statement/prospectus, the Exchange Ratio represented approximately $[            ] in value for each EnLink Unit. Based on the estimated number of shares of ONEOK Common Stock and estimated number of EnLink Units, as well as the outstanding equity awards of the parties, that will be outstanding immediately prior to the consummation of the Mergers, we estimate that, upon consummation of the Mergers, current ONEOK shareholders will hold approximately [            ]%, and current EnLink unitholders will hold approximately [            ]%, of the issued and outstanding shares of ONEOK Common Stock (in each case based on fully diluted shares or units, as applicable, outstanding of each company). We urge you to obtain current market quotations for ONEOK Common Stock (trading symbol “OKE”) and EnLink Units (trading symbol “ENLC”).

The obligations of ONEOK and EnLink to complete the Mergers are subject to the satisfaction or waiver of a number of conditions set forth in the Merger Agreement, a copy of which is attached as Annex A to the accompanying proxy statement/prospectus. The accompanying proxy statement/prospectus describes the EnLink Special Meeting and the proposals to be considered thereat, the Mergers and the documents and agreements related to the Mergers. It also contains or references information about ONEOK and EnLink and certain related agreements and matters. Please carefully read the entire accompanying proxy statement/prospectus, including “Risk Factors” beginning on page 13, for a discussion of the risks relating to the proposed Mergers. You also can obtain information about ONEOK and EnLink from documents that each has filed with the U.S. Securities and Exchange Commission. Please see the section entitled “Where You Can Find More Information” beginning on page 115 of the accompanying proxy statement/prospectus for how you may obtain such information.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued in connection with the Mergers described in the accompanying proxy statement/prospectus or determined that the accompanying proxy statement/prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

The accompanying proxy statement/prospectus is dated [            ], 2024 and is first being mailed to EnLink unitholders on or about [            ], 2024.

NOTICE OF SPECIAL MEETING OF UNITHOLDERS
OF
Enlink midstream, llc
TO BE HELD ON [    ], 2025

Dear Unitholder of EnLink Midstream, LLC:

On [    ], 2025, EnLink Midstream, LLC (“EnLink”) will hold a special meeting of unitholders (the “EnLink Special Meeting”) virtually at [    ], on [    ], 2025, at [    ], Central Time. Only holders of common units representing limited liability company interests of EnLink (each such common unit, an “EnLink Unit,” and each such holder, an “EnLink unitholder”) of record as of [    ], 2024 (the “Record Date”) are entitled to receive this notice and to vote at the EnLink Special Meeting or any adjournment or postponement of that meeting. The EnLink Special Meeting has been called for the following purposes:

1.      To consider and vote upon a proposal to approve the Agreement and Plan of Merger, dated as of November 24, 2024 (the “Merger Agreement”), by and among EnLink, ONEOK, Inc. (“ONEOK”), Elk Merger Sub I, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub I”), Elk Merger Sub II, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub II”), and EnLink Midstream Manager, LLC, the managing member of EnLink (the “Manager”), as it may be amended from time to time, a copy of which is attached as Annex A to the proxy statement/prospectus, and the Mergers (as defined below) contemplated by the Merger Agreement (the “Merger Proposal”); and

2.      To consider and vote upon a proposal to approve, on a non-binding advisory basis, the compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers (the “Non-Binding Advisory Compensation Proposal”).

EnLink does not intend to transact any other business at the EnLink Special Meeting or any adjournment or postponement thereof, except such business as may properly be brought before the EnLink Special Meeting by or at the direction of the board of directors of the Manager (the “EnLink Board”) in accordance with the Third Amended and Restated Operating Agreement of EnLink, dated as of October 15, 2024, as amended or supplemented from time to time. These items of business are described in the enclosed proxy statement/prospectus. Please refer to the attached documents, including the Merger Agreement and all other annexes and any documents incorporated by reference, for further information with respect to the business to be transacted at the EnLink Special Meeting. You are encouraged to read the entire document carefully before voting. In particular, please see the sections entitled “The Mergers” beginning on page 35 for a description of the transactions contemplated by the Merger Agreement and “Risk Factors” beginning on page 13 for an explanation of the risks associated with the Mergers and the other transactions contemplated by the Merger Agreement.

Approval of the Merger Proposal by the affirmative vote of the holders of a majority of the outstanding EnLink Units entitled to vote thereon is required to complete the Mergers, as contemplated by the Merger Agreement. EnLink unitholders will also be asked to approve the Non-Binding Advisory Compensation Proposal.

The EnLink Board has designated the close of business on [    ], 2024 as the Record Date for the purpose of determining the EnLink unitholders who are entitled to receive notice of, and to vote at, the EnLink Special Meeting and any adjournment or postponement of the meeting, unless a new record date is fixed in connection with any adjournment or postponement of the meeting. Only holders of record of EnLink Units at the close of business on the Record Date are entitled to notice of, and to vote at, the EnLink Special Meeting and at any adjournment or postponement of the meeting. For additional information regarding the EnLink Special Meeting, see the section entitled “Special Meeting of EnLink Unitholders” beginning on page 27 of the proxy statement/prospectus accompanying this notice.

Pursuant to the Merger Agreement, (i) Merger Sub I will merge with and into EnLink (the “First Merger”), with EnLink as the surviving company and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the effective time of the Second Merger (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II (the “Second Merger” and, together with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK.

The conflicts committee (the “EnLink Conflicts Committee”) of the EnLink Board unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement (as defined below), were in the best interests of EnLink and the EnLink unitholders other than ONEOK, Manager and their respective affiliates (the “EnLink Unaffiliated Unitholders”), (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, and the execution, delivery, and performance of such agreements and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, and the execution, delivery, and performance of such agreements and the transactions contemplated thereby, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of such agreements and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement. The EnLink Conflicts Committee and the EnLink Board each recommend that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

Properly executed proxy cards with no instructions indicated on the proxy card will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal. The presence, in person or by proxy, of EnLink unitholders as of the Record Date representing a majority of outstanding EnLink Units is necessary to constitute a quorum for purposes of voting on the proposals during the EnLink Special Meeting. Abstention votes will count as present for purposes of establishing a quorum during the EnLink Special Meeting. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting. Even if you plan to attend the EnLink Special Meeting virtually, EnLink requests that you vote by Internet or telephone or complete, sign, date and return the enclosed proxy card in the accompanying envelope as promptly as possible to ensure that your EnLink Units will be represented and voted at the EnLink Special Meeting if you later decide not to or become unable to attend virtually.

Please vote as promptly as possible, whether or not you plan to attend the EnLink Special Meeting virtually. If your EnLink Units are held in the name of a broker, bank, or other nominee, please vote by following the instructions on the voting instruction form furnished by the broker, bank, or other nominee. If you hold your EnLink Units in your own name, submit a proxy to vote your EnLink Units as promptly as possible by (i) visiting the Internet site listed on the proxy card, (ii) calling the toll-free number listed on the proxy card or (iii) submitting your proxy card by mail by using the self-addressed, stamped envelope provided. Submitting a proxy will not prevent you from voting virtually, but it will help to secure a quorum and avoid added solicitation costs. Any eligible EnLink unitholder entitled to vote thereon and who is virtually present at the EnLink Special Meeting may vote, thereby revoking any previous proxy. In addition, a proxy may also be revoked in writing before the EnLink Special Meeting in the manner described in the accompanying proxy statement/prospectus.

If you have any questions concerning the Merger Proposal, the Non-Binding Advisory Compensation Proposal, the Mergers or the proxy statement/prospectus, would like additional copies or need help voting your EnLink Units, please contact EnLink’s proxy solicitor:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

Dallas, Texas
[    ], 2024

ABOUT THIS PROXY STATEMENT/PROSPECTUS; ADDITIONAL INFORMATION

This document, which forms part of a registration statement on Form S-4 filed with the U.S. Securities and Exchange Commission (the “SEC”) by ONEOK, constitutes a prospectus of ONEOK under Section 5 of the Securities Act of 1933, as amended (the “Securities Act”), with respect to the shares of ONEOK Common Stock to be issued to EnLink unitholders pursuant to the Merger Agreement. This document also constitutes a proxy statement of EnLink under Section 14(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). It also constitutes a notice of meeting with respect to the EnLink Special Meeting.

You should rely only on the information contained in or incorporated by reference into this proxy statement/prospectus. ONEOK and EnLink have not authorized anyone to provide you with information that is different from that contained in or incorporated by reference into this proxy statement/prospectus. This proxy statement/prospectus is dated [    ], 2024. The information contained in this proxy statement/prospectus is accurate only as of that date or, in the case of information in a document incorporated by reference, as of the date of such document, unless the information specifically indicates that another date applies. Neither the mailing of this proxy statement/prospectus to EnLink unitholders nor the issuance by ONEOK of shares of ONEOK Common Stock pursuant to the Merger Agreement will create any implication to the contrary.

This proxy statement/prospectus does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction. ONEOK has supplied all information contained in this proxy statement/prospectus relating to ONEOK, and EnLink has supplied all such information relating to EnLink. ONEOK and EnLink have both contributed to the information related to the Mergers contained in this proxy statement/prospectus.

Except as otherwise specifically noted, or the context otherwise requires, as used in this proxy statement/prospectus:

•        “Effective Time” means the effective time of the Second Merger and as set forth in the Merger Agreement.

•        “EnLink” refers to EnLink Midstream, LLC, a Delaware limited liability company;

•        “EnLink Board” refers to the board of directors of Manager;

•        “EnLink Conflicts Committee” refers to the conflicts committee of the EnLink Board;

•        “EnLink Special Meeting” refers to the special meeting of EnLink unitholders;

•        “EnLink Units” refers to the common units representing limited liability company interests of EnLink;

•        “EnLink unitholders” refers to the holders of EnLink Units;

•        “First Merger” refers to the merger, pursuant to the Merger Agreement, of Merger Sub I with and into EnLink, with EnLink as the surviving company;

•        “Manager” refers to EnLink Midstream Manager, LLC, a Delaware limited liability company and the managing member of EnLink;

•        “Merger Agreement” refers to the Agreement and Plan of Merger, dated as of November 24, 2024, by and among ONEOK, EnLink, Merger Sub I, Merger Sub II, and Manager, as it may be amended from time to time;

•        “Merger Consideration” refers to the 0.1412 shares of ONEOK Common Stock per outstanding EnLink Unit that will be issued to EnLink unitholders in connection with the Mergers;

•        “Merger Sub I” refers to Elk Merger Sub I, L.L.C., a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK;

•        “Merger Sub II” refers to Elk Merger Sub II, L.L.C., a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK;

•        “Merger Subs” refers to, collectively, Merger Sub I and Merger Sub II;

•        “Mergers” refers to, collectively, the First Merger and the Second Merger;

•        “ONEOK” refers to ONEOK, Inc., an Oklahoma corporation;

•        “ONEOK Board” refers to the board of directors of ONEOK;

•        “ONEOK Common Stock” refers to the common stock of ONEOK, par value $0.01 per share;

•        “Second Merger” refers to the merger, pursuant to the Merger Agreement and promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, of EnLink, as the surviving entity in the First Merger, with and into Merger Sub II, with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK; and

•        references to directors and executive officers of EnLink refer to the directors and executive officers of Manager, the managing member of EnLink.

As permitted under the rules of the SEC, this document incorporates by reference important business and financial information about ONEOK and EnLink from other documents filed with the SEC that are not included in or delivered with this document. Please read the section titled “Where You Can Find More Information.” You can obtain any of the documents incorporated by reference into this document from the SEC’s website at www.sec.gov. This information is also available to you without charge upon your request in writing or by telephone from ONEOK or EnLink at the following addresses and telephone numbers:

Please note that copies of the documents provided to you will not include exhibits, unless the exhibits are specifically incorporated by reference into the documents or this document.

To obtain timely delivery of these documents before the EnLink Special Meeting, EnLink unitholders must request the information no later than [    ], 2025 (which is five business days before the date of the EnLink Special Meeting).

You may also obtain certain of these documents at ONEOK’s website, www.oneok.com, and at EnLink’s website, www.enlink.com. Except as expressly provided herein, none of the information contained on or accessible through the websites of ONEOK or EnLink is incorporated by reference into this document.

In addition, if you have questions about the Mergers or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus or need to obtain letters of transmittal (which are being mailed to EnLink unitholders) or other information related to the proxy solicitation, contact: Innisfree M&A Incorporated, the proxy solicitor for EnLink, toll-free at (866) 239-1762 or, for brokers and banks, collect at (212) 750-5833. You will not be charged for any of these documents that you request.

TABLE OF CONTENTS

QUESTIONS AND ANSWERS ABOUT THE MERGERS AND THE ENLINK SPECIAL MEETING

The following questions and answers briefly address some commonly asked questions about the Mergers and the EnLink Special Meeting. You are urged to read the remainder of this document carefully because the information in this section may not provide all the information that might be important to you in determining how to vote. Additional important information is also contained in the annexes to, and the documents incorporated by reference in, this document.

Q:     Why am I receiving these materials?

A:     You are receiving this proxy statement/prospectus because ONEOK and EnLink have entered into the Merger Agreement, pursuant to which, on the terms and subject to the fulfillment or, to the extent permissible under applicable law, waiver of the conditions included in the Merger Agreement, (i) in the First Merger, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) in the Second Merger, promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK. As referred to in this proxy statement/prospectus, the “First Merger Effective Time” means the effective time of the First Merger and as set forth in the Merger Agreement. As referred to in this proxy statement/prospectus, the “Effective Time” means the effective time of the Second Merger and as set forth in the Merger Agreement. The Merger Agreement governs the terms of the Mergers and is attached to this proxy statement/prospectus as Annex A.

In order to complete the Mergers, among other things, EnLink unitholders must approve the Merger Agreement and the Mergers contemplated thereby in accordance with Delaware law.

This proxy statement/prospectus serves as both the proxy statement through which EnLink will solicit proxies to obtain the necessary unitholder approvals for the Mergers and the prospectus by which ONEOK will issue shares of ONEOK Common Stock as consideration in the Mergers. This proxy statement/prospectus, which you should carefully read in its entirety, contains important information about the EnLink Special Meeting, the Mergers and other matters.

Q:     What will happen in the Mergers?

A:     The Merger Agreement sets forth the terms and conditions of the proposed Mergers. Under the Merger Agreement, (i) in the First Merger, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) in the Second Merger, promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK.

The Merger Agreement is attached to this proxy statement/prospectus as Annex A. For additional information regarding the proposed Mergers, their effects and the other transactions contemplated by the Merger Agreement, please see the section entitled “The Mergers.”

Q:     When and where is the EnLink Special Meeting? How can I attend the EnLink Special Meeting?

A:     The EnLink Special Meeting will be held virtually at [    ], on [    ], 2025, at [    ], Central Time. Online access will begin at [    ], Central Time, and EnLink encourages its unitholders to access the meeting prior to the start time. The EnLink Special Meeting will be held in a virtual meeting format only, via live webcast, and there will not be a physical meeting location.

EnLink unitholders as of close of business on [    ], 2024 (the “Record Date”) may attend, vote and submit questions virtually at the EnLink Special Meeting by logging in at [    ]. To log in, EnLink unitholders (or their authorized representatives) will need the control number provided on their proxy card, voting instruction form or notice. If you are not an EnLink unitholder or do not have a control number, you may still access the meeting as a guest, but you will not be able to participate.

Even if you plan to attend the EnLink Special Meeting virtually, EnLink recommends that you submit a proxy with respect to your units in advance as described above so that your vote will be counted if you later decide not to or become unable to attend the EnLink Special Meeting.

Q:     Who is entitled to vote at the EnLink Special Meeting?

A:     The Record Date for the EnLink Special Meeting is [    ], 2024. All EnLink unitholders who held EnLink Units at the close of business on the Record Date are entitled to receive notice of, and to vote at, the EnLink Special Meeting. Each such EnLink unitholder is entitled to cast one vote on each matter properly brought before the EnLink Special Meeting for each EnLink Unit that such holder owned of record as of the Record Date. Attendance at the EnLink Special Meeting, which will be held virtually, is not required for an EnLink unitholder’s units to be voted. For additional information on how to submit a proxy for your EnLink Units without attending the EnLink Special Meeting, please see the section entitled “Special Meeting of EnLink Unitholders — Voting at the EnLink Special Meeting.”

Q:     What are EnLink unitholders being asked to vote on?

A:     The EnLink unitholders are being asked to consider and vote on proposals to (i) approve the Merger Agreement and the Mergers contemplated thereby (the “Merger Proposal”), pursuant to which EnLink unitholders will receive, for each EnLink Unit that they own as of immediately prior to the First Merger Effective Time (except for any EnLink Units that are owned immediately prior to the First Merger Effective Time by EnLink as treasury units, if any, or by the Manager, ONEOK, Merger Sub I, or Merger Sub II (collectively, the “Excluded Units”)), 0.1412 shares of ONEOK Common Stock, and (ii) approve, on a non-binding advisory basis, the compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers (the “Non-Binding Advisory Compensation Proposal”).

Q:     How important is my vote as an EnLink unitholder?

A:     Your vote is very important. The proposed Mergers between ONEOK and EnLink cannot be completed without the approval of the Merger Proposal by the affirmative vote of a majority of the outstanding EnLink Units entitled to vote at the EnLink Special Meeting. The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal. You are encouraged to submit a proxy as soon as possible. Approval of the Non-Binding Advisory Compensation Proposal is not a condition to the consummation of the Mergers.

Q:     What constitutes a quorum and what vote is required to approve each proposal at the EnLink Special Meeting?

A:     EnLink unitholders holding a majority of the outstanding EnLink Units entitled to vote at the EnLink Special Meeting must be represented at the EnLink Special Meeting in person or by proxy in order to constitute a quorum. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The Merger Proposal.    Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, an EnLink unitholder’s abstention from voting or the failure of an EnLink unitholder to vote (including the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee) will have the same effect as a vote “against” the Merger Proposal.

The Non-Binding Advisory Compensation Proposal.    Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, an EnLink unitholder’s abstention from voting or the failure of an EnLink unitholder to vote (including the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee) will

have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers.

Q:     Have any EnLink unitholders agreed to vote their units in favor of the Merger Proposal or the Non-Binding Advisory Compensation Proposal?

A:     Yes. At the close of business on [            ], 2024, the latest practicable date prior to the date of this proxy statement/prospectus, ONEOK beneficially owned and is entitled to vote approximately [            ] EnLink Units, representing approximately [      ]% of the EnLink Units outstanding on that date. Pursuant to the terms of a Support Agreement, dated as of November 24, 2024, by and between ONEOK and EnLink (the “Support Agreement”), ONEOK has irrevocably agreed to vote such units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. For additional information regarding the Support Agreement, please see the section entitled “The Mergers — Support Agreement.”

Q:     What will EnLink unitholders receive if the Mergers are completed?

A:     If the Mergers are completed, each eligible EnLink Unit outstanding at the First Merger Effective Time will automatically be converted into the right to receive 0.1412 duly authorized and validly issued shares of ONEOK Common Stock (such ratio, the “Exchange Ratio”). Each EnLink unitholder will receive cash in lieu of any fractional share of ONEOK Common Stock that such EnLink unitholder would otherwise be entitled to receive in the Mergers.

Because ONEOK will issue a fixed number of shares of ONEOK Common Stock in exchange for each EnLink Unit, the value of the Merger Consideration that EnLink unitholders will receive in the Mergers will depend on the market price of shares of ONEOK Common Stock at the First Merger Effective Time. The market price of shares of ONEOK Common Stock that EnLink unitholders receive at the First Merger Effective Time could be greater than, less than or the same as the market price of shares of ONEOK Common Stock on the date of this proxy statement/prospectus or at the time of the EnLink Special Meeting. Accordingly, you should obtain current market quotations for ONEOK Common Stock and EnLink Units before deciding how to vote with respect to the Merger Proposal. ONEOK Common Stock is traded on the New York Stock Exchange (“NYSE”) under the symbol “OKE.” EnLink Units are traded on the NYSE under the symbol “ENLC.”

For additional information regarding the Merger Consideration to be received by EnLink unitholders if the Mergers are completed, please see the section entitled “The Merger Agreement — Merger Consideration.”

Q:     What equity stake will EnLink unitholders hold in ONEOK immediately following the Mergers?

A:     Based on the number of issued and outstanding shares of ONEOK Common Stock and EnLink Units as of [            ], 2024, and the Exchange Ratio of 0.1412 shares of ONEOK Common Stock for each EnLink Unit, holders of EnLink Units as of immediately prior to the First Merger Effective Time would hold, in the aggregate, approximately [            ]% of the issued and outstanding shares of ONEOK Common Stock immediately following the First Merger Effective Time. The exact equity stake of EnLink unitholders in ONEOK immediately following the First Merger Effective Time will depend on the number of shares of ONEOK Common Stock and EnLink Units issued and outstanding immediately prior to the First Merger Effective Time.

For additional information regarding the equity stake of EnLink unitholders in ONEOK following the Mergers, please see the sections entitled “The Merger Agreement — Merger Consideration” and “The Merger Agreement — Exchange of Units.”

Q:     Will EnLink equity and other long-term incentive awards be affected by the Mergers?

A:     Upon the completion of the Mergers, outstanding EnLink equity awards will be affected as described below.

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each award of restricted incentive units of EnLink (each, an “EnLink RIU” and such award, an “EnLink RIU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into

a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each award of performance units of EnLink (each, an “EnLink PU” and such award, an “EnLink PU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each tranche of the EnLink PU Award as identified in the applicable award agreement (an “EnLink PU Tranche”) equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the GIP Interest Acquisition (as defined below), taking into account any applicable proration provisions) multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture, except any performance-based vesting condition will not apply) as were applicable to such EnLink PU Award immediately prior to the First Merger Effective Time. For purposes of determining the number of EnLink Units subject to each EnLink PU Tranche, the following shall apply:

•        for each EnLink PU Tranche that vests based on performance metrics tied to the relative total shareholder return of EnLink (each, an “EnLink PU TSR Tranche”) and each EnLink PU Tranche that vests based on performance metrics tied to the cash flow of EnLink (each, an “EnLink PU DCF Tranche”) for which the performance period has closed prior to the date on which the closing of the Mergers (the “closing”) actually occurs (such date, the “closing date”), the number of EnLink Units shall be determined based on the actual achievement of the performance criteria attained through the end of the performance period, as previously certified by the EnLink Board or a committee thereof or, if not yet certified, as determined by the EnLink Board in good faith in the ordinary course of business consistent with past practice;

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has commenced but not closed as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance; and

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has not yet commenced as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance.

For additional information regarding the EnLink equity and other long-term incentive awards, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Treatment of EnLink Equity Awards.”

Q:     How do the EnLink Conflicts Committee and the EnLink Board recommend that I vote at the EnLink Special Meeting?

A:     The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that you vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink Unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal. For additional information regarding the recommendation of the EnLink Conflicts Committee and the EnLink Board, please see the section entitled “The Mergers — Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers.”

Q:     How many votes do I have for the EnLink Special Meeting?

A:     Each EnLink unitholder is entitled to one vote for each EnLink Unit held of record as of the close of business on the Record Date for each proposal. As of the close of business on the Record Date, there were [    ] outstanding EnLink Units.

Q:     What happens if the Mergers are not completed?

A:     If the EnLink unitholders do not approve the Merger Proposal or if the Mergers are not completed for any other reason, EnLink unitholders will not receive any Merger Consideration for their EnLink Units in connection with the Mergers. Instead, ONEOK and EnLink will each remain independent public companies. The ONEOK Common Stock will continue to be listed and traded on the NYSE, and the EnLink Units will continue to be listed and traded on the NYSE. Additionally, if the Merger Proposal is not approved by EnLink unitholders or if the Mergers are not completed for any other reason, ONEOK will not issue shares of ONEOK Common Stock to EnLink unitholders. If the Merger Agreement is terminated under certain specified circumstances, EnLink may be required to pay ONEOK a termination fee of $143,978,000 or to reimburse ONEOK’s expenses up to $10.0 million, and ONEOK may be required to reimburse EnLink’s expenses up to $10.0 million. For additional information regarding termination fees, please see the section entitled “The Merger Agreement — Termination Fee.”

Q:     What happens if the Non-Binding Advisory Compensation Proposal is not approved by EnLink unitholders?

A:     This vote is advisory and non-binding, and the Mergers are not conditioned or dependent upon the approval of the Non-Binding Advisory Compensation Proposal by EnLink unitholders. However, EnLink and ONEOK value the opinions of EnLink unitholders, and ONEOK expects to consider the outcome of the vote, along with other relevant factors, when considering future executive compensation, assuming the Mergers are completed. Because the executive compensation to be paid in connection with the Mergers is based on the terms of the Merger Agreement as well as the contractual arrangements between Manager and its named executive officers, subject to the contractual conditions applicable thereto, such compensation will be payable, regardless of the outcome of this advisory vote if the Merger Proposal is approved. However, EnLink seeks the support of its unitholders and believes that unitholder support is appropriate because Manager has a comprehensive executive compensation program designed to link the compensation of its named executive officers with EnLink’s performance and the interests of EnLink unitholders.

Q:     What is a proxy?

A:     A unitholder’s legal designation of another person to vote shares or units of such unitholder’s units at a special or annual meeting is referred to as a proxy. The document used to designate a proxy to vote your units is called a proxy card.

Q:     How can I vote my EnLink Units and participate at the EnLink Special Meeting?

A:     If you are an EnLink unitholder of record as of the close of business on the Record Date, you may submit your proxy before the EnLink Special Meeting in one of the following ways:

•        Telephone-use the toll-free number shown on your proxy card;

•        Internet-visit the website shown on your proxy card to vote via the Internet; or

•        Mail-complete, sign, date and return the enclosed proxy card in the enclosed postage-paid envelope.

If you are an EnLink unitholder of record, you may also cast your vote virtually at the EnLink Special Meeting by following the instructions at [    ]. If you decide to attend the EnLink Special Meeting virtually and vote at the meeting, your vote will revoke any proxy previously submitted.

The EnLink Special Meeting will begin promptly at [    ], Central Time, on [    ], 2025. EnLink encourages its unitholders to access the meeting prior to the start time leaving ample time for check-in. Please follow the instructions as outlined in this proxy statement/prospectus.

Even if you plan to attend the EnLink Special Meeting virtually, EnLink recommends that you submit your proxy with respect to your EnLink Units in advance as described below so that your vote will be counted if you later decide not to or become unable to attend the EnLink Special Meeting.

Q:     How can I vote my EnLink Units without attending the EnLink Special Meeting?

A:     Whether you hold your EnLink Units directly as a unitholder of record of EnLink or beneficially in “street name,” you may direct your vote by proxy without attending the EnLink Special Meeting. You can submit your proxy by mail, over the Internet or by telephone by following the instructions provided in the enclosed proxy card. Please note that if you hold EnLink Units beneficially in “street name,” you should follow the voting instructions provided by your bank, broker or other nominee.

For additional information regarding voting procedures, please see the section entitled “EnLink Special Meeting.”

Q:     What is the difference between holding units as a unitholder of record and as a beneficial owner of units held in “street name?”

A:     If your units are held in “street name” in a stock brokerage account or by a bank or other nominee, you must provide the record holder of your units with instructions on how to vote your units. Please follow the voting instructions provided by your broker, bank or other nominee. Please note that you may not vote units held in street name by returning a proxy card directly to EnLink or by voting virtually at the EnLink Special Meeting, unless you provide a “legal proxy,” which you must obtain from your broker, bank or other nominee.

Q:     If my EnLink Units are held in “street name” by my bank, broker or other nominee, will my bank, broker or other nominee automatically vote those units for me?

A:     Under the rules of the NYSE, your bank, broker or other nominee will only be permitted to vote your EnLink Units on “non-routine” matters if you instruct your bank, broker or other nominee how to vote. All of the proposals scheduled for consideration at the EnLink Special Meeting are “non-routine” matters. As a result, if you fail to provide voting instructions to your broker, bank or other nominee, your units will not be counted as present at the EnLink Special Meeting for purposes of determining a quorum and will not be voted on any of the proposals. To make sure that your units are voted on each of the proposals, you should instruct your bank, broker or other nominee how you wish to vote your units in accordance with the procedures provided by your bank, broker or other nominee regarding the voting of your units.

The effect of an EnLink unitholder not instructing its, his or her bank, broker or other nominee how such unitholder wishes to vote its, his or her units will be the same as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

Q:     What should I do if I receive more than one set of voting materials for the EnLink Special Meeting?

A:     If you hold EnLink Units in “street name” and also directly in your name as a unitholder of record or otherwise, or if you hold EnLink Units in more than one brokerage account, you may receive more than one set of voting materials relating to the EnLink Special Meeting.

Record Holders.    For units held directly, please complete, sign, date and return each proxy card, or you may cast your vote by telephone or Internet as provided on each proxy card, or otherwise follow the voting instructions provided in this proxy statement/prospectus in order to ensure that all of your EnLink Units are voted.

“Street name” Holders.    For units held in “street name” through a bank, broker or other nominee, you should follow the procedures provided by your bank, broker or other nominee to vote your units.

Q:     If an EnLink unitholder gives a proxy, how are the EnLink Units voted?

A:     Regardless of the method you choose to vote, the individuals named on the enclosed proxy card will vote your EnLink Units in the way that you indicate. When completing the proxy card or the Internet or telephone processes, you may specify whether your EnLink Units should be voted for or against, or abstain from voting on, all, some or none of the specific items of business to come before the EnLink Special Meeting.

Q:     How will my EnLink Units be voted if I return a blank proxy?

A:     If you sign, date and return your proxy card and do not indicate how you want your EnLink Units to be voted, then your EnLink Units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Q:     Can I change my vote of EnLink Units after I have submitted my proxy?

A:     Any EnLink unitholder giving a proxy has the right to revoke it before the proxy is voted at the EnLink Special Meeting by:

•        subsequently submitting a new proxy, whether by submitting a new proxy card or by submitting a proxy via the Internet or telephone, that is received by the deadline specified on the accompanying proxy card;

•        giving written notice of your revocation to EnLink’s Secretary;

•        voting virtually at the EnLink Special Meeting; or

•        revoking your proxy and voting at the EnLink Special Meeting.

Your attendance at the EnLink Special Meeting will not revoke your proxy unless you give written notice of revocation to EnLink’s Secretary before your proxy is exercised or unless you vote your units in person at the EnLink Special Meeting.

Execution or revocation of a proxy will not in any way affect your right to attend the EnLink Special Meeting and vote. Written notices of revocation and other communications with respect to the revocation of proxies should be addressed to:

EnLink Midstream, LLC
Attn: Secretary
1722 Routh Street, Suite 1300
Dallas, Texas 75201
(214) 953-9500

For additional information regarding revoking your proxy prior to the EnLink Special Meeting, please see the section entitled “Special Meeting of EnLink Unitholders — Revocation of Proxies.”

Q:     If I hold my EnLink Units in “street name,” can I change my voting instructions after I have submitted voting instructions to my bank, broker or other nominee?

A:     If your EnLink Units are held in the name of a bank, broker or other nominee and you previously provided voting instructions to your bank, broker or other nominee, you should follow the instructions provided by your bank, broker or other nominee to revoke or change your voting instructions.

Q:     Where can I find the voting results of the EnLink Special Meeting?

A:     The preliminary voting results for the EnLink Special Meeting will be announced at the EnLink Special Meeting. In addition, within four business days of the EnLink Special Meeting, EnLink intends to file the final voting results of its meeting with the SEC on a Current Report on Form 8-K.

Q:     Do EnLink unitholders have appraisal rights or dissenters’ rights?

A:     No. Under the Delaware Limited Liability Company Act (the “DLLCA”), EnLink unitholders are not entitled to appraisal or dissenters’ rights in connection with the Mergers.

Q:     As an EnLink unitholder, are there any risks that I should consider in deciding whether to vote for the approval of the Merger Proposal?

A:     Yes. You should read and carefully consider the risk factors set forth in “Risk Factors.” You also should read and carefully consider the risk factors of ONEOK and EnLink contained in the reports of ONEOK and EnLink which are incorporated by reference into this proxy statement/prospectus.

Q:     Do any of the officers or directors of EnLink have interests in the Mergers that may differ from or be in addition to my interests as an EnLink unitholder?

A:     Yes. In considering the recommendation of the EnLink Board and the EnLink Conflicts Committee that EnLink unitholders vote to approve the Merger Proposal, EnLink unitholders should be aware that certain of EnLink’s directors and executive officers have interests in the Mergers that are different from, or in addition to, the interests of EnLink unitholders generally. The EnLink Board and the EnLink Conflicts Committee were aware of and considered these differing interests, to the extent such interests existed at the time, among other matters, in evaluating and negotiating the terms and conditions of the Merger Agreement and the Mergers and each unanimously recommended that the Merger Agreement be approved by EnLink unitholders. For additional information regarding the interests of EnLink’s directors and officers in the Mergers, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers.”

Q:     What happens if I sell my EnLink Units after the Record Date but before the EnLink Special Meeting?

A:     The Record Date is earlier than the date of the EnLink Special Meeting. If you transfer your EnLink Units after the Record Date but before the EnLink Special Meeting, you will, unless special arrangements are made, retain your right to vote at the EnLink Special Meeting.

Q:     Who will solicit and pay the cost of soliciting proxies in connection with the EnLink Special Meeting?

A:     The EnLink Board is soliciting your proxy in connection with the EnLink Special Meeting, and EnLink will bear the cost of soliciting such proxies, however ONEOK and EnLink will each bear and pay one half of the expenses incurred in connection with the filing, printing and mailing this proxy statement/prospectus. EnLink has retained Innisfree M&A Incorporated as proxy solicitor to assist with the solicitation of proxies in connection with the EnLink Special Meeting. Solicitation initially will be made by mail. Forms of proxies and proxy materials may also be distributed through banks, brokers and other nominees to the beneficial owners of EnLink Units, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses. Proxies may also be solicited in person or by telephone, facsimile, electronic mail, or other electronic medium by certain of EnLink’s directors, officers and employees, as applicable, without additional compensation.

EnLink also may be required to reimburse banks, brokers and other custodians, nominees and fiduciaries or their respective agents for their expenses in forwarding proxy materials to beneficial owners of EnLink Units. EnLink’s directors, officers and employees also may solicit proxies by telephone, by electronic means or in person. They will not be paid any additional amounts for soliciting proxies.

Q:     Will ONEOK hold a special meeting of shareholders to approve the Mergers?

A:     No. No action by any ONEOK shareholder is required under applicable law or otherwise to adopt the Merger Agreement or issue the Merger Consideration. ONEOK will not solicit the vote or call a special meeting of ONEOK shareholders for the adoption of the Merger Agreement or issuance of the Merger Consideration. ONEOK shareholders are not being asked for a proxy and ONEOK shareholders are requested not to send ONEOK a proxy.

Q:     What are the expected U.S. federal income tax consequences of the Mergers to EnLink’s U.S. unitholders?

A:     The parties intend for the Mergers, taken together, to be treated as a tax-free reorganization under Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Code”). ONEOK and EnLink intend to report the Mergers, taken together, consistent with such treatment. Assuming the Mergers are so treated, a U.S. holder (as defined in the section entitled “Material U.S. Federal Income Tax Consequences”) generally will not recognize any gain or loss for U.S. federal income tax purposes upon the exchange of EnLink Units for shares of ONEOK Common Stock pursuant to the First Merger, except with respect to any cash received in lieu of fractional shares of ONEOK Common Stock.

It is a condition to EnLink’s and ONEOK’s obligations to complete the Mergers that EnLink receive an opinion from Baker Botts L.L.P., counsel to EnLink, or another nationally recognized tax counsel reasonably acceptable to EnLink and ONEOK (or if any such counsel is unable to deliver such opinion, Kirkland & Ellis LLP, counsel to ONEOK) that the Mergers, taken together, should qualify as a “reorganization” within the

meaning of Section 368(a) of the Code. However, none of the parties to the Merger Agreement have sought or intend to seek any ruling from the Internal Revenue Service (the “IRS”) regarding the qualification of the Mergers, taken together, as a reorganization within the meaning of Section 368(a) of the Code, and there can be no assurances that the IRS will agree with the opinion from counsel.

For additional information regarding the U.S. federal income tax consequences of the Mergers, please see the section entitled “Material U.S. Federal Income Tax Consequences.” Each EnLink unitholder is strongly urged to consult with a tax advisor to determine the particular U.S. federal, state or local or non-U.S. income or other tax consequences of the Mergers.

Q:     What are the expected U.S. federal income tax consequences for EnLink’s U.S. unitholders of the ownership of shares of ONEOK Common Stock after the Mergers are completed?

A:     ONEOK is classified as a corporation for U.S. federal income tax purposes and is subject to U.S. federal income tax on its taxable income. A distribution of cash by ONEOK to a shareholder that is a U.S. holder will generally be included in such U.S. holder’s income as dividend income to the extent of ONEOK’s current or accumulated “earnings and profits” as determined under U.S. federal income tax principles. Distributions of cash in excess of ONEOK’s current and accumulated earnings and profits will be treated as a non-taxable return of capital reducing a U.S. holder’s adjusted tax basis in such U.S. holder’s shares of ONEOK Common Stock and, to the extent the distribution exceeds such U.S. holder’s adjusted tax basis, as capital gain from the sale or exchange of such shares of ONEOK Common Stock.

Upon the sale, exchange, certain redemptions or other taxable dispositions of shares of ONEOK Common Stock received in the Mergers, a U.S. holder will generally recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of any other property received upon such taxable disposition of shares of ONEOK Common Stock and (ii) the U.S. holder’s adjusted tax basis in such shares of ONEOK Common Stock.

For additional information regarding the U.S. federal income tax consequences of owning and disposing of ONEOK Common Stock received in the Mergers, see the section entitled “Material U.S. Federal Income Tax Consequences.”

Q:     When are the Mergers expected to be completed?

A:     Subject to the satisfaction or, to the extent permissible under applicable law, waiver of the closing conditions described under “The Merger Agreement — Conditions to the Completion of the Mergers,” including the approval of the Merger Proposal, the Mergers are expected to close in the first quarter of 2025. However, neither ONEOK nor EnLink can predict the actual date on which the Mergers will be completed, or if the Mergers will be completed at all, because completion of the Mergers are subject to conditions and factors outside the control of either company. ONEOK and EnLink hope to complete the Mergers as soon as reasonably practicable. In addition, if the Mergers are not completed by May 23, 2025, either ONEOK or EnLink may choose not to proceed with the Mergers by terminating the Merger Agreement.

Q:     What are the conditions to completion of the Mergers?

A:     The Mergers are subject to a number of conditions to closing as specified in the Merger Agreement. These closing conditions include, among others, (i) the approval of the Merger Proposal by the EnLink unitholders; (ii) no applicable law, injunction, judgment or ruling enacted, promulgated, issued, entered, amended or enforced by any governmental authority shall be in effect enjoining, restraining, preventing or prohibiting consummation of the transactions contemplated by the Merger Agreement or making the consummation of the transactions contemplated by the Merger Agreement illegal; (iii) the registration statement on Form S-4, of which this proxy statement/prospectus forms a part, has become effective under the Securities Act and no stop order suspending the effectiveness of the registration statement has been issued and no proceedings for that purpose have been initiated or threatened by the SEC; (iv) the shares of ONEOK Common Stock deliverable to the EnLink unitholders as contemplated by the Merger Agreement have been approved for listing on the NYSE, subject to official notice of issuance; and (v) the receipt by EnLink, on the closing date, but before the First Merger Effective Time, of an opinion from nationally recognized tax counsel concluding that, on the basis of facts, representations and assumptions set forth or referred to in such opinion, for U.S. federal

income tax purposes, the Mergers, taken together, should qualify as a “reorganization” within the meaning of Section 368(a) of the Code. For additional information regarding the conditions to completion of the Mergers, please see the section entitled “The Merger Agreement — Conditions to the Completion of the Mergers.”

Q:     How will I receive the Merger Consideration to which I am entitled?

A:     If you hold your EnLink Units through The Depository Trust Company (“DTC”), you will not be required to take any specific actions to exchange your EnLink Units for shares of ONEOK Common Stock. After the completion of the Mergers, EnLink Units held through DTC in book-entry form will be automatically exchanged for shares of ONEOK Common Stock in book-entry form and an exchange agent (the “Exchange Agent”) selected by the parties will deliver to you a check in the aggregate amount of cash to be paid in lieu of any fractional share of ONEOK Common Stock to which you would otherwise be entitled immediately prior to the First Merger Effective Time. If you hold your EnLink Units in certificated form, or in book-entry form but not through DTC, after receiving the proper documentation from you, following the First Merger Effective Time, the Exchange Agent will deliver to you the ONEOK Common Stock and a check in the aggregate amount of cash to be paid in lieu of any fractional share of ONEOK Common Stock to which you would otherwise be entitled immediately prior to the First Merger Effective Time. For additional information, please see the section entitled “The Merger Agreement — Exchange of Units.”

Q:     What should I do now?

A:     You should read this proxy statement/prospectus carefully and in its entirety, including the annexes, and return your completed, signed and dated proxy card by mail in the enclosed postage-paid envelope, or you may submit your voting instructions by telephone or over the Internet as soon as possible so that your EnLink Units will be voted in accordance with your instructions.

Q:     Whom do I call if I have questions about the EnLink Special Meeting or the Mergers?

A:     If you are an EnLink unitholder and have questions about the EnLink Special Meeting or the Mergers, or desire additional copies of this proxy statement/prospectus or additional proxy cards, you may contact:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

RISK FACTORS

In deciding how to vote, EnLink unitholders should carefully consider the following risk factors, all of the information contained in or incorporated by reference herein, including but not limited to, the matters addressed in the section titled “Cautionary Statement Regarding Forward-Looking Statements” and the risks associated with each of the businesses of ONEOK and EnLink included in their respective Annual Reports on Form 10-K for the year ended December 31, 2023, as updated by subsequent Quarterly Reports on Form 10-Q, all of which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. Realization of any of the risks described below, any of the events described under “Cautionary Statement Regarding Forward-Looking Statements” or any of the risks or events described in the documents incorporated by reference could have a material adverse effect on ONEOK’s or EnLink’s business, financial condition, cash flows and results of operations and could result in a decline in the trading prices of their respective common stock or common units.

Risks Factors Related to the Mergers

Because the market price of ONEOK Common Stock will fluctuate prior to the consummation of the Mergers, EnLink unitholders cannot be sure of the market value of ONEOK Common Stock that they will receive in the Mergers. In addition, because the Exchange Ratio is fixed, the number of shares of ONEOK Common Stock to be received by EnLink unitholders in connection with the Mergers will not change between the date of this proxy statement/prospectus and the time the Mergers are completed to reflect changes in the trading prices of ONEOK Common Stock or EnLink Units.

At the time the Mergers are completed, EnLink unitholders will receive, for each EnLink Unit they own as of immediately prior to the First Merger Effective Time, 0.1412 shares of ONEOK Common Stock. The Exchange Ratio is fixed (subject to adjustments in accordance with the terms of the Merger Agreement), which means that it will not change between the date of this proxy statement/prospectus and the closing date, regardless of whether the market price of either ONEOK Common Stock or EnLink Units changes. Therefore, the value of the Merger Consideration will depend on the market price of ONEOK Common Stock at the First Merger Effective Time. The respective market prices of both ONEOK Common Stock and EnLink Units have fluctuated since the date of the announcement of the parties’ entry into the Merger Agreement and will continue to fluctuate from the date of this proxy statement/prospectus to the date of the EnLink Special Meeting, the closing date and thereafter. As of November 22, 2024, the last trading day prior to the announcement of the parties’ entry into the Merger Agreement, the closing price of ONEOK Common Stock was $117.05 and the market price of EnLink Units was $15.75. The market price of ONEOK Common Stock, when received by EnLink unitholders after the Mergers are completed, could be greater than, less than or the same as the market price of ONEOK Common Stock on the date of this proxy statement/prospectus or at the time of the EnLink Special Meeting. Accordingly, you should obtain current stock and unit price quotations, respectively, for ONEOK Common Stock and EnLink Units before deciding how to vote or abstain from voting on any of the proposals described in this proxy statement/prospectus.

Completion of the Mergers is subject to a number of conditions, including certain conditions that may not be satisfied or completed on a timely basis or at all.

Completion of the Mergers is subject to a number of conditions, which may be beyond the parties’ control and may prevent, delay or otherwise materially adversely affect the completion of the Mergers. These conditions include, among other things, EnLink unitholder approval of the Merger Agreement and the Mergers contemplated thereby. ONEOK and EnLink cannot predict with certainty whether and when any of these conditions will be satisfied. Any delay in completing the Mergers could cause ONEOK not to realize, or delay the realization, of some or all of the benefits that the companies expect to achieve from the Mergers. In such context, the date on which EnLink’s unitholders will receive the Merger Consideration is also uncertain. For additional information regarding the conditions to completion of the Mergers, please see the section entitled “The Merger Agreement — Conditions to the Completion of the Mergers.”

The Merger Agreement limits EnLink’s ability to pursue alternatives to the Mergers, which may discourage other companies from making a favorable alternative transaction proposal and, in specified circumstances, could require EnLink to pay ONEOK a termination fee.

The EnLink Board, based in part on the EnLink Conflicts Committee’s recommendation, has recommended that the EnLink unitholders vote in favor of the Merger Agreement and the Mergers. Under the Merger Agreement, if the EnLink Board or the EnLink Conflicts Committee, withdraws, modifies or qualifies, or proposes publicly to withdraw, modify or qualify its recommendation with respect to the Merger Proposal, unless the Merger Agreement has been terminated in accordance with its terms, EnLink will still be required to submit the Merger Proposal to a vote at the EnLink Special Meeting. For more information, please see the section entitled “The Merger Agreement — No Change of Recommendation by EnLink.” The Merger Agreement further provides that, if ONEOK terminates the Merger Agreement in response to an adverse recommendation change by the EnLink Conflicts Committee, EnLink will be required to pay ONEOK a termination payment of $143,978,000. In the event of termination of the Merger Agreement by ONEOK due to an uncured breach by EnLink or Manager, EnLink has agreed to reimburse ONEOK for all of its reasonable documented out-of-pocket expenses in connection with the Mergers, up to $10.0 million. In the event of termination of the Merger Agreement by EnLink due to an uncured breach by ONEOK or the Merger Subs, ONEOK has agreed to reimburse EnLink for all of its reasonable documented out-of-pocket expenses in connection with the Mergers, up to $10.0 million. Pease see the section entitled “The Merger Agreement — Termination Fee” for additional details.

These provisions regarding an EnLink adverse recommendation change could discourage a potential third-party acquirer or other strategic transaction partner that might have an interest in EnLink from considering or pursuing an alternative transaction with EnLink. These provisions might also result in a potential third-party acquirer or other strategic transaction partner proposing to pay a lower price than it might otherwise have proposed to pay because of the added expense of the termination fee that may become payable in certain circumstances.

ONEOK or EnLink may waive or modify the Merger Agreement, including one or more of the closing conditions, without re-soliciting unitholder approval or without consent of the ONEOK shareholders.

ONEOK or EnLink may determine to waive, in whole or part, one or more of the conditions to closing the Mergers prior to ONEOK or EnLink, as the case may be, being obligated to consummate the Mergers. Each of ONEOK and EnLink currently expects to evaluate the materiality of any waiver and its effect on its respective shareholders or unitholders in light of the facts and circumstances at the time, to determine whether any amendment of this proxy statement/prospectus or any re-solicitation of proxies of the EnLink unitholders is required in light of such waiver. Any determination whether to waive any condition to the Mergers or to re-solicit EnLink unitholder approval or amending or supplementing this proxy statement/prospectus as a result of a waiver will be made by ONEOK or EnLink at the time of such waiver based on the facts and circumstances as they exist at that time. Additionally, prior to the consummation of the Mergers, the parties to the Merger Agreement or other related transaction document may agree to modify or waive the terms or conditions of such documents without consent from the EnLink unitholders or the ONEOK shareholders.

The market price for ONEOK Common Stock following the closing may be affected by factors different from those that historically have affected or currently affect ONEOK Common Stock and EnLink Units.

Upon completion of the Mergers, EnLink unitholders who receive ONEOK Common Stock will become shareholders of ONEOK. ONEOK’s financial position may differ from its financial position before the completion of the Mergers, and the results of operations of ONEOK following the Mergers may be affected by some factors that are different from those currently affecting the results of operations of ONEOK and those currently affecting the results of operations of EnLink. Accordingly, the market price and performance of ONEOK Common Stock is likely to be different from the performance of EnLink Units, or ONEOK Common Stock in the absence of the Mergers. In addition, general fluctuations in stock markets could have a material adverse effect on the market for, or liquidity of, ONEOK Common Stock, regardless of ONEOK’s actual operating performance. For a discussion of the businesses of ONEOK and EnLink, and important factors to consider in connection with those businesses, see the documents attached hereto or incorporated by reference and referred to in “Where You Can Find More Information.”

Following the Mergers, current ONEOK shareholders and current EnLink unitholders will have reduced ownership and voting interest in ONEOK and will exercise less influence over ONEOK’s management.

As of the date of this proxy statement/prospectus, based on the Exchange Ratio, the number of outstanding EnLink Units and the number of outstanding shares of ONEOK Common Stock, it is expected that immediately following the First Merger Effective Time, current EnLink unitholders would own approximately [            ]% of the issued and outstanding shares of ONEOK Common Stock and current ONEOK shareholders would own approximately [            ]% of the issued and outstanding shares of ONEOK Common Stock, in each case on a fully diluted basis. As a result, ONEOK’s current shareholders and EnLink’s current unitholders will have less influence on the policies of ONEOK following the Mergers than they currently have on the policies of ONEOK and EnLink, respectively.

ONEOK Common Stock to be received by EnLink unitholders as a result of the Mergers will have different rights from EnLink Units.

Following completion of the Mergers, EnLink unitholders will no longer hold EnLink Units but will instead be shareholders of ONEOK. There are important differences between the rights of EnLink unitholders and the rights of ONEOK shareholders. For a discussion of the different rights associated with EnLink Units and ONEOK Common Stock, please see the section entitled “Comparison of Rights of EnLink Unitholders and ONEOK Shareholders.”

Completion of the Mergers may trigger change in control or other provisions in certain agreements to which EnLink or any of its subsidiaries or joint ventures is a party.

The completion of the Mergers may trigger change in control or other provisions in certain agreements to which EnLink or any of its subsidiaries or joint ventures is a party. If EnLink is unable to negotiate waivers of those provisions, the counterparties may exercise their rights and remedies under such agreements, potentially terminate such agreements, or seek monetary damages. Even if EnLink is able to negotiate waivers, the counterparties may require a fee for such waivers or seek to renegotiate such agreements on terms less favorable to EnLink or the applicable subsidiary or joint venture. Further, it may not be practicable to obtain waivers for certain change of control provisions and the conditions to such provisions may be subject to factors beyond ONEOK’s control. For example, the Mergers will constitute a change of control under the indentures governing EnLink’s 5.625% Senior Notes due 2028 and 6.500% Senior Notes due 2030 and, if such change of control were to be accompanied by certain ratings events, EnLink would be required to offer to repurchase such notes at a price set forth in the applicable indenture.

ONEOK and EnLink are expected to incur significant transaction costs in connection with the Mergers, which may be in excess of those anticipated by them.

ONEOK and EnLink have incurred and are expected to continue to incur a number of non-recurring costs associated with negotiating and completing the Mergers, combining the operations of the two companies and achieving desired synergies. These costs have been, and will continue to be, substantial and, in many cases, will be borne by ONEOK and EnLink whether or not the Mergers are completed. A substantial majority of non-recurring expenses will consist of transaction costs and include, among others, fees paid to financial, legal, accounting and other advisors, employee retention, severance and benefit costs, and filing fees. ONEOK will also incur costs related to formulating and implementing integration plans, including facilities and systems consolidation costs and other employment-related costs. ONEOK and EnLink will continue to assess the magnitude of these costs, and additional unanticipated costs may be incurred in connection with the Mergers and the integration of the two companies’ businesses. While ONEOK and EnLink have assumed that a certain level of expenses would be incurred, there are many factors beyond their control that could affect the total amount or the timing of the expenses. The elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses, may not offset integration-related costs and achieve a net benefit in the near term, or at all. The costs described above and any unanticipated costs and expenses, many of which will be borne by ONEOK or EnLink even if the Mergers are not completed, could have an adverse effect on ONEOK’s or EnLink’s financial condition and operating results.

If the Merger Agreement is terminated, under certain circumstances, EnLink may be obligated to pay a termination fee to ONEOK. This fee could require EnLink to seek loans or use its available cash that would have otherwise been available for operations, dividends or other general corporate purposes.

Upon termination of the Merger Agreement under certain circumstances, EnLink may be required to pay ONEOK a termination fee equal to $143,978,000 or to reimburse ONEOK’s expenses up to $10.0 million, and ONEOK may be required to reimburse EnLink’s expenses up to $10.0 million. If the Merger Agreement is terminated, the termination fee or reimbursement of expenses required to be paid, if any, by EnLink under the Merger Agreement may require EnLink to seek loans or borrow amounts to enable it to pay the fee to ONEOK. Payment of these amounts would reduce the cash EnLink has available for operations, distributions or other general corporate purposes. Please see the sections entitled “The Merger Agreement — Payment of Expenses” and “The Merger Agreement — Termination Fee.”

ONEOK may be unable to integrate the businesses of ONEOK and EnLink successfully or realize the anticipated benefits of the Mergers, which may adversely affect the value of the ONEOK Common Stock that EnLink unitholders would receive in the Mergers.

ONEOK’s ability to achieve the anticipated benefits of the Mergers will depend in part upon whether ONEOK can integrate EnLink’s business into its existing business in an efficient and effective manner. ONEOK may not be able to accomplish the integration process successfully. Potential difficulties that may be encountered as part of the integration process include the following:

•        the inability to successfully combine EnLink’s business into ONEOK’s existing business in a manner that permits it to achieve, on a timely basis, or at all, the enhanced revenue opportunities and cost savings and other benefits anticipated to result from the Mergers;

•        complexities associated with managing the combined business, including difficulty addressing possible differences in operational philosophies and the challenge of integrating complex systems, technology, networks and other assets of each of the companies in a seamless manner that minimizes any adverse impact on customers, suppliers, employees and other constituencies;

•        the assumption of contractual obligations with less favorable or more restrictive terms; and

•        potential unknown liabilities and unforeseen increased expenses or delays associated with the Mergers.

In addition, ONEOK and EnLink have operated and, until the completion of the Mergers, will continue to operate, independently. It is possible that the integration process could result in the disruption of, or the loss of momentum in, each company’s ongoing businesses or inconsistencies in standards, controls, procedures and policies.

Any of these issues could adversely affect each company’s ability to maintain relationships with customers, suppliers, employees and other constituencies or achieve the anticipated benefits of the Mergers or could reduce each company’s earnings or otherwise adversely affect ONEOK’s business and financial results following the Mergers, including the value of the ONEOK Common Stock that EnLink unitholders will receive as Merger Consideration.

The Merger Agreement subjects ONEOK and EnLink to restrictions on their respective business activities prior to the First Merger Effective Time.

The Merger Agreement subjects ONEOK and EnLink to restrictions on their respective business activities prior to the First Merger Effective Time. The Merger Agreement obligates EnLink to conduct its business (i) in the ordinary course of business consistent with past practice and (ii) in compliance with the EnLink Midstream Interim Period Restricted Actions, dated as of October 15, 2024 (as may be amended or supplemented, or as any actions thereunder may be waived or approved by the applicable representative of ONEOK, from time to time, the “EnLink Midstream Interim Period Restricted Actions”). The Merger Agreement restricts EnLink’s ability to (i) declare additional dividends (subject to certain exceptions), (ii) adopt a plan of liquidation, dissolution or restructuring, (iii) fail to consistently maintain material rights-of-way and real property, (iv) split or otherwise recapitalize EnLink Units or effect any other similar transaction, or (v) agree, in writing or otherwise, to take any of the foregoing actions or any action that would reasonably be expected to prevent or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers. The EnLink Midstream Interim Period Restricted Actions restricts EnLink’s ability to take certain actions, including, among other things, (i) make capital expenditures,

(ii) create or incur indebtedness, (iii) merge or consolidate with other businesses, and (iv) enter into or amend rights under material contracts. These restrictions could prevent EnLink from pursuing certain business opportunities that arise prior to the First Merger Effective Time and are outside the ordinary course of business. The Merger Agreement also restricts ONEOK’s ability to (i) amend its organizational documents in a way that would prevent the consummation of the Mergers, (ii) declare additional dividends (subject to certain exceptions), (iii) split or otherwise recapitalize ONEOK Common Stock or effect any other similar transaction, (iv) adopt a plan of liquidation, dissolution or restructuring, (v) directly or indirectly purchase or acquire any additional EnLink Units, or (vi) agree, in writing or otherwise, to take any of the foregoing actions or any action that would reasonably be expected to prevent or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers. Please see the section entitled “The Merger Agreement — Covenants — Conduct of Business Pending the Mergers” for additional details.

Uncertainties associated with the Mergers may cause a loss of management personnel and other key employees of ONEOK and EnLink, which could adversely affect the future business and operations of ONEOK following the Mergers.

ONEOK and EnLink are dependent on the experience and industry knowledge of their respective officers and other key employees to execute their business plans. ONEOK’s success after the Mergers will depend in part upon its ability to retain key management personnel and other key employees of both ONEOK and EnLink. Current and prospective employees of ONEOK and EnLink may experience uncertainty about their roles within ONEOK following the Mergers or other concerns regarding the timing and completion of the Mergers or the operations of ONEOK following the Mergers, any of which may have an adverse effect on the ability of ONEOK and EnLink to retain or attract key management and other key personnel. If ONEOK and EnLink are unable to retain personnel, including key management, who are critical to the future operations of the companies, ONEOK and EnLink could face disruptions in their operations, loss of existing customers, loss of key information, expertise or know-how and unanticipated additional recruitment and training costs. In addition, the loss of key personnel could diminish the anticipated benefits of the Mergers. No assurance can be given that ONEOK, following the Mergers, will be able to retain or attract key management personnel and other key employees to the same extent that ONEOK and EnLink have previously been able to retain or attract their own employees.

The Mergers may not be completed and the Merger Agreement may be terminated in accordance with its terms. Failure to complete the Mergers could negatively impact the price of ONEOK Common Stock and EnLink Units and have a material adverse effect on their results of operations, cash flows and financial position.

ONEOK or EnLink may elect to terminate the Merger Agreement in accordance with its terms in certain circumstances, as further detailed in the section entitled “The Merger Agreement — Termination of the Merger Agreement.” If the Mergers are not completed for any reason, including as a result of the EnLink unitholders’ failure to approve the Merger Proposal, the ongoing businesses of ONEOK and EnLink may be materially adversely affected and, without realizing any of the benefits of having completed the Mergers, ONEOK and EnLink would be subject to a number of risks, including the following:

•        ONEOK and EnLink may experience negative reactions from the financial markets, including negative impacts on their respective stock and unit prices;

•        ONEOK and EnLink and their respective subsidiaries may experience negative reactions from their respective customers, suppliers, vendors, landlords, joint venture partners and other business partners;

•        ONEOK and EnLink will still be required to pay certain significant costs relating to the Mergers, such as legal, accounting, financial advisor and printing fees;

•        matters relating to the Mergers (including integration planning) require substantial commitments of time and resources by each company’s management, which may have resulted in the distraction of each company’s management from ongoing business operations and pursuing other opportunities that could have been beneficial to the companies; and

•        litigation related to any failure to complete the Mergers or related to any enforcement proceeding commenced against ONEOK or EnLink to perform their respective obligations pursuant to the Merger Agreement.

If the Mergers are not completed, the risks described above may materialize and they may have a material adverse effect on ONEOK’s or EnLink’s results of operations, cash flows, financial position and stock prices. In addition to the above risks, if the Merger Agreement is terminated or the Mergers are otherwise not completed for any reason, there can be no assurances that either ONEOK or EnLink will be able to find a party willing to enter into an alternative transaction as attractive as the Mergers.

EnLink’s directors and executive officers have interests in the Mergers that may be different from, or in addition to, the interests of the EnLink unitholders generally.

In considering the recommendations of the EnLink Conflicts Committee and the EnLink Board that EnLink unitholders vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, EnLink unitholders should be aware of and take into account the fact that, aside from their interests as EnLink unitholders, certain of EnLink’s directors and executive officers have interests in the Mergers that may be different from, or in addition to, the interests of EnLink unitholders generally. These interests include, among others, rights to continuing indemnification and directors’ and officers’ liability insurance. For a more detailed description of these interests, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers.” The EnLink Conflicts Committee and the EnLink Board were aware of and considered these potential interests, among other matters, in evaluating and negotiating the Merger Agreement and the transactions contemplated therein, in approving the Mergers and in recommending that EnLink unitholders approve the Merger Proposal and the Non-Binding Advisory Compensation Proposal.

Litigation relating to the Mergers could result in an injunction preventing completion of the Mergers, substantial costs to ONEOK and EnLink and/or may adversely affect ONEOK’s business, financial condition or results of operations following the Mergers.

Securities class action lawsuits and derivative lawsuits are often brought against public companies that have entered into acquisition, merger or other business combination agreements. Even if such a lawsuit is without merit, defending against these claims can result in substantial costs and divert management time and resources. An adverse judgment could result in monetary damages, which could have a negative impact on ONEOK’s and EnLink’s respective liquidity and financial condition.

Lawsuits that may be brought against ONEOK, EnLink or their respective directors could also seek, among other things, injunctive relief or other equitable relief, including a request to rescind parts of the Merger Agreement already implemented and to otherwise enjoin the parties from consummating the Mergers. One of the conditions to the closing of the Mergers is that no injunction by any court or other tribunal of competent jurisdiction has been entered and continues to be in effect and no law has been adopted or is effective, in either case that prohibits or makes illegal the closing of the Mergers. Consequently, if a plaintiff is successful in obtaining an injunction prohibiting completion of the Mergers, that injunction may delay or prevent the Mergers from being completed within the expected timeframe or at all, which may adversely affect ONEOK’s and EnLink’s respective business, financial position and results of operation.

There can be no assurance that any of the defendants will be successful in the outcome of any pending or any potential future lawsuits. The defense or settlement of any lawsuit or claim that remains unresolved at the time the Mergers are completed may adversely affect ONEOK’s and EnLink’s business, financial condition, results of operations and cash flows.

EnLink unitholders will not be entitled to appraisal rights in the Mergers.

Appraisal rights are statutory rights that enable security holders to dissent from certain extraordinary transactions, such as certain mergers, and to demand that the company pay the fair value for their securities as determined by a court in a judicial proceeding instead of receiving the consideration offered to security holders in connection with the applicable transaction. Under the DLLCA and the EnLink Operating Agreement, EnLink unitholders do not have appraisal rights in connection with the Mergers, as more fully described in “The Mergers — No Appraisal Rights.”

Declaration, payment and amounts of dividends, if any, distributed to ONEOK shareholders following the Mergers will be uncertain.

Although ONEOK has paid cash dividends on ONEOK Common Stock in the past, ONEOK may determine not to declare dividends in the future or may reduce the amount of dividends paid in the future. Any payment of future dividends will be at the discretion of the ONEOK Board and will depend on ONEOK’s results of operations, financial condition, cash requirements, future prospects and other considerations that the ONEOK Board deems relevant, including, but not limited to:

•        ONEOK may not have enough cash to pay such dividends or to repurchase shares due to its cash requirements, capital spending plans, cash flow or financial position;

•        decisions on whether, when and in which amounts to make any future distributions will remain at all times entirely at the discretion of the ONEOK Board, which could change its dividend practices at any time and for any reason;

•        ONEOK’s desire to maintain or improve the credit ratings on its debt;

•        the amount of dividends that ONEOK may distribute to its shareholders is subject to restrictions under Oklahoma law; and

•        the agreements governing ONEOK’s indebtedness.

Shareholders should be aware that they have no contractual or other legal right to dividends that have not been declared.

The trading price and volume of ONEOK Common Stock may be volatile following the Mergers.

The trading price and volume of ONEOK Common Stock may be volatile following completion of the Mergers. The stock markets in general have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. These broad market fluctuations may adversely affect the trading price of ONEOK Common Stock. As a result, ONEOK shareholders and EnLink unitholders who receive ONEOK Common Stock may suffer a loss on their investment. Many factors may impair the market for ONEOK Common Stock and the ability of investors to sell shares at an attractive price and could also cause the market price and demand for ONEOK Common Stock to fluctuate substantially, which may negatively affect the price and liquidity of ONEOK Common Stock. Many of these factors and conditions are beyond the control of ONEOK or its shareholders.

Following the consummation of the Mergers, the market price of ONEOK Common Stock may be depressed by the perception that former EnLink unitholders may sell the shares of ONEOK Common Stock they will acquire at closing and for other reasons related to the Mergers.

Subject to applicable securities laws, former EnLink unitholders may seek to sell shares of ONEOK Common Stock held by them immediately following the consummation of the Mergers. The Merger Agreement contains no restriction on their ability to sell such shares of ONEOK Common Stock. These sales (or the perception that these sales may occur), coupled with the increase in the outstanding number of shares of ONEOK Common Stock, may affect the market for, and the market price of, shares of ONEOK Common Stock in an adverse manner.

The financial forecasts are based on various assumptions that may not be realized.

The financial estimates set forth in the forecasts included under the section entitled “The Mergers — Certain Unaudited Forecasted Financial Information of EnLink” were based on assumptions of, and information available to, EnLink management when prepared, and these estimates and assumptions are subject to uncertainties, many of which are beyond ONEOK’s and EnLink’s control and may not be realized. Many factors mentioned in this proxy statement/prospectus, including the risks outlined in this “Risk Factors” section and the events or circumstances described under “Cautionary Statement Regarding Forward-Looking Statements,” will be important in determining ONEOK’s future results. As a result of these contingencies, actual future results may vary materially from EnLink’s

estimates. In view of these uncertainties, the inclusion of financial estimates in this proxy statement/prospectus is not and should not be viewed as a representation that the forecasted results will necessarily reflect actual future results.

EnLink’s financial estimates were not prepared with a view toward public disclosure, and such financial estimates were not prepared with a view toward compliance with published guidelines of any regulatory or professional body. Further, any forward-looking statement speaks only as of the date on which it is made, and neither ONEOK nor EnLink undertakes any obligation, other than as required by applicable law, to update the financial estimates herein to reflect events or circumstances after the date those financial estimates were prepared or to reflect the occurrence of anticipated or unanticipated events or circumstances.

The prospective financial information included in this document has been prepared by, and is the responsibility of, EnLink’s management. Neither KPMG LLP nor PricewaterhouseCoopers LLP has not audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying prospective financial information and, accordingly, neither KPMG LLP nor PricewaterhouseCoopers LLP express an opinion or any other form of assurance with respect thereto. The report of KPMG LLP contained in EnLink’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of EnLink, and such report does not extend to the Forecasted Financial Information and should not be read to do so. In addition, the PricewaterhouseCoopers LLP report incorporated by reference in this document relates to ONEOK’s previously issued financial statements. It does not extend to the prospective financial information and should not be read to do so. For more information, please see the section entitled “The Mergers — Certain Unaudited Forecasted Financial Information of EnLink.”

The opinion of Evercore, the financial advisor to the EnLink Conflicts Committee, speaks only as of the date rendered based on circumstances and conditions existing as of the signing of the Merger Agreement and will not reflect changes in circumstances between the signing of the Merger Agreement and the completion of the Mergers.

The EnLink Conflicts Committee has received an opinion from its financial advisor, Evercore, in connection with the signing of the Merger Agreement based on circumstances and conditions existing at that time but has not obtained any updated opinion from its financial advisor as of the date of this proxy statement/prospectus. Changes in the operations and prospects of ONEOK or EnLink, general market and economic conditions and other factors that may be beyond the control of ONEOK or EnLink, and on which the EnLink Conflicts Committee’s financial advisor’s opinion was based, may significantly alter the value of ONEOK or EnLink or the prices of the shares of ONEOK Common Stock or EnLink Units by the time the Mergers are completed. The opinion does not speak as of the time the Mergers will be completed or as of any date other than the date of the opinion. Because the EnLink Conflicts Committee currently does not anticipate asking its financial advisor to update its opinion, the opinion will not address the fairness of the Merger Consideration from a financial point of view at the time the Mergers are completed. The EnLink Conflicts Committee’s recommendation that EnLink unitholders vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, however, is made as of the date of this proxy statement/prospectus.

The synergies attributable to the Mergers may vary from expectations.

ONEOK may fail to realize the anticipated benefits and synergies expected from the Mergers, which could adversely affect its business, financial condition and operating results. The success of the Mergers will depend, in significant part, on ONEOK’s ability to successfully integrate EnLink’s business, grow its revenue and realize the anticipated strategic benefits and synergies from the Mergers. ONEOK believes that the Mergers will provide operational and financial scale, increasing free cash flow, and enhancing its corporate rate of return. However, achieving these goals requires, among other things, realization of the targeted cost and commercial synergies expected from the Mergers. This growth and the anticipated benefits of the Mergers may not be realized fully or at all or may take longer to realize than expected. Actual operating, technological, strategic and revenue opportunities, if achieved at all, may be less significant than expected or may take longer to achieve than anticipated. If ONEOK is not able to achieve these objectives and realize the anticipated benefits and synergies expected from the Mergers within the anticipated timing or at all, ONEOK’s business, financial condition and operating results may be adversely affected, its earnings per share may be diluted, the accretive effect of the Mergers may decrease or be delayed and its share price may be negatively impacted.

The future results of ONEOK following the Mergers will suffer if it does not effectively manage its expanded operations.

Following the Mergers, the size of the business of ONEOK will increase. ONEOK’s future success will depend, in part, upon its ability to manage this expanded business, which may pose challenges for management, including challenges related to the management and monitoring of new operations and associated increased costs and complexity. ONEOK may also face increased scrutiny from governmental authorities as a result of the increase in the size of its business. There can be no assurances that ONEOK will be successful or that it will realize the expected operating efficiencies, cost savings, revenue enhancements or other benefits currently anticipated from the Mergers.

The pendency of the Mergers and/or the completion of the Mergers may result in a loss of customers, suppliers, vendors, landlords, joint venture partners and other business partners and may result in the termination of existing contracts.

In connection with the pending Mergers, some of the customers, suppliers, vendors, landlords, joint venture partners and other business partners of each of ONEOK and EnLink may delay or defer decisions, which could adversely affect the revenues, earnings, funds from operations, cash flows and expenses of ONEOK and EnLink, regardless of whether the Mergers are completed, and of the combined company, if the Mergers are completed.

Following the Mergers, some of the customers, suppliers, vendors, landlords, joint venture partners and other business partners of ONEOK or EnLink may terminate or scale back their current or prospective business relationships with ONEOK. Some customers may not wish to source a larger percentage of their needs from a single company or may feel that ONEOK is too closely allied with one of their competitors. In addition, EnLink has contracts with customers, suppliers, vendors, landlords, joint venture partners and other business partners that may require EnLink to obtain consents from these other parties in connection with the Mergers, which may not be obtained on favorable terms or at all. If relationships with customers, suppliers, vendors, landlords, joint venture partners and other business partners are adversely affected by the Mergers, or if ONEOK, following the Mergers, loses the benefits of the contracts of EnLink, ONEOK’s business and financial performance could suffer.

ONEOK shareholders may experience dilution in the future.

The percentage ownership of ONEOK shareholders may be diluted in the future because of equity issuances for acquisitions, capital market transactions or otherwise, including, without limitation, equity awards that ONEOK may grant to its directors, officers and employees and pursuant to ONEOK “at-the-market” offerings of ONEOK Common Stock. Such issuances may have a dilutive effect on ONEOK’s earnings per share, which could adversely affect the market price of ONEOK Common Stock.

Certain employees of EnLink will have rights to purchase or receive shares of ONEOK Common Stock after the Mergers as a result of the conversion of their EnLink equity awards into ONEOK equity awards. The conversion of these EnLink equity awards into ONEOK equity awards is described in further detail in the section entitled “The Merger Agreement — Treatment of EnLink Equity Awards.” The issuance of shares of ONEOK Common Stock pursuant to these awards will dilute the percentage ownership of ONEOK shareholders. It is also expected that, from time to time after the closing of the Mergers, the Executive Compensation Committee of the ONEOK Board will grant additional equity awards to employees and directors under ONEOK’s compensation and employee benefit plans. These additional equity awards will have a dilutive effect on ONEOK’s earnings per share, which could adversely affect the market price of ONEOK Common Stock.

Further, pursuant to ONEOK’s “at-the-market” equity program, it can, but is under no obligation to, offer and sell ONEOK Common Stock up to an aggregate offering price of $1.0 billion. The program allows ONEOK to offer and sell ONEOK Common Stock at prices it deems appropriate through a sales agent, in forward sales transactions through a forward seller or directly to one or more of the program’s managers acting as principals. Sales of ONEOK Common Stock may be made by means of ordinary brokers’ transactions on the NYSE, in block transactions or as otherwise agreed to between ONEOK and the sales agent. As of September 30, 2024, no sales have been made under ONEOK’s “at-the-market” program.

In addition, the Amended and Restated Certificate of Incorporation of ONEOK, as amended (the “ONEOK Charter”), authorizes ONEOK to issue, without the approval of ONEOK shareholders, one or more classes or series of preferred stock having such designations, powers, preferences and relative, participating, optional and other special rights, including preferences over ONEOK Common Stock with respect to dividends and distributions, as the ONEOK Board generally may determine. The terms of one or more classes or series of preferred stock could dilute the voting power or reduce the value of ONEOK Common Stock. For example, the repurchase or redemption rights or liquidation preferences that could be assigned to holders of preferred stock could affect the residual value of ONEOK Common Stock. For more information, please see the section entitled “Comparison of Rights of EnLink Unitholders and ONEOK Shareholders.”

ONEOK has a significant amount of indebtedness, which will limit its liquidity and financial flexibility, and any downgrade of its credit rating could adversely impact ONEOK. ONEOK may also incur additional indebtedness in the future.

As of September 30, 2024, ONEOK and EnLink had total indebtedness of approximately $28.1 billion and $4.9 billion, respectively. Accordingly, ONEOK will have substantial indebtedness following completion of the Mergers. In addition, subject to the limits contained in the documents governing such indebtedness, ONEOK may be able to incur substantial additional debt from time to time to finance working capital, capital expenditures, investments or acquisitions or for other purposes. ONEOK’s indebtedness and other financial commitments have important consequences to its business, including, but not limited to:

•        making it more difficult for ONEOK to satisfy its obligations with respect to senior notes and other indebtedness due to the increased debt-service obligations, which could, in turn, result in an event of default on such other indebtedness or the senior notes;

•        requiring ONEOK to dedicate a substantial portion of its cash flows from operations to debt service payments, thereby limiting its ability to fund working capital, capital expenditures, investments or acquisitions and other general corporate purposes;

•        increasing ONEOK’s vulnerability to general adverse economic and industry conditions, including low commodity price environments;

•        limiting ONEOK’s ability to obtain additional financing due to higher costs and more restrictive covenants;

•        limiting ONEOK’s flexibility in planning for, or reacting to, changes in its business and the industry in which it operates; and

•        placing ONEOK at a competitive disadvantage compared with its competitors that have proportionately less debt and fewer guarantee obligations.

In addition, ONEOK and EnLink receive credit ratings from rating agencies in the U.S. with respect to their indebtedness. Any credit downgrades resulting from the Mergers or otherwise could adversely impact ONEOK’s ability to access financing and trade credit, require ONEOK to offer to repurchase certain of EnLink’s outstanding senior notes, require ONEOK to provide additional letters of credit or other assurances under contractual arrangements and increase ONEOK’s interest rate under any credit facility borrowing as well as the cost of any other future debt.

Other Risk Factors Relating to ONEOK and EnLink

As a result of entering into the Merger Agreement, ONEOK’s and EnLink’s businesses are and will be subject to the risks described above. In addition, ONEOK and EnLink are, and following completion of the Mergers, ONEOK will be, subject to the risks described in ONEOK’s and EnLink’s most recent Annual Report on Form 10-K (as amended) as updated by subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. Please see the section entitled “Where You Can Find More Information” for the location of information incorporated by reference into this proxy statement/prospectus.

Tax Risks Related to the Mergers and the Ownership of ONEOK Common Stock Received in the Mergers

In addition to reading the following risk factors, you are strongly urged to read “Material U.S. Federal Income Tax Consequences” for a more complete discussion of the expected U.S. federal income tax consequences of the Mergers and owning and disposing of shares of ONEOK Common Stock received in the Mergers.

There could be limitations on the utilization of the historic U.S. net operating loss carryforwards of EnLink.

ONEOK’s ability to utilize EnLink’s historic U.S. net operating loss carryforwards to reduce future taxable income following the consummation of the Mergers is expected to be subject to various limitations under the Code.

In general, Section 382 of the Code imposes such a limitation upon the occurrence of ownership changes resulting from issuances of a company’s stock or the sale or exchange of such company’s stock by certain shareholders if, as a result, there is an aggregate change of more than 50% in the beneficial ownership of such company’s stock by such shareholders during any three-year period. The limitation (a “Section 382 limitation”) with respect to the loss carryforwards of a company that has undergone such an ownership change generally is equal to (i) the fair market value of such company’s equity multiplied by (ii) a percentage approximately equivalent to the yield on long-term tax-exempt bonds during the month in which the ownership change occurs. In addition, the Section 382 limitation is increased if there are recognized built-in gains during the five-year post-change period, but only to the extent of any net unrealized built-in gain existing on the date of the ownership change. If a corporation that is already subject to a Section 382 limitation as a result of an ownership change undergoes a second ownership change, net operating losses attributable to the period preceding the earlier ownership change are treated as pre-change losses with respect to both ownership changes. The second ownership change may result in a lesser, but never a greater, Section 382 limitation following such ownership change.

ONEOK and EnLink believe that the transactions in connection with the Mergers, if consummated, will result in an ownership change under Section 382 of the Code with respect to EnLink. As a result, ONEOK could be subject to the Section 382 limitation with respect to EnLink’s loss carryforwards that exist on the date of the Mergers.

For a more complete discussion of the U.S. federal income tax consequences of the Mergers, see the section entitled “Material U.S. Federal Income Tax Consequences.”

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Certain statements and information in this document may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. All statements, other than statements of historical fact, included in this document that address activities, events or developments that ONEOK or EnLink expects, believes or anticipates will or may occur in the future are forward-looking statements. Words such as “estimate,” “project,” “predict,” “believe,” “expect,” “anticipate,” “potential,” “opportunity,” “create,” “intend,” “could,” “would,” “may,” “plan,” “will,” “guidance,” “look,” “goal,” “target,” “future,” “build,” “focus,” “continue,” “strive,” “allow” or the negative of such terms or other variations thereof and words and terms of similar substance used in connection with any discussion of future plans, actions, or events identify forward-looking statements. However, the absence of these words does not mean that the statements are not forward-looking. These forward-looking statements include, but are not limited to, statements regarding the Mergers, the expected closing of the Mergers and the timing thereof, and descriptions of ONEOK following the consummation of the Mergers and its operations, strategies and plans, integration, debt levels and leverage ratio, capital expenditures, cash flows and anticipated uses thereof, synergies, opportunities and anticipated future performance, including maintaining current ONEOK management, enhancements to investment-grade credit profile, an expected accretion to earnings and free cash flow, dividend payments and potential share repurchases, increase in value of tax attributes and expected impact on EBITDA after giving effect to the Mergers. Information adjusted for the Mergers should not be considered a forecast of future results. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this proxy statement/prospectus. These include the risk that ONEOK will not be able to successfully integrate EnLink’s business; the risk that cost savings, synergies and growth from the Mergers may not be fully realized or may take longer to realize than expected; the risk that the credit ratings following the Mergers may be different from what the companies expect; the risk that a condition to closing of the Mergers may not be satisfied, that a party may terminate the Merger Agreement or that the closing of the Mergers might be delayed or not occur at all; the possibility that the EnLink unitholders may not approve the Merger Proposal; the risk of potential adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the Mergers; risks related to the occurrence of any other event, change or circumstance that could give rise to the termination of the Merger Agreement; the risk that changes in ONEOK’s capital structure could have adverse effects on the market value of its securities; risks related to the ability of ONEOK and EnLink to retain customers and retain and hire key personnel and maintain relationships with their suppliers and customers and on ONEOK’s and EnLink’s operating results and business generally; the risk that the Mergers could distract ONEOK’s and EnLink’s respective management teams from ongoing business operations or cause ONEOK and/or EnLink to incur substantial costs; the risk of any litigation relating to the Mergers; risks related to the impact of any economic downturn and any substantial decline in commodity prices; the risk of changes in governmental regulations or enforcement practices, especially with respect to environmental, health and safety matters; and other important factors that could cause actual results to differ materially from those projected. All such factors are difficult to predict and are beyond ONEOK’s or EnLink’s control, including those detailed in ONEOK’s Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K that are available on ONEOK’s website at www.oneok.com and on the website of the SEC at www.sec.gov, and those detailed in EnLink’s Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K that are available on EnLink’s website at www.enlink.com and on the website of the SEC. All forward-looking statements are based on assumptions that ONEOK and EnLink believe to be reasonable but that may not prove to be accurate. Any forward-looking statement speaks only as of the date on which such statement is made, and neither ONEOK nor EnLink undertakes any obligation to correct or update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by applicable law. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.

PARTIES TO THE MERGERS

ONEOK, Inc.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

ONEOK is an Oklahoma corporation, and its common stock is listed on the NYSE under the ticker symbol “OKE.” ONEOK delivers energy products and services vital to an advancing world. ONEOK is a leading midstream service provider of gathering, processing, fractionation, transportation, storage and marine exports. As one of the largest diversified energy infrastructure companies in North America, ONEOK delivers energy that makes a difference in the lives of people in the U.S. and around the world. Through its more than 50,000-mile pipeline network, ONEOK transports natural gas, NGLs, the output from crude oil refineries, including products such as gasoline, diesel fuel, aviation fuel, kerosene and heating oil and crude oil that help meet domestic and international energy demand, contribute to energy security and provide safe, reliable and responsible energy solutions needed today and into the future.

On October 15, 2024, pursuant to the GIP Interest Purchase Agreement, ONEOK acquired 200,340,753 EnLink Units, representing approximately [            ]% of the EnLink Units outstanding as of the date of this proxy statement/prospectus. Pursuant to the terms of the Support Agreement, ONEOK has irrevocably agreed to vote such EnLink Units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. For additional information regarding the GIP Interest Acquisition and the Support Agreement, please see the sections entitled “The Mergers — Background of the Mergers” and “The Mergers — Support Agreement.”

Additional information about ONEOK and its subsidiaries, including, but not limited to, information regarding its business, properties, legal proceedings, financial statements, financial condition and results of operations, market risk, executive compensation and related party transactions is set forth in ONEOK’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, and ONEOK’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024, which are each incorporated by reference into this document.

For more information about ONEOK, please visit ONEOK’s website at www.oneok.com. The information contained on ONEOK’s website or accessible through it does not constitute a part of this document.

EnLink Midstream, LLC

1722 Routh Street, Suite 1300
Dallas, Texas 75201
(214) 953-9500

EnLink is a publicly traded Delaware limited liability company formed in October 2013. Its assets consist of all of the outstanding common units of ENLK and all of the membership interests of ENLK GP. All of EnLink’s midstream energy assets are owned and operated by ENLK and its subsidiaries. EnLink primarily focuses on owning, operating, investing in, and developing midstream energy infrastructure assets to provide midstream energy services, including (i) gathering, compressing, treating, processing, transporting, storing, and selling natural gas; (ii) fractionating, transporting, storing, and selling NGLs; and (iii) gathering, transporting, storing, trans-loading, and selling crude oil and condensate. EnLink Units are listed on the NYSE under the ticker symbol “ENLC.”

Additional information about EnLink and its subsidiaries, including, but not limited to, information regarding its business, properties, legal proceedings, financial statements, financial condition and results of operations, executive compensation and related party transactions is set forth in EnLink’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 and EnLink’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024, which are each incorporated by reference into this document.

For more information about EnLink, please visit EnLink’s website at www.enlink.com. The information contained on EnLink’s website or accessible through it does not constitute a part of this document.

Elk Merger Sub I, L.L.C.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Merger Sub I is a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK. Merger Sub I has not carried on any activities to date, other than activities incidental to its formation or undertaken in connection with the transactions contemplated by the Merger Agreement.

Elk Merger Sub II, L.L.C.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Merger Sub II is a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK. Merger Sub II has not carried on any activities to date, other than activities incidental to its formation or undertaken in connection with the transactions contemplated by the Merger Agreement.

EnLink Midstream Manager, LLC

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Manager is a Delaware limited liability company and sole managing member of EnLink. Manager is responsible for conducting the business and managing the operations of EnLink. As of the consummation of the GIP Interest Acquisition on October 15, 2024, ONEOK owns all limited liability company interests in Manager.

SPECIAL MEETING OF ENLINK UNITHOLDERS

General

This proxy statement/prospectus is first being mailed on or about [        ], 2024 and constitutes notice of the EnLink Special Meeting in conformity with the requirements of the EnLink Operating Agreement.

This proxy statement/prospectus is being provided to EnLink unitholders as part of a solicitation of proxies by the EnLink Board for use at the EnLink Special Meeting, including any adjournment or postponement of the EnLink Special Meeting. EnLink unitholders are encouraged to read the entire document carefully, including the annexes to this document, for more detailed information regarding the Merger Agreement and the transactions contemplated by the Merger Agreement.

Date, Time and Place

The EnLink Special Meeting will be held virtually at [        ], on [        ], 2025, at [        ], Central Time. The EnLink Special Meeting can be accessed by visiting [        ], where EnLink unitholders will be able to participate and vote online. This proxy statement/prospectus is first being furnished to EnLink’s unitholders on or about [        ], 2024.

Purpose of the EnLink Special Meeting

At the EnLink Special Meeting, EnLink unitholders will be asked to consider and vote on the following:

1.      the Merger Proposal; and

2.      the Non-Binding Advisory Compensation Proposal.

EnLink does not intend to transact any other business at the EnLink Special Meeting or any adjournment or postponement thereof, except such business as may properly be brought before the EnLink Special Meeting by or at the direction of the EnLink Board in accordance with the EnLink Operating Agreement. This proxy statement/prospectus, including the Merger Agreement attached thereto as Annex A, contains further information with respect to these matters.

Recommendation of the EnLink Conflicts Committee and the EnLink Board

The EnLink Conflicts Committee unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

For a description of factors considered by the EnLink Conflicts Committee in reaching its decision to approve and declare advisable the foregoing proposals, please see the section entitled “The Mergers — Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers” beginning on page 40.

The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

EnLink unitholders’ approval of the Merger Proposal is a condition for the Mergers to occur. If EnLink unitholders fail to approve the Merger Proposal by the requisite vote, the Mergers will not occur. The Non-Binding Advisory Compensation Proposal is not a condition to the consummation of the Mergers.

Record Date; Unitholders Entitled to Vote

Only EnLink unitholders at the close of business on [        ], 2024, the Record Date for the EnLink Special Meeting, will be entitled to notice of, and to vote at, the EnLink Special Meeting or any adjournment or postponement of the EnLink Special Meeting. At the close of business on the Record Date, [        ] EnLink Units were issued and outstanding.

EnLink unitholders are entitled to one vote for each EnLink Unit they own at the close of business on the Record Date.

Quorum; Adjournment

The presence at the EnLink Special Meeting of the holders of a majority of the outstanding EnLink Units entitled to vote at the meeting as of the close of business on the Record Date, represented in person or by proxy, will constitute a quorum. As a result, there must be [        ] EnLink Units represented by proxy or by unitholders present and entitled to vote at the EnLink Special Meeting in order to have a quorum and, for business to be conducted at the EnLink Special Meeting, a quorum must be present. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The Manager may adjourn the meeting from time to time, whether or not there is a quorum. Failure of a quorum to be represented at the EnLink Special Meeting will result in an adjournment of the EnLink Special Meeting and may subject EnLink to additional expense. Even if a quorum is present, the EnLink Special Meeting may also be adjourned in order to provide more time to solicit additional proxies in favor of approval of the Merger Proposal if the Manager determines such adjournment is necessary.

Notice need not be given of the adjourned meeting and a new record date need not be fixed if the time and place thereof are announced at the meeting at which the adjournment is taken unless the adjournment is for more than 45 days, in which case a notice of the adjourned meeting will be given to each unitholder of record entitled to vote at the meeting. If after the adjournment a new record date for the unitholders entitled to vote is fixed for the adjourned meeting, the EnLink Board must fix a record date for the adjourned meeting in accordance with the DLLCA and provide a new notice of the adjourned meeting to each unitholder of record entitled to vote at the meeting. In addition, prior to the date of the EnLink Special Meeting, the Manager may postpone the EnLink Special Meeting one or more times for any reason by giving at least two days’ prior notice to the EnLink unitholders entitled to vote at such meeting in accordance with the EnLink Operating Agreement.

If the EnLink Special Meeting is adjourned or postponed for the purpose of soliciting additional votes, unitholders who have already submitted their proxies will be able to revoke them at any time prior to the final vote on the proposals. If you submit your proxy over the Internet or by telephone or submit a properly executed proxy card, even if you abstain from voting, your units will be counted as present for purposes of determining whether a quorum exists at the EnLink Special Meeting.

Required Vote

Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, with respect to an EnLink unitholder who is present in person or represented by proxy at the EnLink Special Meeting, such unitholder’s abstention from voting will have

the same effect as a vote “against” the Merger Proposal. Additionally, the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee will have the same effect as a vote “against” the Merger Proposal.

Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, with respect to an EnLink unitholder who is present in person or represented by proxy at the EnLink Special Meeting, such unitholder’s abstention from voting will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. Additionally, the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers.

The Mergers are conditioned on, among other things, the approval of the Merger Proposal at the EnLink Special Meeting. The Non-Binding Advisory Compensation Proposal is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.

Abstentions and Broker Non-Votes

An abstention occurs when a unitholder attends a meeting, either in person or by proxy, but abstains from voting. At the EnLink Special Meeting, abstentions will be counted as present for purposes of determining whether a quorum exists. Abstaining from voting will have the same effect as voting “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

If no instruction as to how to vote is given (including no instruction to abstain from voting) in an executed, duly returned and not revoked proxy, the proxy will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Broker non-votes occur when (i) a bank, broker or other nominee has discretionary authority to vote on one or more proposals to be voted on at a meeting of unitholders but is not permitted to vote on other proposals without instructions from the beneficial owner of the units and (ii) the beneficial owner fails to provide the bank, broker or other nominee with such instructions. Under NYSE rules, banks, brokers and other nominees holding units in “street name” do not have discretionary voting authority with respect to any of the EnLink proposals described in this proxy statement/prospectus. Accordingly, if a beneficial owner of EnLink Units held in “street name” does not give voting instructions to the bank, broker or other nominee, then those units will not be counted as present in person or by proxy at the EnLink Special Meeting and will have the same effect as voting “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

Failure to Vote

If you are a unitholder of record and you do not sign and return your proxy card or submit your proxy over the Internet, by telephone or at the EnLink Special Meeting, your units will not be voted at the EnLink Special Meeting, will not be counted as present in person or by proxy at the EnLink Special Meeting and will not be counted as present for purposes of determining whether a quorum exists.

For purposes of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, provided a quorum is present, a failure to vote, or a failure to instruct your bank, broker, trust or other nominee to vote, will have the same effect as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

An abstention from voting will have the same effect as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

If you sign, date and return your proxy card and do not indicate how you want your EnLink Units to be voted, then your EnLink Units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

Voting by EnLink’s Directors and Executive Officers

At the close of business on [            ], 2024, latest practicable date prior to the date of this proxy statement/prospectus, directors and executive officers of EnLink were entitled to vote [        ] EnLink Units, or approximately [        ]% of the EnLink Units issued and outstanding on that date. EnLink currently expects that all of its directors and executive officers will vote their units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, although none of the directors and executive officers are obligated to do so.

Voting by ONEOK

At the close of business on [            ], 2024, the latest practicable date prior to the date of this proxy statement/prospectus, ONEOK was entitled to vote [            ] EnLink Units, or approximately [            ]% of the EnLink Units issued and outstanding on that date. Pursuant to the terms of the Support Agreement, ONEOK has irrevocably agreed to vote such units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal.

Voting at the EnLink Special Meeting

The EnLink Special Meeting will be a completely virtual meeting. There will be no physical meeting location and the meeting will only be conducted via live webcast. The virtual EnLink Special Meeting will be held on [        ], 2025, at [        ], Central Time. To participate in the EnLink Special Meeting and submit questions during the special meeting, visit [        ] and enter the control number on the proxy card, voting instruction form or notice you received. Online check-in will begin at [        ], Central Time. Please allow time for online check-in procedures.

The virtual unitholder meeting format uses technology designed to increase unitholder access, save EnLink and EnLink unitholders time and money, and provide EnLink unitholders rights and opportunities to participate in the meeting similar to what they would have at an in-person meeting. In addition to online attendance, EnLink provides unitholders with an opportunity to hear all portions of the official meeting, submit written questions and comments during the meeting, and vote online during the open poll portion of the meeting. Although EnLink offers four different methods to submit a proxy, EnLink encourages you to submit a proxy either over the Internet or by telephone to ensure that your units are represented and voted at the EnLink Special Meeting.

•        To Submit a Proxy over the Internet:    To submit a proxy over the Internet, follow the instructions provided on your proxy card. You will need the number included on your proxy card to obtain your records and to create an electronic voting instruction form. If you submit your proxy over the Internet, you do not have to mail in a proxy card. If you choose to submit your proxy over the Internet, you must do so prior to 11:59 p.m., Eastern Time, on [        ], 2025.

•        To Submit a Proxy by Telephone:    Registered unitholders may submit a proxy by telephone by calling the toll-free number provided on your proxy card on a touch-tone telephone. Please have your proxy card available for reference because you will need the validation details that are located on your proxy card in order to submit your proxy by telephone. If you submit your proxy by telephone, you do not have to mail in a proxy card. If you choose to submit your proxy by telephone, you must do so prior to 11:59 p.m., Eastern Time, on [        ], 2025.

•        To Submit a Proxy by Mail:    To submit a proxy by mail, complete, sign and date the proxy card and return it promptly to the address indicated on the proxy card in the postage paid enveloped provided. If you sign and return your proxy card without indicating how you want your EnLink Units to be voted with regard to a particular proposal, your EnLink Units will be voted in favor of such proposal. If you return your proxy card without a signature, your units will not be counted as present at the EnLink Special Meeting and cannot be voted.

•        To Vote Virtually at the EnLink Special Meeting:    To vote virtually at the EnLink Special Meeting, follow the instructions at [        ].

If your units are held by your bank, broker or other nominee, you are considered the beneficial owner of units held in “street name” and you will receive a vote instruction form from your bank, broker or other nominee seeking instruction from you as to how your units should be voted.

If you sign your proxy, but do not indicate how you wish to vote, your units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Revocation of Proxies

You can change or revoke your proxy at any time before the final vote at the EnLink Special Meeting. If you are the unitholder of record of your EnLink Units, you may revoke your proxy by:

•        submitting another proxy over the Internet or by telephone prior to 11:59 p.m., Eastern Time, on [        ], 2025;

•        timely delivering a written notice that you are revoking your proxy to EnLink’s Secretary;

•        timely delivering a valid, later-dated proxy; or

•        attending the EnLink Special Meeting and voting. Your virtual attendance at the EnLink Special Meeting will not revoke your proxy unless you give written notice of revocation to EnLink’s Secretary before your proxy is exercised or unless you vote your units in person at the EnLink Special Meeting.

If you are the beneficial owner of units held in “street name,” you should contact your bank, broker or other nominee with questions about how to change or revoke your voting instructions.

Solicitation of Proxies

The EnLink Board is soliciting your proxy in connection with the EnLink Special Meeting, and EnLink will bear the cost of soliciting such proxies, including the costs of printing and filing this proxy statement/prospectus. EnLink has retained Innisfree M&A Incorporated as proxy solicitor to assist with the solicitation of proxies in connection with the EnLink Special Meeting. In addition to the reimbursement of expenses, EnLink agreed to pay Innisfree M&A Incorporated a fee of up to $75,000 for these services. Solicitation initially will be made by mail. Forms of proxies and proxy materials may also be distributed through banks, brokers and other nominees to the beneficial owners of EnLink Units, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses. Proxies may also be solicited in person or by telephone, facsimile, electronic mail, or other electronic medium by certain of EnLink’s directors, officers and employees, as applicable, without additional compensation.

Tabulation of Votes

[        ] will tabulate the votes at the EnLink Special Meeting.

No Appraisal Rights

Under the DLLCA, EnLink unitholders are not entitled to appraisal or dissenters’ rights in connection with the Mergers. For additional information, please see the section entitled “The Mergers — No Appraisal Rights.”

Householding of EnLink Special Meeting Materials

Each registered EnLink unitholder will receive one copy of this proxy statement/prospectus per account, regardless of whether you have the same address as another unitholder of record. SEC rules permit companies and intermediaries such as brokers to satisfy delivery requirements for proxy statements and notices with respect to two or more unitholders sharing the same address by delivering a single proxy statement or a single notice addressed to those unitholders. This process, commonly called “householding,” provides cost savings for companies. Some brokers household proxy materials, delivering a single proxy statement or notice to multiple unitholders sharing an address unless contrary instructions have been received from the affected unitholders. For more details, please see the section entitled “Householding of Proxy Materials.”

Questions

If you have more questions about the Mergers or how to submit your proxy, or if you need additional copies of this proxy statement/prospectus or the enclosed proxy card or voting instructions, please contact EnLink’s Secretary, at EnLink’s principal executive offices at 1722 Routh Street, Suite 1300, Dallas, Texas 75201.

Assistance

If you need assistance voting or in completing your proxy card or have questions regarding the EnLink Special Meeting, please contact EnLink’s Solicitation Agent:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

ENLINK PROPOSAL 1 — THE MERGER PROPOSAL

This proxy statement/prospectus is being furnished to EnLink unitholders as part of the solicitation of proxies by the EnLink Board for use at the EnLink Special Meeting to consider and vote upon a proposal to approve the Merger Agreement, which is attached as Annex A to this proxy statement/prospectus, and the transactions contemplated thereby, including the Mergers.

The EnLink Conflicts Committee unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

Required Vote of EnLink Unitholders

The EnLink Conflicts Committee and the EnLink Board accordingly each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal to approve the Merger Agreement and the Mergers contemplated thereby, as disclosed in this proxy statement/prospectus, particularly the related narrative disclosures in the sections of this proxy statement/prospectus entitled “The Merger” and “The Merger Agreement” and as attached as Annex A to this proxy statement/prospectus.

Approval of the Merger Proposal is a condition to completion of the Mergers.

The vote on the Merger Proposal is a vote separate and apart from the vote to approve the Non-Binding Advisory Compensation Proposal. Accordingly, an EnLink unitholder may vote to approve the Merger Proposal and vote not to approve the Non-Binding Advisory Compensation Proposal, and vice versa.

Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote thereon. A failure to vote, a broker non-vote or an abstention will have the same effect as a vote “against” the Merger Proposal. Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

THE ENLINK CONFLICTS COMMITTEE AND THE ENLINK BOARD EACH UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE MERGER PROPOSAL.

ENLINK PROPOSAL 2 — THE NON-BINDING ADVISORY COMPENSATION PROPOSAL

EnLink is asking its unitholders to approve the Non-Binding Advisory Compensation Proposal.

As required by Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, which were enacted pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act, EnLink is required to provide its unitholders the opportunity to vote to approve, on a non-binding, advisory basis, certain compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers, as described in the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Quantification of Potential Payments to EnLink’s Named Executive Officers in Connection with the Mergers” beginning on page 59. Accordingly, EnLink unitholders are being provided the opportunity to cast an advisory vote on such payments.

As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers and is a vote separate and apart from the vote to approve the Merger Proposal. Accordingly, an EnLink unitholder may vote to approve the Non-Binding Advisory Compensation Proposal and vote not to approve the Merger Proposal, and vice versa. Because the executive compensation to be paid in connection with the Mergers is based on the terms of the Merger Agreement as well as the contractual arrangements with EnLink’s named executive officers, such compensation will be payable, regardless of the outcome of this advisory vote, only if the Merger Proposal is approved (subject only to the contractual conditions applicable thereto). However, EnLink seeks the support of its unitholders and believes that unitholder support is appropriate because EnLink has a comprehensive executive compensation program designed to link the compensation of the executives of EnLink with EnLink’s performance and the interests of EnLink unitholders.

Accordingly, EnLink unitholders are being asked to vote on the following resolution:

RESOLVED, that the unitholders of EnLink Midstream, LLC approve, on an advisory, non-binding basis, certain compensation that may be paid or become payable to the named executive officers of EnLink Midstream Manager, LLC that is based on or otherwise relates to the Mergers, as disclosed pursuant to Item 402(t) of Regulation S-K under the heading “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Quantification of Potential Payments to EnLink’s Named Executive Officers in Connection with the Mergers,” in the proxy statement/prospectus of EnLink Midstream, LLC with respect to the special meeting of unitholders to be held on [        ], 2025.

Required Vote of Unitholders

The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote thereon. A failure to vote, a broker non-vote or an abstention will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

THE ENLINK BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE NON-BINDING ADVISORY COMPENSATION PROPOSAL.

THE MERGERS

The following discussion contains certain information about the proposed Mergers. This discussion is subject, and qualified in its entirety by reference, to the Merger Agreement attached as Annex A to this proxy statement/prospectus. You are urged to carefully read this entire proxy statement/prospectus, including the Merger Agreement, before making any investment or voting decision.

Structure of the Mergers

Pursuant to the Merger Agreement, (i) at the First Merger Effective Time, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK. Following the Mergers, EnLink Units will be delisted from the NYSE, will be deregistered under the Exchange Act as promptly as practicable after the First Merger Effective Time and will cease to be publicly traded.

Support Agreement

In connection with the entry into the Merger Agreement, ONEOK and EnLink entered into the Support Agreement. Pursuant to the Support Agreement, ONEOK, which beneficially owns 200,340,753 EnLink Units, representing approximately [            ]% of the EnLink Units outstanding as of the date of this proxy statement/prospectus, has irrevocably agreed to vote such units (i) in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal; and (ii) against any action, agreement or transaction that would reasonably be expected to impede, interfere with, delay, postpone, discourage, frustrate the purposes of or adversely affect the merger or the other transactions contemplated by the Merger Agreement. The Support Agreement will terminate automatically upon the earliest to occur of (i) the First Merger Effective Time; (ii) the termination of the Merger Agreement in accordance with its terms, other than as a result of a breach by ONEOK of the terms of the Support Agreement; or (iii) the mutual agreement of the parties thereto.

The foregoing description of the Support Agreement is qualified in its entirety by reference to the full text of the Support Agreement, a copy of which is attached as Annex C to this proxy statement/prospectus and is incorporated into this proxy statement/prospectus by reference.

Background of the Mergers

On August 28, 2024, ONEOK announced that it executed a definitive agreement with GIP III Stetson I, L.P. and GIP III Stetson II, L.P. to acquire Global Infrastructure Partners’ (“GIP”) entire interest in EnLink, consisting of 43% of the EnLink Units for $14.90 per unit, and 100% of the interests in the Manager for $300 million, for total cash consideration of approximately $3.3 billion. As part of that announcement, ONEOK also publicly stated that, after the closing of the GIP Interest Acquisition, ONEOK intended to pursue the acquisition of the publicly owned equity interest in EnLink (the “EnLink Unaffiliated Units”) in a tax-free transaction.

In light of ONEOK’s publicly stated intention to pursue the acquisition of the EnLink Unaffiliated Units following closing of the GIP Interest Acquisition, on September 6, 2024, the EnLink Conflicts Committee, a representative of Baker Botts L.L.P. (“Baker Botts”) and EnLink management participated on a call to discuss the role of the EnLink Conflicts Committee in connection with a future potential transaction with ONEOK, the process for evaluating such a potential transaction, the role of the legal counsel and financial advisor to the EnLink Conflicts Committee and recommendations with respect thereto, the independence of the members of the EnLink Conflicts Committee and an indicative timeline with respect to the potential transaction.

Between September 6, 2024 and October 14, 2024, the EnLink Conflicts Committee had a series of preliminary meetings to interview potential financial advisors and legal counsel. The EnLink Conflicts Committee interviewed potential legal advisors, including Richards, Layton & Finger, P.A. (“RLF”), and determined, based on RLF’s experience with public mergers and acquisitions, complex transactions involving publicly traded limited partnerships and limited liability companies, RLF’s familiarity with EnLink and its business and representations of conflicts committees generally, that RLF had the requisite expertise and was

well qualified to advise the EnLink Conflicts Committee. On September 10, 2024, RLF was selected by the EnLink Conflicts Committee as legal counsel in connection with the potential transaction. The EnLink Conflicts Committee also interviewed potential financial advisors, including Evercore. Based on Evercore’s experience with public mergers and acquisitions, complex transactions involving publicly traded partnerships and limited liability companies, Evercore’s familiarity with EnLink and its business and representations of conflicts committees generally, the EnLink Conflicts Committee determined that Evercore had the requisite expertise and was well qualified to advise the EnLink Conflicts Committee.

On October 14, 2024, the EnLink Board delegated to the EnLink Conflicts Committee the power and authority (i) to make such investigation of the proposed transaction and the alternative of maintaining the status quo, as the EnLink Conflicts Committee deems necessary or appropriate; (ii) to review, evaluate and negotiate (or to supervise and direct the negotiations on behalf of EnLink with respect to) the terms and conditions, and determine the advisability, of the proposed transaction and related agreements and arrangements; (iii) to determine whether the proposed transaction is in, or not opposed to, the best interests of EnLink; (iv) to determine whether to approve the proposed transaction (with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof), and to make a recommendation to the EnLink Board whether to approve the proposed transaction and, if appropriate, to recommend that the EnLink unitholders approve the proposed transaction; and (v) to make any other recommendations to the EnLink Board and/or the EnLink unitholders regarding the proposed transaction as the EnLink Conflicts Committee determines to be appropriate.

On October 15, 2024, ONEOK and GIP closed the GIP Interest Acquisition, and Pierce H. Norton II, President and Chief Executive Officer of ONEOK, Walter S. Hulse III, Chief Financial Officer, Treasurer, and Executive Vice President, Investor Relations and Corporate Development of ONEOK, and Lyndon C. Taylor, Executive Vice President, Chief Legal Officer and Assistant Secretary of ONEOK, were appointed to serve as members of the EnLink Board, with Mr. Norton serving as the Chairman of the EnLink Board.

On October 17, 2024, the EnLink Conflicts Committee met with representatives of ONEOK and RLF. The ONEOK representatives informed the EnLink Conflicts Committee that ONEOK successfully closed the GIP Interest Acquisition and that an offer to acquire the EnLink Unaffiliated Units would be forthcoming the next day.

On October 18, 2024, ONEOK delivered an unsolicited, non-binding proposal (the “Initial ONEOK Offer”) to Tiffany Cepak, the Chair of the EnLink Conflicts Committee, setting forth certain terms of the proposed tax-free transaction, pursuant to which ONEOK would acquire all of the outstanding EnLink Unaffiliated Units in exchange for shares of ONEOK Common Stock equal to consideration of $14.70 per EnLink Unit. Accompanying the Initial ONEOK Offer was an initial draft of the Merger Agreement prepared by representatives of Kirkland & Ellis LLP (“K&E”), legal counsel to ONEOK. The initial draft of the Merger Agreement provided, among other terms, (i) that the EnLink Board or the EnLink Conflicts Committee could only effect an adverse recommendation change if an intervening event occurred and if the EnLink Board or the EnLink Conflicts Committee, as applicable, after consultation with its financial advisors and outside legal counsel, determined in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law; (ii) for a “force the vote” provision that required EnLink to hold the EnLink Special Meeting even if the EnLink Board or the EnLink Conflicts Committee made an adverse recommendation change; (iii) for the approval of the Mergers by the holders of a majority of the EnLink Units held by all EnLink unitholders; and (iv) that EnLink would be liable for a termination fee payable to ONEOK if ONEOK terminated the Merger Agreement prior to the EnLink unitholder approval due to an adverse recommendation change. The Merger Agreement did not contemplate delivery of a support agreement whereby ONEOK would agree to vote the EnLink Units it holds in favor of the Mergers.

On October 21, 2024, Evercore’s engagement as financial advisor to the EnLink Conflicts Committee was finalized pursuant to an engagement letter agreed to by the EnLink Conflicts Committee, EnLink and Evercore, and Evercore provided a letter documenting Evercore’s lack of recent relationships with EnLink, the Manager and ONEOK.

On October 22, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. The EnLink Conflicts Committee and its advisors reviewed and discussed a preliminary due diligence request list prepared by Evercore and the process for evaluating the proposed transaction and the Initial ONEOK Offer from a financial point of view. The EnLink Conflicts Committee instructed Evercore to finalize the due diligence request list, requesting certain financial, legal and other due diligence information with respect to EnLink and ONEOK, as

applicable. Following such meeting, Evercore sent an initial due diligence request list to the ONEOK management team, which the ONEOK management team sent to the EnLink management team to provide such requested information applicable to EnLink.

On October 28, 2024, the EnLink Conflicts Committee met with representatives of Evercore, RLF and management of EnLink. During the meeting, management of EnLink presented information on, among other things, the recent performance of EnLink, financial updates regarding EnLink and a business overview of EnLink and its assets. Following such meeting, the EnLink Conflicts Committee, representatives of Evercore and RLF and certain members of management of EnLink met with Mr. Hulse. Mr. Hulse presented the terms of, and the rationale for, the Initial ONEOK Offer. Mr. Hulse noted that, in connection with the GIP Interest Acquisition, ONEOK provided GIP with letters on June 24, 2024 and on July 11, 2024 proposing to acquire all of the equity interests in EnLink (collectively, the “GIP Offer Letters”). Mr. Hulse explained that GIP wanted to negotiate its sale of approximately 43% of the outstanding EnLink Units and all of the equity interests in the Manager separate from any negotiation regarding the acquisition of publicly held EnLink Units and, thus, ONEOK and GIP proceeded on that basis.

On October 29, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. The EnLink Conflicts Committee and its advisors discussed their reactions to the information presented by the representatives of management of EnLink and Mr. Hulse. During the meeting, the EnLink Conflicts Committee noted that they had not been aware of the existence of the GIP Offer Letters and instructed Evercore to request copies of those letters.

On October 30, 2024, Mr. Hulse provided copies of the GIP Offer Letters to the EnLink Conflicts Committee, Evercore and RLF.

On November 5, 2024, representatives of Baker Botts and RLF had a call with EnLink management to discuss the material terms of the initial draft of the Merger Agreement provided by K&E.

On November 7, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. During the meeting, representatives of RLF explained the duties of the EnLink Conflicts Committee in connection with the proposed transaction, provided an update on a proposed plan for negotiating the Merger Agreement, discussed legal implications of the GIP Offer Letters, and discussed legal matters and process issues relating to the potential transaction. Representatives of Evercore presented their preliminary financial analysis with respect to the proposed transaction. During its presentation, Evercore, among other things, reviewed the terms of the Initial ONEOK Offer, the capital structure of EnLink, historical trading prices of the EnLink Units and ONEOK Common Stock and Evercore’s diligence with management of EnLink and ONEOK, including EnLink’s financial forecasts and management’s responses to Evercore’s diligence questions. Evercore then presented its preliminary valuation of the EnLink Units. Following discussion, the EnLink Conflicts Committee directed Evercore to, on behalf of the EnLink Conflicts Committee, contact ONEOK and propose an exchange ratio implying that EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $18.25 per EnLink Unit and that the proposed transaction be conditioned upon receiving (i) a support agreement from ONEOK, and (ii) the approval of holders of a majority of the EnLink Units held by the EnLink Unaffiliated Unitholders (a “Majority of the Minority” and such counterproposal, the “First EnLink Counterproposal”).

On November 8, 2024, representatives of Evercore communicated the First EnLink Counterproposal to Mr. Hulse. On the same day, Mr. Hulse contacted Evercore and rejected the First EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.25 per EnLink Unit and noted that ONEOK would agree to provide a Support Agreement in connection with the proposed transaction (the “Second ONEOK Offer”). As part of the Second ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 11, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reported on the Second ONEOK Offer and presented Evercore’s revised financial analysis of the proposed transaction and the Second ONEOK Offer. The EnLink Conflicts Committee determined not to make a counteroffer at the meeting, and instructed Evercore to conduct additional diligence regarding EnLink’s business opportunities and growth projects with management of EnLink.

On November 12, 2024, representatives of Evercore met with EnLink management to discuss EnLink’s business opportunities and growth projects.

On November 12, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Second ONEOK Offer and discussed Evercore’s conversation with management of EnLink regarding EnLink’s business opportunities and growth projects. The EnLink Conflicts Committee and its advisors then discussed the Second ONEOK Offer and potential responses thereto. Following the discussion, the EnLink Conflicts Committee determined to propose that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $17.00 per EnLink Unit and that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority (the “Second EnLink Counterproposal”). The EnLink Conflicts Committee instructed Evercore to, on behalf of the EnLink Conflicts Committee, communicate the Second EnLink Counterproposal to Mr. Hulse.

Later on November 12, 2024, representatives of Evercore communicated the Second EnLink Counterproposal to Mr. Hulse. Mr. Hulse rejected the Second EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.50 per EnLink Unit (the “Third ONEOK Offer”). As part of the Third ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 15, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Third ONEOK Offer. Following the discussion, the EnLink Conflicts Committee discussed proposing that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of at least a minimum of $16.75 per EnLink Unit and that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority (the “Third EnLink Counterproposal”). Further, during this meeting, representatives of RLF described to the EnLink Conflicts Committee the material terms of the initial draft of the Merger Agreement provided by K&E, the draft of Support Agreement provided by Baker Botts, and potential revisions to both the draft Merger Agreement and Support Agreement. Following discussion, the EnLink Conflicts Committee determined not to provide comments to the initial draft of the Merger Agreement or circulate the Support Agreement to K&E at that time.

On November 17, 2024, the EnLink Conflicts Committee instructed Evercore to, on behalf of the EnLink Conflicts Committee, communicate the Third EnLink Counterproposal to Mr. Hulse the following day.

On November 18, 2024, representatives of Evercore communicated the Third EnLink Counterproposal to Mr. Hulse. On the same day, Mr. Hulse contacted Evercore and rejected the Third EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.60 per EnLink Unit (the “Fourth ONEOK Offer”). As part of the Fourth ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 20, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Fourth ONEOK Offer. During its presentation, Evercore reviewed, among other things, ONEOK’s recent stock price appreciation. The EnLink Conflicts Committee determined not to make a counteroffer at the meeting but instructed Evercore to contact Mr. Hulse to reiterate the EnLink’s Conflicts Committee’s views as to the value of the EnLink Units.

On November 21, 2024, prior to representatives of Evercore contacting Mr. Hulse, Mr. Hulse contacted Evercore and suggested, contingent upon ONEOK Board approval, that the exchange ratio to be used in the proposed transaction be determined by dividing $15.75 (as the proposed value for the EnLink Units) by ONEOK’s 5-day volume-weighted average price (the “Fifth ONEOK Offer”). As part of the Fifth ONEOK Offer, ONEOK also clarified that the proposed transaction would not be conditioned upon receiving the approval of a Majority of the Minority.

Later on November 21, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reported the terms of the Fifth ONEOK Offer to the EnLink Conflicts Committee, noting that the Fifth ONEOK Offer implied a $16.45 per EnLink Unit price based on ONEOK’s closing price on November 20, 2024. The representatives of Evercore presented their updated financial analysis of the proposed transaction and the Fifth ONEOK Offer. Following discussion of potential counteroffers to the Fifth ONEOK Offer, the EnLink Conflicts Committee directed Evercore to, on behalf of the EnLink Conflicts Committee, contact ONEOK and propose an exchange ratio be determined by dividing $15.75 (as the proposed value for the EnLink Units) by ONEOK’s 10-day volume-weighted average price (the “Final EnLink Counterproposal”). The EnLink Conflicts Committee further directed Evercore to, on behalf of the EnLink Conflicts Committee, inform ONEOK that the Final EnLink Counterproposal would not be conditioned upon the proposed transaction receiving the approval of a Majority of the Minority so long as ONEOK would agree to use ONEOK’s 10-day volume-weighted average price. Representatives of RLF then described to the EnLink Conflicts Committee proposed revisions to the initial draft of the Merger Agreement, including, among other things, the addition of (i) an ability for the EnLink’s Conflicts Committee to change its recommendation to the EnLink Unaffiliated Unitholders if it determines that the Mergers are no longer in the best interest of the EnLink Unaffiliated Unitholders irrespective of whether an intervening event had occurred; (ii) a mutual expense reimbursement provision payable upon termination of the Merger Agreement following a breach by the other party; (iii) a requirement that, if EnLink pays a distribution for any quarter, such distribution will be no less than $0.1325 per EnLink Unit; and (iv) a requirement that the EnLink Conflicts Committee approve any amendments or waivers to the Merger Agreement. Following such discussion, the EnLink’s Conflicts Committee instructed RLF to finalize the comments to the draft Merger Agreement and draft Support Agreement, and to send the documents to K&E.

Later on November 21, 2024, representatives of Evercore communicated the Final EnLink Counterproposal to Mr. Hulse, and RLF and Baker Botts provided comments to the draft Merger Agreement and an initial draft Support Agreement to K&E. Mr. Hulse informed Evercore that ONEOK would consider the Final EnLink Counterproposal and ONEOK would provide a response on November 22, 2024.

On November 22, 2024, Mr. Hulse contacted Evercore and accepted the Final EnLink Counterproposal, contingent upon ONEOK Board approval and negotiation of terms of the definitive Merger Agreement. On November 22, 2024, Baker Botts sent an initial draft of the EnLink disclosure schedule to K&E.

On November 22, 2024, K&E sent a revised draft of the Merger Agreement to RLF and Baker Botts. The revised draft Merger Agreement, among other things, (a) removed a provision allowing the EnLink Conflicts Committee to make an adverse recommendation change in the event that the EnLink Conflicts Committee determines that the failure to do so would be in the best interest of the EnLink Unaffiliated Unitholders; (b) reinstated a requirement that an adverse recommendation change required the occurrence of an intervening event; (c) removed certain interim operating covenants applicable to ONEOK; (d) proposed that the termination fee payable by EnLink in the event that the Merger Agreement is terminated following an adverse recommendation change by the EnLink Conflicts Committee be an amount equal to 2.5% of EnLink’s equity value; (e) proposed that the mutual expense reimbursement provisions payable by either EnLink or ONEOK in the event that the Merger Agreement is terminated following a material breach by the other party be up to an amount equal to 1.0% of EnLink’s equity value; and (f) otherwise accepted almost all other revisions that the EnLink Conflicts Committee had proposed to the initial draft of the Merger Agreement that K&E had prepared.

On November 23, 2024, representatives of Baker Botts and RLF had a call with EnLink management to discuss the revised draft of the Merger Agreement. Later on November 23, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reviewed the terms of the proposed transaction with the EnLink Conflicts Committee, noting that the exchange ratio created by ONEOK’s 10-day volume-weighted average price based on ONEOK’s closing price on November 22, 2024 was 0.1412 shares of ONEOK Common Stock for each EnLink Unit, which implied a $16.53 per EnLink Unit price based on ONEOK’s November 22, 2024 closing price. During the meeting, RLF described to the EnLink Conflicts Committee the open issues in the draft of the Merger Agreement and a draft of the joint press release to be issued in connection with the proposed transaction.

On November 23, 2024 and November 24, 2024, representatives of K&E, RLF and Baker Botts exchanged additional comments to the draft Merger Agreement, the EnLink disclosure schedules and the Support Agreement. As a result of these exchanges, the Merger Agreement (i) retained a provision allowing the EnLink Conflicts

Committee to make an adverse recommendation change in the event that the EnLink Conflicts Committee determines in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law; (ii) provided for a termination fee payable by EnLink in the event that the Merger Agreement is terminated following an adverse recommendation change by the EnLink Conflicts Committee in an amount equal to 2.0% of EnLink’s equity value; and (iii) provided for a mutual expense reimbursement in an amount up to $10 million payable by either EnLink or ONEOK in the event that the Merger Agreement is terminated following a material breach by the other party.

On November 24, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, the EnLink Conflicts Committee and its advisors discussed the proposed transaction, including the terms and conditions of the Merger Agreement, and RLF presented to the EnLink Conflicts Committee an overview and update with respect to the terms of the Merger Agreement. Also at this meeting, Evercore reviewed its updated financial analysis of the proposed transaction with the EnLink Conflicts Committee and, at the request of the EnLink Conflicts Committee, rendered an oral opinion to the EnLink Conflicts Committee, which was subsequently confirmed by delivery of a written opinion dated November 24, 2024, to the effect that, as of the date of such opinion and subject to the factors, procedures, assumptions, qualifications and limitations set forth therein, the Exchange Ratio is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders. At this meeting, the EnLink Conflicts Committee unanimously (i) determined that the proposed Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders; (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended that (A) the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the holders of the EnLink Units and (B) the holders of the EnLink Units approve the Merger Agreement and the Mergers.

Further, on November 24, 2024, following the receipt of the recommendation of the EnLink Conflicts Committee, the EnLink Board, by unanimous approval, (i) determined that the proposed transaction, on the terms and conditions sets forth in the Merger Agreement and the Support Agreement, is in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (iv) resolved to recommend that the EnLink unitholders approve the Merger Agreement.

Subsequently on November 24, 2024, (i) EnLink, the Manager, ONEOK, Merger Sub I and Merger Sub II executed and delivered the Merger Agreement and (ii) ONEOK and EnLink executed and delivered the Support Agreement.

On November 24, 2024, ONEOK and EnLink issued a joint press release announcing the execution of the Merger Agreement.

On November 25, 2024, each of ONEOK and EnLink filed a Current Report on Form 8-K with respect to the Merger Agreement and Support Agreement, and attaching the joint press release and an employee communication.

Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers

The EnLink Board directed the EnLink Conflicts Committee, comprised solely of three independent directors, Ms. Cepak, Ms. Adams and Mr. Echols, who meet the requirements for membership on the EnLink Conflicts Committee set forth in the EnLink Operating Agreement, (i) to make an investigation of the potential transaction and the alternative of maintaining the status quo, as the EnLink Conflicts Committee deems necessary or appropriate, (ii) to review, evaluate, and negotiate (or to supervise and direct the negotiations on behalf of EnLink with respect to) the terms and conditions, and determine the advisability, of the potential transaction and related agreements and arrangements, (iii) to determine whether the potential transaction is in, or not opposed to,

the best interests of EnLink, (iv) to determine whether to approve the potential transaction (with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof), and to make a recommendation to the EnLink Board whether to approve the potential transaction and, if appropriate, to recommend that the EnLink unitholders approve the potential transaction, it being understood that any potential transaction is subject to (A) the receipt of a proposal from ONEOK and (B) the approval of the EnLink Board and, in accordance with Section 5.6(b) of the Second Amended and Restated Limited Liability Company Agreement of EnLink Midstream Manager, LLC, dated as of July 18, 2018 (as amended or supplemented, the “Manager LLCA”), ONEOK, in its capacity as sole member of the Manager of the potential transaction, and (v) to make any other recommendations to the EnLink Board and/or the EnLink unitholders regarding the potential transaction as the EnLink Conflicts Committee shall determine to be appropriate. The EnLink Conflicts Committee retained Richards, Layton & Finger, P.A. (“RLF”) as its legal counsel, and Evercore as its financial advisor. The EnLink Conflicts Committee oversaw the performance of financial, legal and other due diligence by its advisors, conducted an extensive review and evaluation of the potential transaction and conducted negotiations with ONEOK and its representatives with respect to the Merger Agreement and the Support Agreement and the transactions contemplated thereby.

On November 24, 2024, the EnLink Conflicts Committee considered the benefits of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, as well as the associated risks, and unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

The EnLink Conflicts Committee considered the following factors, the order of which does not necessarily reflect their relative significance, to be generally positive or favorable to EnLink and the EnLink Unaffiliated Unitholders in making its determination and approvals and the related recommendation to the EnLink Board:

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each EnLink Unit represents an implied value for the EnLink Units of $16.53 per EnLink Unit, which was an implied 25.6% premium to the value of the EnLink Units based upon the closing price of EnLink Units on August 28, 2024 (the unaffected trading price prior to ONEOK’s public announcement of the GIP Interest Acquisition and its intention to pursue a buy-in transaction).

•        The EnLink Conflicts Committee’s belief that the exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders provides greater value to the EnLink Unaffiliated Unitholders than the long-term value of EnLink as a standalone publicly traded company, after taking into account, among other things, EnLink’s future growth prospects following ONEOK’s purchase of the managing member interest of EnLink.

•        The ONEOK Common Stock that EnLink Unaffiliated Unitholders will receive in the Mergers is more liquid than EnLink Units based on the larger daily trading volume of shares of ONEOK Common Stock, which was trading approximately 10x the dollar volume of EnLink Units on a daily basis as of the time of the EnLink Conflicts Committee’s approval, ONEOK’s broader investor base, and the larger public float of shares of ONEOK Common Stock.

•        The Mergers will result in EnLink Unaffiliated Unitholders becoming equity owners in a combined business with more diversified assets, an investment grade credit rating and more growth opportunities than EnLink on a standalone basis.

•        The holders of shares of ONEOK Common Stock (and the EnLink Unaffiliated Unitholders as a result of receiving shares of ONEOK Common Stock in the First Merger) will benefit from synergies, including reduced SEC filing requirements and a reduction in the number of public company boards.

•        The potential transaction is expected to be immediately accretive to the EnLink Unaffiliated Unitholders with regard to dividends per share of ONEOK Common Stock pro forma for the Mergers versus distributions per EnLink Unit on a standalone basis.

•        The potential transaction is expected generally to be non-taxable to the EnLink Unaffiliated Unitholders.

•        The financial analyses prepared by Evercore during the course of the deliberations and negotiations and the oral opinion of Evercore rendered to the EnLink Conflicts Committee on November 24, 2024 (which was subsequently confirmed in writing by delivery of Evercore’s written opinion addressed to the EnLink Conflicts Committee dated November 24, 2024), to the effect that, as of the date of such opinion, and based upon and subject to the assumptions, limitations, qualifications, and conditions described in Evercore’s written opinion, the exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit to be received in the First Merger is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders.

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders is fixed and therefore the implied value of the consideration payable to the EnLink Unaffiliated Unitholders will increase in the event that the market price of ONEOK stock increases prior to the closing of the Mergers.

•        The terms and conditions of the Merger Agreement, which were determined through arm’s-length negotiations between the EnLink Conflicts Committee and ONEOK and their respective representatives and advisors.

•        The negotiated terms of the Merger Agreement, principally:

•        Provisions permitting the EnLink Conflicts Committee to change or withdraw its recommendation to the EnLink unitholders in favor of the Mergers if the EnLink Conflicts Committee determines in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law.

•        Provisions restricting any elimination of the EnLink Conflicts Committee, revocation or diminution of the authority of the EnLink Conflicts Committee and removal of the members of the EnLink Conflicts Committee between signing of the Merger Agreement and closing of the Mergers.

•        Provisions obligating ONEOK to pay the reasonably documented out-of-pocket expenses incurred by EnLink and its affiliates in connection with the Mergers up to a maximum amount of $10.0 million if the Merger Agreement is terminated under certain circumstances.

•        Provisions restricting amendment of the Merger Agreement without the approval of the EnLink Conflicts Committee.

•        The agreement by ONEOK to vote its EnLink Units in favor of the Merger Agreement and the transactions contemplated thereby.

•        The Mergers are not subject to a vote of ONEOK’s stockholders.

•        ONEOK is governed with a C-corporation structure that will provide governance protections and shareholder rights for the EnLink Unaffiliated Unitholders, which they do not have today.

•        Financial and legal advice provided to the EnLink Conflicts Committee during its deliberations and the negotiation of the Mergers, and the EnLink Conflicts Committee’s engagement of financial and legal advisors with knowledge and experience with respect to public merger and acquisition transactions, EnLink’s industry generally, and EnLink in particular, as well as substantial experience advising companies with respect to transactions similar to the Mergers.

The EnLink Conflicts Committee considered the following factors, the order of which does not necessarily reflect their relative significance, to be potentially negative or unfavorable in arriving at its determination and approvals, and the related recommendation to the EnLink Board:

•        The EnLink Conflicts Committee was not authorized to and did not conduct an auction process or other solicitation of interest from third parties for the acquisition of EnLink Units. Since ONEOK indirectly controls EnLink, it was unrealistic to expect an unsolicited third-party acquisition proposal to acquire assets or control of EnLink, and it was unlikely that the EnLink Conflicts Committee could conduct a meaningful process to solicit interest in the acquisition of assets or control of EnLink.

•        EnLink Unaffiliated Unitholders will be foregoing the potential benefits, if any, that could be realized by EnLink on a standalone basis.

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders is fixed and therefore the implied value of the consideration payable to the holders of EnLink Unaffiliated Units will decrease in the event that the market price of ONEOK stock decreases prior to the closing of the Mergers.

•        The vote required to approve the Mergers, which is not subject to approval by majority vote of the EnLink Unaffiliated Unitholders.

•        Even if the EnLink Conflicts Committee were to withdraw or change its recommendation to the EnLink unitholders regarding the Mergers, EnLink would still be required to call a unitholder meeting to vote on the approval of the Mergers and ONEOK owns approximately 44% of the outstanding EnLink Units.

•        Certain terms of the Merger Agreement, principally:

•        Provisions obligating EnLink to pay a termination fee to ONEOK equal to $143,978,000 if the Merger Agreement is terminated under certain circumstances.

•        Provisions obligating EnLink to pay the reasonably documented out-of-pocket expenses incurred by ONEOK and its affiliates in connection with the Mergers up to a maximum amount of $10.0 million if the Merger Agreement is terminated under certain circumstances.

•        Provisions restricting the conduct of EnLink’s business during the interim period between signing of the Merger Agreement and closing of the Mergers.

•        Relatively limited interim operating covenants restricting the operation of ONEOK’s business during the period between signing of the Merger Agreement and closing of the Mergers.

•        Potential risks or delay in consummating the Mergers, meaning there can be no assurance that all conditions to the parties’ obligations to complete the Mergers will be satisfied, and thus it is possible that the Mergers may not be completed in a timely manner or at all.

•        Potential risks if the Mergers are not completed, with potential disruption to the business of EnLink and a potential decline in the trading price of EnLink Units.

•        The risk that litigation may occur in connection with the Mergers, and that any such litigation may result in delay, significant costs and a diversion of management’s focus on the conduct of the business of EnLink.

•        EnLink has incurred and will continue to incur transaction costs and expenses in connection with the Mergers, whether or not the Mergers are completed.

•        EnLink and some of the executive officers and directors of the EnLink Board have interests in the Mergers that are different from, or in addition to, the interests of the EnLink Unaffiliated Unitholders generally.

The foregoing discussion of the information and factors considered by the EnLink Conflicts Committee is not intended to be exhaustive, but includes material factors the EnLink Conflicts Committee and the EnLink Board considered. In view of the variety of factors considered in connection with its evaluation of the Mergers and the complexity of these matters, the EnLink Conflicts Committee and EnLink Board did not find it useful and did not attempt to quantify or assign any relative or specific weights to the various factors considered in making its determination and recommendation. In addition, each of the members of the EnLink Conflicts Committee or the EnLink Board may have given differing weights to different factors. Overall, the EnLink Conflicts Committee and the EnLink Board believed that the positive factors supporting the Merger outweighed the negative factors it considered.

Certain Unaudited Forecasted Financial Information of EnLink

Neither ONEOK nor EnLink, as a matter of course, makes public long-term forecasts or internal projections as to future performance, revenues, production, earnings or other results due to, among other reasons, the uncertainty of the underlying assumptions and estimates. However, in connection with EnLink’s evaluation of the Mergers, EnLink’s management provided to the EnLink Board, ONEOK and the EnLink Conflicts Committee’s financial advisor certain unaudited internal financial forecasts with respect to EnLink on a stand-alone basis prepared by EnLink’s management (the “EnLink Forecasted Financial Information”). The EnLink Forecasted Financial Information was provided by EnLink to Evercore for its use and reliance in connection with its financial analyses and opinion as described in the section entitled “The Mergers — Opinion of EnLink Conflicts Committee’s Financial Advisor.” The inclusion of this EnLink Forecasted Financial Information should not be regarded as an indication that any of EnLink, ONEOK, their respective affiliates, officers, directors, advisors or other representatives or any other recipient of this EnLink Forecasted Financial Information considered, or now considers, it to be necessarily predictive of actual future performance or events, or that it should be construed as financial guidance, and such projections set forth below should not be relied on as such.

The EnLink Forecasted Financial Information includes non-GAAP financial measures, including Adjusted EBITDA, Net Operating Income, Distributable Cash Flow, and Free Cash Flow After Distributions. Please see the tables below for a description of how EnLink defines these non-GAAP financial measures. EnLink believes that Adjusted EBITDA provides information useful in assessing operating and financial performance across periods, while Net Operating Income, Distributable Free Cash Flow and Free Cash Flow After Distributions each provides a useful measure of available cash generated by operating activities for other investing and financing activities. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information presented in accordance with GAAP, and non-GAAP financial measures used by EnLink may not be comparable to similarly titled measures used by other companies.

This EnLink Forecasted Financial Information was prepared solely for internal use and is subjective in many respects. While presented with numeric specificity, the EnLink Forecasted Financial Information reflects numerous estimates and assumptions that are inherently uncertain and may be beyond the control of EnLink’s and ONEOK’s managements, including, among others, future results of EnLink, oil and gas industry activity, commodity prices, demand for natural gas and crude oil, general economic and regulatory conditions and other matters described in the sections entitled “Cautionary Statement Regarding Forward-Looking Statements” and “Risk Factors.” The EnLink Forecasted Financial Information reflects both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. Neither EnLink, ONEOK, nor their respective affiliates, officers, directors, advisors or other representatives can give assurance that the EnLink Forecasted Financial Information and the underlying estimates and assumptions will be realized. This EnLink Forecasted Financial Information constitutes “forward-looking statements” and actual results may differ materially and adversely from those set forth below.

The EnLink Forecasted Financial Information was not prepared with a view toward compliance with published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation or presentation of prospective financial information. The EnLink Forecasted Financial Information included in this proxy statement/prospectus has been prepared by, and is the responsibility of, management of EnLink. Neither KPMG LLP nor PricewaterhouseCoopers LLP has audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying EnLink Forecasted Financial Information and,

accordingly, neither KPMG LLP nor PricewaterhouseCoopers LLP expresses an opinion or any other form of assurance with respect thereto. The report of KPMG LLP contained in EnLink’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of EnLink, and such report does not extend to the EnLink Forecasted Financial Information and should not be read to do so. In addition, the PricewaterhouseCoopers LLP report contained in ONEOK’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference in this proxy statement/prospectus, relates to ONEOK’s previously issued financial statements. Such report does not extend to the EnLink Forecasted Financial Information and should not be read to do so.

The EnLink Forecasted Financial Information does not take into account any circumstances or events occurring after the date it was prepared. Neither EnLink nor ONEOK can give assurance that, had the EnLink Forecasted Financial Information been prepared either as of the date of the Merger Agreement or as of the date of this proxy statement/prospectus, similar estimates and assumptions would be used. Except as required by applicable securities laws, EnLink and ONEOK do not intend to, and disclaim any obligation to, make publicly available any update or other revision to the EnLink Forecasted Financial Information to reflect circumstances existing since their preparation or to reflect the occurrence of unanticipated events, even if any or all of the underlying assumptions are shown to be inappropriate, including with respect to the accounting treatment of the Mergers under GAAP, or to reflect changes in general economic or industry conditions. The EnLink Forecasted Financial Information does not take into account all of the possible financial and other effects of the Mergers on EnLink, the effect on EnLink of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed, or the effect of any business or strategic decisions or actions that would likely have been taken if the Merger Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Mergers. Further, the EnLink Forecasted Financial Information does not take into account the effect on EnLink of any possible failure of the Mergers to occur. None of EnLink or ONEOK or their respective affiliates, officers, directors, advisors or other representatives has made, makes or is authorized in the future to make any representation to any EnLink unitholder or ONEOK shareholder or other person regarding EnLink’s ultimate performance compared to the information contained in the EnLink Forecasted Financial Information or that the EnLink Forecasted Financial Information will be achieved. The inclusion of the EnLink Forecasted Financial Information herein should not be deemed an admission or representation by any of EnLink, ONEOK, their respective affiliates, officers, directors, advisors or other representatives or any other person that it is viewed as material information of EnLink or ONEOK, particularly in light of the inherent risks and uncertainties associated with such forecasts. The EnLink Forecasted Financial Information included below is not being included in this proxy statement/prospectus in order to influence any EnLink unitholder’s decision or to induce any unitholder to vote in favor of any of the proposals at the EnLink Special Meeting, but is being provided solely because it was made available to the EnLink Board, the EnLink Conflicts Committee, the EnLink Conflicts Committee’s financial advisor and the ONEOK Board, as applicable, in connection with the Mergers.

In light of the foregoing, and considering that the EnLink Special Meeting will be held several months after the EnLink Forecasted Financial Information was prepared, as well as the uncertainties inherent in any forecasted information, EnLink unitholders are cautioned not to place undue reliance on such information, and each of EnLink and ONEOK urges you to review EnLink’s and ONEOK’s most recent SEC filings for a description of EnLink’s and ONEOK’s reported financial results included therein. Please see “Where You Can Find More Information.”

The following table sets forth certain prospective financial and operating information regarding EnLink for the fiscal years 2024 through 2028 on a stand-alone basis prepared by EnLink management.

____________

(1)      The EnLink Forecasted Financial Information set forth in this table does not take into account any circumstances or events occurring after the date it was prepared. Given that the EnLink Special Meeting will be held several months after the EnLink Forecasted Financial Information was prepared, as well as the uncertainties inherent in any forecasted information, EnLink unitholders and ONEOK shareholders are cautioned not to place undue reliance on such information.

(2)      Net operating income is defined as revenue less cost of sales, operating expenses and the relocation of processing facilities.

(3)      Adjusted EBITDA is defined as net income (loss) plus (less) interest expense, net of interest income; depreciation and amortization; impairments; (income) loss from unconsolidated affiliate investments; distributions from unconsolidated affiliate investments; (gain) loss on disposition of assets; (gain) loss on extinguishment of debt; (gain) loss on litigation settlement; unit-based compensation; income tax expense (benefit); unrealized (gain) loss on commodity derivatives; costs associated with the relocation of processing facilities; accretion expense associated with asset retirement obligations; transaction costs; non-cash expense related to changes in the fair value of contingent consideration; (non-cash rent); and (non-controlling interest share of adjusted EBITDA from joint ventures).

(4)      Distributable cash flow is defined as adjusted EBITDA, net to EnLink, plus (less) (interest expense, net of interest income); (maintenance capital expenditures, excluding maintenance capital expenditures that were contributed by other entities and relate to the non-controlling interest share of our consolidated entities); (accrued cash distributions on ENLK Series B Units paid or expected to be paid); (payments to terminate interest rate swaps); non-cash interest (income)/expense; and (current income taxes).

(5)      Free cash flow after distributions is defined as adjusted EBITDA, net to EnLink, plus (less) (growth and maintenance capital expenditures, excluding capital expenditures that were contributed by other entities and relate to the non-controlling interest share of our consolidated entities); (interest expense, net of interest income); (distributions declared on common units); (cash distributions earned by the ENLK Series B Units); (payment to redeem mandatorily redeemable non-controlling interest); (costs associated with the relocation of processing facilities, excluding costs that were contributed by other entities and relate to the non-controlling interest share of our consolidated entities); non-cash interest (income)/expense; (contributions to investment in unconsolidated affiliates); (payments to terminate interest rate swaps); (current income taxes); earnout payments related to certain acquisitions; (non-cash gain associated with a lease modification); and proceeds from the sale of equipment and land.

ONEOK and EnLink do not intend to update or otherwise revise the above EnLink Forecasted Financial Information to reflect circumstances existing after the date when made or to reflect the occurrence of future events, even in the event that any or all of the assumptions underlying such EnLink Forecasted Financial Information are no longer appropriate, except as may be required by applicable law.

Opinion of EnLink Conflicts Committee’s Financial Advisor

Evercore was retained by the EnLink Conflicts Committee to act as its financial advisor in connection with evaluating the proposed Mergers. On November 24, 2024, at a meeting of the EnLink Conflicts Committee and at the request of the EnLink Conflicts Committee, Evercore rendered its oral opinion to the EnLink Conflicts Committee to the effect that, as of November 24, 2024 and based upon and subject to the assumptions, qualifications, limitations and other matters set forth in its opinion, the Exchange Ratio is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders. Evercore subsequently confirmed its oral opinion in a written opinion dated November 24, 2024.

The full text of the Evercore’s written opinion of Evercore to the EnLink Conflicts Committee, dated as of November 24, 2024, which sets forth, among other things, the assumptions made, procedures followed, assumptions made, matters considered and qualifications and limitations on the scope of the review undertaken by Evercore in rendering its opinion, is attached hereto as Annex B to this proxy statement/prospectus and is incorporated herein by reference. The foregoing summary of Evercore’s opinion is qualified in its entirety by reference to the full text of the opinion included as Annex B. You are urged to read Evercore’s opinion and the summary of Evercore’s opinion below carefully and in their entirety. Evercore’s opinion was addressed to, and provided for the information and benefit of, the EnLink Conflicts Committee in connection with its evaluation of the fairness of the Exchange Ratio, from a financial point of view, to the EnLink Unaffiliated Unitholders, and did not address any other aspects or implications of the Mergers. Evercore’s opinion should not be construed as creating any fiduciary duty on Evercore’s part to any party and such opinion was not intended to be, and does not constitute, a recommendation to the EnLink Conflicts Committee or to any other persons in respect of the Mergers, including as to how the EnLink Unaffiliated Unitholders should act or vote in respect of the Mergers. The summary of the Evercore opinion set forth herein is qualified in its entirety by reference to the full text of the opinion included as Annex B.

In connection with rendering its opinion and performing its related financial analysis, Evercore, among other things:

•        reviewed certain publicly available business and financial information relating to EnLink and ONEOK that Evercore deemed to be relevant, including publicly available research analysts’ estimates;

•        reviewed certain internal projected financial data relating to EnLink and furnished to Evercore by the management of EnLink, as approved for Evercore’s use by the EnLink Conflicts Committee (the “Forecasts”);

•        discussed with management of EnLink their assessment of the past and current operations of EnLink, the current financial condition and prospects of EnLink and the Forecasts relating to EnLink;

•        discussed with management of ONEOK their assessment of the past and current operations of ONEOK, the current financial condition and prospects of ONEOK and research analysts’ estimated projected financial data as representative of such prospects, as directed by ONEOK and approved for Evercore’s use by the EnLink Conflicts Committee;

•        reviewed the reported prices and the historical trading activity of the EnLink Units and ONEOK Common Stock;

•        performed discounted cash flow analyses of EnLink based on the Forecasts, and performed discounted cash flow analyses of ONEOK Common Stock based on research analysts’ estimated projected financial data, as directed and approved for Evercore’s use by the EnLink Conflicts Committee;

•        performed discounted distributions analyses on EnLink based on the Forecasts, and performed discounted dividend analyses on ONEOK based on research analysts’ estimated projected financial data, as directed and approved for Evercore’s use by the EnLink Conflicts Committee;

•        compared the financial performance of EnLink and ONEOK and their respective stock market trading multiples with those of certain other publicly traded companies and partnerships that Evercore deemed relevant;

•        compared the reported prices and historical trading activities of the EnLink Units with those of publicly traded equity securities of certain other publicly traded companies and partnerships that Evercore deemed relevant;

•        compared the reported prices and historical trading activities of ONEOK Common Stock with those of publicly traded equity securities of certain other publicly traded companies that Evercore deemed relevant;

•        compared the financial performance of EnLink and the valuation multiples relating to the First Merger with the financial terms, to the extent publicly available, of certain other transactions that Evercore deemed relevant;

•        reviewed the financial terms and conditions of the Merger Agreement; and

•        performed such other analyses and examinations and considered such other factors that Evercore deemed appropriate.

For purposes of its analysis and opinion, Evercore assumed and relied upon the accuracy and completeness of the financial and other information publicly available, and all of the information supplied or otherwise made available to, discussed with, or reviewed by Evercore, without any independent verification of such information (and has not assumed responsibility or liability for any independent verification of such information), and has further relied upon the assurances of the managements of ONEOK and EnLink that they are not aware of any facts or circumstances that would make such information inaccurate or misleading. With respect to the Forecasts, Evercore had assumed with the EnLink Conflicts Committee’s consent that such data has been reasonably prepared on bases reflecting the best currently available estimates and good faith judgments of the management of EnLink as to the future financial performance of EnLink. Evercore did not express a view as to the Forecasts or the assumptions on which they are based.

For purposes of Evercore’s analysis and opinion, Evercore assumed, in all respects material to its analysis, that the final executed Merger Agreement would not differ from the draft Merger Agreement reviewed by Evercore, that the representations and warranties of each party contained in the Merger Agreement are true and correct, that each party will perform all of the covenants and agreements required to be performed by it under the Merger Agreement and that all conditions to the consummation of the Mergers will be satisfied without waiver or modification thereof. Evercore had further assumed, in all respects material to its analysis, that all governmental, regulatory or other

consents, approvals or releases necessary for the consummation of the Mergers would be obtained without any delay, limitation, restriction or condition that would have an adverse effect on EnLink, ONEOK or the consummation of the Mergers or reduce the contemplated benefits of the Mergers to the EnLink Unaffiliated Unitholders.

Evercore did not conduct a physical inspection of the properties or facilities of EnLink or ONEOK and did not make or assume any responsibility for making any independent valuation or appraisal of the assets or liabilities (including any contingent, derivative or other off balance sheet assets and liabilities) of EnLink or ONEOK, nor has Evercore been furnished with any such valuations or appraisals, nor did Evercore evaluate the solvency or fair value of EnLink or ONEOK under any state or federal laws relating to bankruptcy, insolvency or similar matters. Evercore’s opinion was necessarily based upon information made available to Evercore as of the date of its opinion and financial, economic, monetary, market, regulatory and other conditions and circumstances as they exist and as could be evaluated on the date of its opinion. It is understood that subsequent developments may affect Evercore’s opinion and that Evercore does not have any obligation to update, revise or reaffirm its opinion.

Evercore was not asked to pass upon, and did not express an opinion with respect to, any matter other than the fairness to the EnLink Unaffiliated Unitholders, from a financial point of view, of the Exchange Ratio, as of the date of its opinion. Evercore did not express any view on, and its opinion did not address, the fairness of the Mergers to, or any consideration received in connection therewith by, the holders of any other securities, creditors or other constituencies of EnLink or any other party to the Merger Agreement or any affiliates thereof, nor as to the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of EnLink or any other party to the Merger Agreement or any affiliates thereof, or any class of such persons, whether relative to the Exchange Ratio or otherwise. Evercore was not asked to, nor did it express any view on, and its opinion did not address, any other term or aspect of the Merger Agreement or the Mergers, including, without limitation, the structure or form of the Mergers, or any term or aspect of any other agreement or instrument contemplated by the Merger Agreement or entered into or amended in connection with the Merger Agreement. Evercore’s opinion did not address the relative merits of the Mergers as compared to other business or financial strategies that might be available to EnLink, nor did it address the underlying business decision of EnLink to engage in the Mergers. Evercore did not express any view on, and its opinion did not address, what the value of ONEOK Common Stock actually will be when issued or the prices at which ONEOK Common Stock will trade at any time, including following announcement or consummation of the Mergers. Evercore’s opinion did not constitute a recommendation to the EnLink Conflicts Committee or to any other persons in respect of the Mergers, including as to how any holder of the EnLink Units should vote or act in respect of the Mergers. Evercore expressed no opinion as to the price at which the EnLink Units will trade at any time, as to the potential effects of volatility in the credit, financial and stock markets on EnLink or the Mergers or as to the impact of the Mergers on the solvency or viability of EnLink or the ability of EnLink to pay its obligations when they come due. Evercore is not a legal, regulatory, accounting or tax expert and has assumed the accuracy and completeness of assessments by ONEOK and its advisors with respect to legal, regulatory, accounting and tax matters.

Set forth below is a summary of the material financial analyses performed by Evercore and reviewed with the EnLink Conflicts Committee on November 24, 2024, in connection with rendering Evercore’s opinion to the EnLink Conflicts Committee. Each analysis was provided to the EnLink Conflicts Committee. The following summary, however, does not purport to be a complete description of the analyses performed by Evercore. In connection with arriving at its opinion, Evercore considered all of its analyses as a whole, and the order of the analyses described and the results of these analyses do not represent any relative importance or particular weight given to these analyses by Evercore. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data that existed on November 24, 2024, and is not necessarily indicative of current market conditions.

Throughout the “Analysis of EnLink” and the “Analysis of ONEOK” below, the term “EBITDA,” as used in connection with Evercore’s various financial analyses, means the relevant company’s estimated earnings before interest, taxes, depreciation and amortization. In the case of EnLink and ONEOK, the term “EBITDA” means adjusted EBITDA, as used by EnLink’s management and defined in the section entitled “Unaudited Financial Projections of EnLink.”

The following summary of financial analyses includes information presented in tabular format. These tables must be read together with the text of each summary in order to fully understand the financial analyses performed by Evercore. The tables alone do not constitute a complete description of the financial analyses

performed by Evercore. Considering the tables below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of Evercore’s financial analyses.

Analysis of EnLink

Assumptions with Respect to EnLink

Evercore performed a series of financial analyses to derive indicative valuation ranges for the EnLink Units. Financial data for EnLink utilized in the financial analyses described below were based upon, among other things, the unaudited, non-public financial projections for EnLink prepared and furnished by management of EnLink (the “EnLink Financial Projections”). A summary of the EnLink Financial Projections is available in the section entitled “The Mergers — Unaudited Financial Projections of EnLink.” The EnLink Financial Projections were not adjusted by Evercore.

Discounted Cash Flow Analysis

Evercore performed a discounted cash flow analysis of EnLink by valuing the cash flows to be received by EnLink based on the EnLink Financial Projections from 2025 through 2028. Evercore calculated the per unit value range for the EnLink Units by utilizing a range of discount rates based on EnLink’s Weighted Average Cost of Capital (“WACC”), as estimated by Evercore based on a theoretical Capital Asset Pricing Model (“CAPM”) and terminal values based on a range of estimated EBITDA multiples and perpetuity growth rates.

For EnLink’s discounted cash flow analysis, Evercore assumed a range of discount rates of 8.0% to 9.5% based on EnLink’s WACC, a range of EBITDA multiples of 8.5x to 11.0x applied to EnLink’s terminal period EBITDA and a range of perpetuity growth rates of -0.25% to 0.25% applied to EnLink’s terminal period cash flows based on the EnLink Financial Projections, as applicable, to derive a range of enterprise values. Evercore adjusted such enterprise values for projected debt, preferred equity and cash as of December 31, 2024, and divided the resulting equity values by the number of fully-diluted EnLink Units as of December 31, 2024. The discounted cash flow analysis utilizing the EBITDA multiple terminal value methodology resulted in an implied equity value per EnLink Unit range of $15.42 to $22.86. When assuming the closing share price of ONEOK Common Stock on November 22, 2024, this range implies exchange ratios of 0.1317x to 0.1953x, which compares to the Exchange Ratio of 0.1412x. The discounted cash flow analysis utilizing the perpetuity growth rate methodology to calculate terminal value resulted in an implied equity value per EnLink Unit range of $13.92 to $20.08. When assuming the closing share price of OKE on November 22, 2024, this range implies exchange ratios of 0.1189x to 0.1715x, which compares to the Exchange Ratio of 0.1412x.

Public Companies and Partnerships Trading Analysis

Evercore performed a public companies and partnerships trading analysis of EnLink by reviewing and comparing the market values and trading multiples of the following six publicly traded corporations and partnerships that Evercore deemed to have certain business characteristics that are similar to those of EnLink and five publicly traded partnerships that Evercore deemed to have certain business, legal and tax characteristics similar to those of EnLink:

Gathering and Processing Public Companies:

•        Antero Midstream Corporation

•        DT Midstream, Inc.

•        Hess Midstream LP

•        Kinetik Holdings Inc.

•        Targa Resources Corp.

•        Western Midstream Partners, LP

Master Limited Partnerships (“MLPs”):

•        Energy Transfer LP

•        Enterprise Products Partners L.P.

•        Hess Midstream LP

•        MPLX LP

•        Western Midstream Partners, LP

Although the gathering and processing public companies and MLPs were utilized to value the EnLink Units for purposes of this analysis, no corporation or partnership used in the analysis is identical or directly comparable to EnLink. In order to calculate trading multiples, Evercore relied on publicly available filings with the SEC and equity research analyst estimates.

For the gathering and processing public companies and MLPs trading analysis, Evercore calculated the following trading multiples:

•        Enterprise Value/2025 EBITDA, which is defined as market value of equity, plus preferred equity (as applicable), plus noncontrolling interest (as applicable), plus debt and less cash (“Enterprise Value”), divided by estimated EBITDA for the calendar year 2025.

•        Enterprise Value/2026E EBITDA, which is defined as Enterprise Value divided by estimated EBITDA for the calendar year 2026.

The mean and median Enterprise Value to EBITDA trading multiples of the gathering and processing public companies and MLPs are set forth below.

The table below includes relevant multiple ranges selected by Evercore and utilized in its analysis based on the resulting ranges of Enterprise Value to EBITDA multiples and certain other considerations related to the specific characteristics of EnLink noted by Evercore.

After adjusting for projected preferred equity, debt and cash as of December 31, 2024, and dividing by the number of fully-diluted EnLink Units as of December 31, 2024, Evercore determined an implied equity value per EnLink Unit range of $13.44 to $21.05 based on 2025 EBITDA from the EnLink Financial Projections and an implied equity value per EnLink Unit range of $13.64 to $21.78 based on 2026 EBITDA from the EnLink Financial Projections. When assuming the closing share price of ONEOK Common Stock on November 22, 2024, the 2025 EBITDA range implies exchange ratios of 0.1148x to 0.1798x and the 2026 EBITDA range implies exchange ratios of 0.1165x to 0.1861x, which compares to the Exchange Ratio of 0.1412x.

Precedent M&A Transaction Analysis

Evercore also performed a precedent M&A transaction analysis of the EnLink Units utilizing the EnLink Financial Projections by reviewing and comparing precedent M&A transactions that Evercore deemed to have similar characteristics to those of the Mergers.

Evercore reviewed transactions involving corporate midstream transactions announced since February 2021 and selected five transactions, although Evercore noted that none of the selected transactions were directly comparable to the Mergers and none of the entities that participated in the selected transactions were directly comparable to EnLink:

Evercore noted that the mean and median of the implied Enterprise Value to NTM EBITDA multiples for the selected corporate midstream transactions were 9.2x and 8.5x, respectively.

Based on Evercore’s review of the above precedent transactions, Evercore selected a range of relevant implied multiples of Enterprise Value to EBITDA of 8.0x to 10.0x. Evercore then applied the range of selected multiples to EnLink’s 2025E EBITDA and adjusted for projected preferred equity, debt and cash as of December 31, 2024, and then divided the result by the number of fully-diluted EnLink Units outstanding as of December 31, 2024 which resulted in an implied equity value per EnLink Unit range of $11.92 to $18.01. When assuming the closing share price of ONEOK Common Stock on November 22, 2024, this range implies exchange ratios of 0.1018x to 0.1538x, which compares to the Exchange Ratio of 0.1412x.

Discounted Distributions Analysis

Evercore performed a discounted distributions analysis by valuing the projected cash distributions of EnLink based on the EnLink Financial Projections from 2025 through 2028. Evercore discounted projected distributions using cost of equity discount rates of 10.0% to 12.0% based on CAPM as well as a terminal yield range of 3.0% to 4.5% based on EnLink’s trailing 52-week yield range. The analyses of the projected cash distributions resulted in an implied per EnLink Unit value range of $9.19 to $13.83 based on the EnLink Financial Projections. When assuming the closing share price of OKE on November 22, 2024, this range implies exchange ratios of 0.0785x to 0.1181x, which compares to the Exchange Ratio of 0.1412x.

Analysis of ONEOK

Assumptions with Respect to ONEOK

Evercore performed a series of analyses to derive indicative valuation ranges for ONEOK Common Stock. Evercore performed its analyses utilizing Wall Street Research which reflect input from ONEOK management (the “ONEOK Financial Projections”). No financial projections were provided by ONEOK.

Discounted Cash Flow Analysis

Evercore performed a discounted cash flow analysis of ONEOK by valuing the cash flows to be received by ONEOK based on the ONEOK Financial Projections from 2025 through 2028, which were derived from Wall Street Research. Evercore calculated the per share value range for ONEOK Common Stock by utilizing a range of discount rates based on ONEOK’s WACC, as estimated by Evercore based on CAPM and terminal values based on a range of estimated EBITDA multiples and perpetuity growth rates.

Evercore assumed a range of discount rates of 7.5% to 9.0% based on ONEOK’s WACC, a range of EBITDA multiples of 11.0x to 13.0x applied to ONEOK’s terminal period EBITDA and a range of perpetuity growth rates of 1.25% to 1.75% applied to ONEOK’s terminal period cash flows to derive a range of enterprise values. Evercore adjusted such enterprise values for projected debt, preferred equity, noncontrolling interest and cash as of December 31, 2024 and divided the resulting equity values by the number of projected ONEOK Common Stock outstanding as of December 31, 2024. The discounted cash flow analysis utilizing the EBITDA multiple terminal

value methodology resulted in an implied equity value per ONEOK Common Stock range of $110.25 to $144.56. The discounted cash flow analysis utilizing the perpetuity growth rate methodology to calculate terminal value resulted in an implied equity value per ONEOK Common Stock range of $95.51 to $146.63.

Public Companies and Partnerships Trading Analysis

Evercore performed a public companies and partnerships trading analysis of ONEOK by reviewing and comparing the market values and trading multiples of the following five publicly traded corporations and partnerships that Evercore deemed to have certain business characteristics that are similar to those of ONEOK and six publicly traded corporations that Evercore deemed to have certain business, legal and tax characteristics similar to those of ONEOK:

Large-Cap/Diversified Midstream Companies and Partnerships:

•        Energy Transfer LP

•        Enterprise Products Partners L.P.

•        Kinder Morgan, Inc.

•        MPLX LP

•        The Williams Companies, Inc.

Midstream C-Corporations:

•        Antero Midstream Corporation

•        DT Midstream, Inc.

•        Kinder Morgan, Inc.

•        Kinetik Holdings Inc.

•        Targa Resources Corp.

•        The Williams Companies, Inc.

Although the companies and partnerships were utilized to value ONEOK Common Stock for purposes of this analysis, no company or partnership used in the Public Companies and Partnerships Trading Analysis is identical or directly comparable to ONEOK. In order to calculate trading multiples, Evercore relied on publicly available filings with the SEC and equity research analyst estimates.

For the publicly traded corporations and partnerships, Evercore calculated the following trading multiples:

•        Enterprise Value/2025E EBITDA, which is defined as Enterprise Value divided by estimated EBITDA for the calendar year 2025.

•        Enterprise Value/2026E EBITDA, which is defined as Enterprise Value divided by estimated EBITDA for the calendar year 2026.

The mean and median Enterprise Value to EBITDA trading multiples of the corporations and partnerships are set forth below.

The table below includes relevant multiple ranges selected by Evercore based on the resulting ranges of Enterprise Value to EBITDA multiples and certain other considerations related to the specific characteristics of ONEOK noted by Evercore.

After adjusting for projected preferred equity, noncontrolling interests, debt and cash as of December 31, 2024, and dividing by the number of projected ONEOK Common Stock outstanding as of December 31, 2024, Evercore determined an implied equity value per ONEOK Common Stock range of $95.17 to $123.64 based on 2025 EBITDA from the OKE Financial Projections and an implied equity value per ONEOK Common Stock range of $102.43 to $133.64 based on 2026 EBITDA from the OKE Financial Projections.

Discounted Dividends Analysis

Evercore performed a discounted dividend analysis by valuing the projected cash dividends of ONEOK based on the OKE Financial Projections, which were derived from Wall Street Research. Evercore discounted projected dividends using cost of equity discount rates of 9.0% to 11.0% based on CAPM as well as a terminal yield range of 3.0% to 5.5% based on ONEOK’s trailing 52-week yield range. This analysis of the projected cash dividends resulted in an implied per ONEOK Common Stock value range of $70.42 to $125.39 based on the ONEOK Financial Projections.

Exchange Ratio Summary

Evercore analyzed the implied exchange ratios resulting from the various valuation methodologies utilized to value the EnLink Units based on the EnLink Financial Projections and ONEOK Common Stock based on the ONEOK Financial Projections. These valuation methodologies included the Discounted Cash Flow Analyses, a Public Companies and Partnerships Trading Analyses and a Discounted Distributions/Dividends Analyses. Evercore compared the low value per EnLink Unit to the high value per ONEOK Common Stock and the high value per EnLink Unit to the low value per ONEOK Common Stock for each respective analysis to derive ranges of implied exchange ratios. The resulting implied exchange ratio range using the Discounted Cash Flow Analyses (EBITDA exit) was 0.1066x to 0.2073x. The resulting implied exchange ratio range using the Discounted Cash Flow Analyses (perpetuity growth) was 0.0949x to 0.2102x. The resulting implied exchange ratio range using the Public Companies and Partnerships Trading Analyses was 0.1087x to 0.2212x based on 2025 EBITDA and 0.1020x to 0.2126x based on 2026 EBITDA. The resulting implied exchange ratio range using the Discounted Distributions/Dividends Analysis was 0.0733x to 0.1964x.

Evercore compared the results of the foregoing analyses to the Exchange Ratio of 0.1412 shares of ONEOK Common Stock for each EnLink Unit and noted that the Exchange Ratio was within the range of the implied exchange ratios for each of the valuation methodologies reviewed by Evercore.

General

The foregoing summary of certain material financial analyses does not purport to be a complete description of the analyses or data presented by Evercore. In connection with the review of the Mergers, Evercore performed a variety of financial and comparative analyses for purposes of rendering its opinion to the EnLink Conflicts Committee. The preparation of a fairness opinion is a complex process and is not necessarily susceptible to partial analysis or summary description. Selecting portions of the analyses or of the summary described above, without considering the analyses as a whole, could create an incomplete view of the processes underlying Evercore’s opinion. In arriving at its fairness determination, Evercore considered the results of all the analyses and did not draw, in isolation, conclusions from or with regard to any one analysis or factor considered by it for purposes of its opinion. Rather, Evercore made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all the analyses. In addition, Evercore may have given various analyses and factors more or less weight than other analyses and factors, and may have deemed various assumptions more or less probable than other assumptions. As a result, the ranges of valuations resulting from any particular analysis or combination of analyses described above should not be taken to be the view of Evercore with respect to the Exchange Ratio. No company or partnership used in the above analyses as a comparison is directly comparable to EnLink or ONEOK.

Furthermore, Evercore’s analyses involve complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the acquisition, public trading or other values of the corporations or partnerships used, including judgments and assumptions with regard to industry performance, general business, economic, market and financial conditions and other matters, many of which are beyond the control of EnLink, ONEOK and their respective advisors.

Evercore prepared these analyses solely for the information and benefit of the EnLink Conflicts Committee and for the purpose of providing an opinion to the EnLink Conflicts Committee as to whether, as of the date of the opinion, the Exchange Ratio is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders. These analyses do not purport to be appraisals or to necessarily reflect the prices at which the business or securities actually may be sold. Any estimates contained in these analyses are not necessarily indicative of actual future results, which may be significantly more or less favorable than those suggested by such estimates. Accordingly, estimates used in, and the results derived from, Evercore’s analyses are inherently subject to substantial uncertainty, and Evercore assumes no responsibility if future results are materially different from those forecasted in such estimates. The issuance of the opinion was approved by an opinion committee of Evercore.

Except as described above, the EnLink Conflicts Committee imposed no other instruction or limitation on Evercore with respect to the investigations made or the procedures followed by Evercore in rendering its opinion. The terms and conditions of the Mergers and the related terms and conditions of the transaction were determined through negotiations between the EnLink Conflicts Committee and ONEOK management. Evercore did not recommend any specific consideration to the EnLink Conflicts Committee or recommend that any specific consideration constituted the only appropriate consideration in the Mergers. Evercore’s opinion was only one of many factors considered by the EnLink Conflicts Committee in its evaluation of the Mergers and should not be viewed as determinative of the views of the EnLink Conflicts Committee with respect to the Mergers or the Exchange Ratio.

Under the terms of Evercore’s engagement letter with EnLink and the EnLink Conflicts Committee, EnLink has agreed to pay Evercore a fee of $2,000,000 upon rendering its opinion and a closing fee of $700,000 upon the closing of the Mergers. Evercore also received a fee of $300,000 upon execution of its engagement letter with EnLink and the EnLink Conflicts Committee. In addition, EnLink has agreed to reimburse Evercore for its reasonable expenses (including reasonable expenses relating to research, third party data fees and reasonable legal fees, expenses and disbursements) incurred in connection with its engagement and to indemnify Evercore and any of its members, partners, officers, directors, advisors, representatives, employees, agents, or controlling persons, if any, of Evercore or its affiliates against certain liabilities and expenses arising out of its engagement, or to contribute to payments which any of such persons might be required to make with respect to such liabilities.

During the two-year period prior to the date hereof, Evercore and its affiliates have not been engaged to provide financial advisory or other services to EnLink or ONEOK or their affiliates and Evercore has not received any compensation from EnLink or ONEOK or their affiliates during such period. Evercore and its affiliates may provide financial advisory or other services to EnLink and ONEOK or their affiliates in the future, and in connection with any such services Evercore may receive compensation.

Evercore and its affiliates engage in a wide range of activities for its and their own accounts and the accounts of customers, including corporate finance, mergers and acquisitions, equity sales, trading and research, private equity, placement agent, asset management and related activities. In connection with these businesses or otherwise, Evercore and its affiliates and/or its or their respective employees, as well as investment funds in which any of them may have a financial interest, may at any time, directly or indirectly, hold long or short positions and may trade or otherwise effect transactions for their own accounts or the accounts of customers, in debt or equity securities, senior loans and/or derivative products or other financial instruments of or relating to EnLink, ONEOK, and/or any of their respective affiliates or persons that are competitors, customers or suppliers of EnLink or ONEOK and/or any of their respective affiliates.

Interests of Certain EnLink Directors and Executive Officers in the Mergers

In considering the recommendations of the EnLink Conflicts Committee and the EnLink Board that EnLink unitholders vote to approve the Merger Agreement and the Mergers contemplated thereby, EnLink unitholders should be aware that certain of EnLink’s directors and executive officers may have interests in the Mergers that are different from, or in addition to, the interests of EnLink unitholders generally. Each of the EnLink Conflicts Committee and the EnLink Board was aware of these additional interests of its directors and executive officers and considered these potential interests, among other matters, in evaluating (and, in the case of the EnLink Conflicts Committee, negotiating) the Merger Agreement and the Mergers, in approving the Merger Agreement and in recommending the applicable merger-related proposals.

The following discussion sets forth certain of these interests in the Mergers of each executive officer or non-employee director of Manager.

EnLink Conflicts Committee Fees

Each member of the EnLink Conflicts Committee, consisting of directors who are not directly or indirectly affiliated with, and who are otherwise independent from, ONEOK and who are not members of EnLink’s management, will receive a single payment equal to $120,000, in connection with their services to EnLink with respect to the Mergers (which fee is not conditioned on the consummation of the Mergers); such amount to be paid in lieu of per-meeting fees or retainer fees otherwise payable to the EnLink Conflicts Committee members. The aggregate fees payable to members of the EnLink Conflicts Committee are expected to total $360,000.

Treatment of EnLink Equity Awards

The Merger Agreement provides for the treatment set forth below with respect to the EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time.

EnLink RIU Awards

At the First Merger Effective Time, each EnLink RIU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time.

EnLink PU Awards

At the First Merger Effective Time, each EnLink PU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each EnLink PU Tranche as identified in the applicable award agreement equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the GIP Interest Acquisition, taking into account any applicable proration provisions) multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture, except any performance-based vesting condition will not apply) as were applicable to such EnLink PU Award immediately prior to the First Merger Effective Time. For purposes of determining the number of EnLink Units subject to each EnLink PU Tranche, the following shall apply:

•        for each EnLink PU TSR Tranche and each EnLink PU DCF Tranche for which the performance period has closed prior to the closing date, the number of EnLink Units shall be determined based on the actual achievement of the performance criteria attained through the end of the performance

period, as previously certified by the EnLink Board or a committee thereof or, if not yet certified, as determined by the EnLink Board in good faith in the ordinary course of business consistent with past practice;

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has commenced but not closed as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance; and

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has not yet commenced as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance.

The Merger Agreement further provides that EnLink and ONEOK will take any and all actions reasonably necessary to effectuate the above. This includes ONEOK taking all actions necessary for the reservation, issuance and listing of shares of ONEOK Common Stock as are necessary to effectuate the transactions contemplated by the above. The following sets forth, for each EnLink executive officer who has served at any time since January 1, 2023, other than Alaina K. Brooks, who is omitted because she has separated from the Manager and is not entitled to any compensation or benefits in conjunction with the Mergers, the aggregate number of EnLink Units subject to outstanding EnLink RIU Awards and EnLink PU Awards held by such executive officer and the value of such EnLink RIU Awards and EnLink PU Awards assuming (i) as required under SEC rules, the closing price of an EnLink Unit is $15.79 (the “Estimated Closing Value”), which is equal to the average closing price of an EnLink Unit over the first five business days following the first public announcement of the entry into the Merger Agreement, (ii) a closing date of December 5, 2024 (which is the assumed date of the closing of the Mergers solely for purpose of the disclosure in this section, except we have assumed solely for purposes of the EnLink PU Award performance vesting treatment that the performance periods ending December 31, 2024, will be completed prior to the closing of the Mergers), (iii) the performance vesting treatment applicable to the EnLink PU Awards described below under “Treatment of the EnLink Equity Awards in the Mergers” (except for performance periods ending December 31, 2024, actual performance was calculated as of October 31, 2024, which is the latest practicable date that actual performance could be determined), and (iv) such executive officer remains continuously employed with the Manager or a subsidiary until the closing date of the Mergers.

____________

​(1)     The estimated value of the EnLink RIU Awards is equal to the sum of the product of (i) the Estimated Closing Value of $15.79 and (ii) the number of units underlying each EnLink RIU Award.

​(2)     EnLink PU Awards may vest up to 200% of the units covered by the award. EnLink PU Awards are shown in this table at the level of performance determined using the relevant assumptions described below under “Treatment of the EnLink Equity Awards in the Mergers.”

​(3)     The estimated value of the EnLink PU Awards is equal to the sum of (i) the product of (A) the Estimated Closing Value of $15.79 and (B) the number of units underlying each EnLink PU Award, determined using the relevant performance vesting treatment described below under “Treatment of the EnLink Equity Awards in the Mergers” (except for performance periods ending December 31, 2024, actual performance was calculated as of October 31, 2024, which is the latest practicable date that actual performance could be determined) and (ii) the associated distribution equivalents earned through the assumed closing date.

The following sets forth, for each EnLink non-management director who has served at any time since January 1, 2023, other than Kyle D. Vann, who retired from the EnLink Board and is not entitled to any compensation or benefits in conjunction with the Mergers, and William J. Brilliant, Benjamin M. Daniel, and Scott E. Telesz, who were affiliated with Global Infrastructure Management, LLC, and Pierce H. Norton II, Walter S. Hulse III, and Lyndon C. Taylor, who are affiliated with ONEOK, and each of whom did not or does not receive compensation in respect of their service as a director because they were or are affiliated with the owner of the Manager during their service, the aggregate number of EnLink Units subject to outstanding EnLink RIU Awards held by such director and the value of such EnLink RU Awards assuming (i) a closing price equal to the Estimated Closing Value, (ii) a closing date of December 5, 2024 and (iii) the director remains continuously in service with EnLink until such date. None of the EnLink directors hold EnLink PU Awards.

____________

​(1)      The estimated value of the EnLink RIU Awards is equal to the sum of the product of (i) the Estimated Closing Value of $15.79 and (ii) the number of units underlying each EnLink RIU Award.

(2)      Includes the EnLink Units underlying Ms. Cepak’s EnLink RIU Awards that she deferred under the Director Deferred Compensation Plan.

None of the EnLink RIU Awards or EnLink PU Awards held by EnLink’s executive officers or directors (as applicable) settle solely by reason of the occurrence of the closing. As the EnLink RIU Awards and EnLink PU Awards are being converted directly into awards based on ONEOK Common Stock using the Exchange Ratio, no monetary value is being received by EnLink’s executive officers and directors solely in connection with the conversion of their respective EnLink RIU Awards or EnLink PU Awards. However, pursuant to the underlying award agreements, the vesting of any unvested EnLink RIU Awards and EnLink PU Awards held by an executive officer or director would accelerate (including when converted into time-based restricted stock unit awards relating to shares of ONEOK Common Stock in connection with the Mergers) in the event an executive officer’s retirement or termination of employment by EnLink without “cause” or by the executive officer for “good reason” on or following the closing date or the director’s termination of service on or following the closing date, with the “double-trigger” full acceleration provisions applying because the GIP Interest Acquisition was a “change in control” for purposes of the EnLink RIU Awards and EnLink PU Awards. Additionally, one of EnLink’s directors, Ms. Cepak, has deferred EnLink RIU Awards under the EnLink Midstream, LLC Director Deferred Compensation Plan (the “Director Deferred Compensation Plan”), which such deferred EnLink RIU Awards will not be paid out solely as a result of the Mergers but would commence payout within 60 days of Ms. Cepak’s termination of service and be payable in accordance with her election or, if such termination occurs within one year of the GIP Interest Acquisition, which was a “change of control” under the Director Deferred Compensation Plan, payable in a lump sum.

Change in Control Agreements

All of our executive officers have entered into change in control agreements (the “Change in Control Agreements”) with EnLink Midstream Operating, LP (the “Operating Partnership”). Under the Change in Control Agreements, if, within a period that begins 120 days prior to and ends 24 months following a “change in control” (as defined in the Change in Control Agreement), which occurred upon the consummation of the GIP Interest Acquisition, an officer’s employment is terminated without “cause” (as defined in the Change in Control Agreement) or is terminated by the officer for “good reason” (as defined in the Change in Control Agreement) (each, a “Qualifying Termination”), such officer will be entitled to the following (in addition to any accrued but unpaid benefits):

•        a one-time lump sum payment equal to (i) the Severance Multiplier (as defined below) times the sum of (A) the officer’s base salary and (B) target bonus, plus (ii) an amount equal to the cost to the officer under COBRA to extend his or her medical insurance benefits for the COBRA Period (as defined below). For purposes of this benefit, the Severance Multiplier is 3 for Mr. Arenivas and 2.5 for all other executive officers. For purposes of this benefit, the COBRA Period is 36 for Mr. Arenivas and 30 for all other executive officers;

Potential 280G Mitigation Actions

The Mergers will not be a “change in ownership” or “change in effective control” of EnLink for purposes of Code Section 280G. However, the GIP Interest Acquisition was a “change in effective control” of EnLink for purposes of Code Section 280G. Accordingly, in connection with the GIP Interest Acquisition, given the timing of the GIP Interest Acquisition was not yet determined (and could have occurred in 2025), the EnLink Board approved the following potential 280G mitigation actions, which the Merger Agreement provides that EnLink will implement: (i) for all executive officers other than Benjamin Lamb, the acceleration of EnLink RIU Awards that would otherwise vest on January 1, 2025 to vest on December 27, 2024, and (ii) for all executive officers, the payment of annual bonuses at the target amount on December 13, 2024, in each case, subject to clawback on a voluntary termination of employment prior to the date the award would have otherwise vested. In addition, all executive officers other than Benjamin Lamb entered into 280G gross-up agreements with the selling entities in the GIP Interest Acquisition pursuant to which they will receive a gross-up payment to make them whole for any excise taxes incurred by them under Code Section 4999, subject to an aggregate cap of $5,000,000, in connection with the GIP Interest Acquisition but not in connection with any other transaction (the “280G Gross-Up Payments”).

Quantification of Potential Payments to EnLink’s Named Executive Officers in Connection with the Mergers

In accordance with Item 402(t) of Regulation S-K, the table below sets forth the estimated amounts of compensation that are based on or otherwise relate to the Mergers and that may be payable to those individuals (comprising EnLink’s existing executive officers) who were listed in the “Summary Compensation Table” that was set out in EnLink’s most recent securities filing for which disclosure was required under Item 402(c) of Regulation S-K (its 2023 annual report on Form 10-K), other than Alaina K. Brooks, who is omitted because she has separated from the Manager and is not entitled to any compensation or benefits in conjunction with the Mergers.

See the section above entitled “— Interests of Certain EnLink Directors and Executive Officers in the Mergers” for further information about the compensation disclosed in the table below. The amounts set out below assume (i) the Mergers occur on December 5, 2024, which is the assumed date of the closing of the Mergers solely for purposes of the disclosures in this section (except we have assumed solely for purposes of the EnLink PU Award performance vesting treatment that the performance periods ending December 31, 2024, will be completed prior to the closing of the Mergers), (ii) a price equal to the Estimated Closing Value of $15.79, (iii) the performance vesting treatment applicable to the EnLink PU Awards described below under “Treatment of the EnLink Equity Awards in the Mergers” (except for performance periods ending December 31, 2024, actual performance was calculated as of October 31, 2024, which is the latest practicable date that actual performance could be determined), (iv) the annual base salary, annual target bonus opportunity, and medical, dental, and vision plan coverage elections for each of the named executive officers remains unchanged from as of the date hereof, (v) none of EnLink’s named executive officers receives any additional equity-based awards following the date hereof and none of their equity awards that are outstanding as of the date hereof vest prior to the closing of the Mergers, (vi) each of EnLink’s named executive officer experiences a Qualifying Termination immediately following the Effective Time (or, solely with respect to the pro-rated target bonus portion of the severance payment, on December 31 of the year of closing, so that the full amount of the named executive officer’s target annual bonus is included), (vii) each named executive officer receives outplacement services up to the maximum amount of $50,000, (viii) the amount of the annual bonuses in respect of 2024 do not relate to the Mergers because such amount is based on the level of attainment of the performance measures under the applicable bonus plan and the amount of the annual bonus in respect of 2024 and 2025 is expected to be greater than the target amount paid early in December 2024 in connection with the potential Code Section 280G mitigation actions, (ix) each of EnLink’s named executive officers complies with the Severance Conditions and any other requirements in order to receive such payments and benefits, and (x) solely for purposes of these calculations, no named executive officer will receive “excess parachute payments” within the meaning of Code Section 280G, and accordingly, no 280G Gross-Up Payment will be made in connection with the Mergers. These amounts are

estimates that might become payable to the named executive officers, and the estimates are based on multiple assumptions that may or may not prove correct. Some of the assumptions are based on information not currently available and as a result the actual amounts received by a named executive officer may differ in material respects from the amounts set forth below.

Merger-Related Compensation

____________

(1)      Cash.    Represents the (i) lump sum cash severance payment, (ii) target bonus, and (iii) outplacement service payments payable under the Change in Control Agreements upon a Qualifying Termination (i.e., double-trigger) during the period that begins 120 days prior to and ends 24 months following a “change in control” as described above in the section entitled “— Change in Control Agreements.” The estimated amount of each component of the cash severance payment is shown in the following table:

____________

(2)      Equity.    Represents the potential value that each named executive officer could receive in connection with accelerated vesting and settlement (after being converted into time-based restricted stock unit awards relating to shares of ONEOK Common Stock) of EnLink RIU Awards and EnLink PU Awards (including the associated distribution equivalents earned on the EnLink Units underlying the EnLink PU Awards through the assumed closing date) upon a Qualifying Termination or Retirement (i.e., double-trigger) at any point during the period following a “change in control” as more fully described above in the section entitled “— Treatment of EnLink Equity Awards” (except for performance periods ending December 31, 2024, actual performance was calculated as of October 31, 2024, which is the latest practicable date that actual performance could be determined).

The estimated amount of each such payment is set forth in the table below:

Indemnification and Insurance

The Merger Agreement provides that the executive officers and directors of Manager and its subsidiaries will have the right to indemnification and continued coverage under directors’ and officers’ liability insurance policies for at least six years following the Effective Time. Please see the section entitled “The Merger Agreement — Directors’ and Officers’ Insurance and Indemnification.”

Treatment of the EnLink Equity Awards in the Mergers

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each EnLink RIU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each EnLink PU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each EnLink PU Tranche as identified in the applicable award agreement equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the GIP Interest Acquisition, taking into account any applicable proration provisions) multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture, except any performance-based vesting condition will not apply) as were applicable to such EnLink PU Award immediately prior to the First Merger Effective Time. For purposes of determining the number of EnLink Units subject to each EnLink PU Tranche, the following shall apply:

•        for each EnLink PU TSR Tranche and each EnLink PU DCF Tranche for which the performance period has closed prior to the closing date, the number of EnLink Units shall be determined based on the actual achievement of the performance criteria attained through the end of the performance period, as previously certified by the EnLink Board or a committee thereof or, if not yet certified, as determined by the EnLink Board in good faith in the ordinary course of business consistent with past practice;

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has commenced but not closed as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance; and

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has not yet commenced as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance.

The Merger Agreement further provides that EnLink and ONEOK will take any and all actions reasonably necessary to effectuate the above. This includes ONEOK taking all actions necessary for the reservation, issuance and listing of shares of ONEOK Common Stock as are necessary to effectuate the transactions contemplated by the above.

Accounting Treatment of the Mergers

In accordance with accounting principles generally accepted in the United States and in accordance with FASB’s ASC 810 — Consolidation, ONEOK will account for the Mergers as an equity transaction, as ONEOK controls EnLink both before and after the Mergers. Therefore, no gain or loss will be recognized in ONEOK’s consolidated income statement. In addition, the tax effects of the Mergers are reported as balance sheet adjustments consistent with ASC 740 — Income Taxes.

Regulatory Approvals

The completion of the Mergers is subject to antitrust review in the United States. In connection with the GIP Interest Acquisition, ONEOK filed under the HSR Act and any applicable waiting periods for the Mergers have been completed. The expiration or early termination of any HSR Act waiting period would not preclude the FTC and the DOJ from challenging the Mergers on antitrust grounds or from seeking to preliminarily or permanently enjoin the proposed Mergers.

Dividend Policy

Although ONEOK has paid cash dividends on ONEOK Common Stock in the past, the ONEOK Board may determine not to declare dividends in the future or may reduce the amount of dividends paid in the future. Following the closing of the Mergers, ONEOK expects to continue its dividend strategy. Under this strategy, ONEOK plans to continue to pay, on a quarterly basis, a fixed dividend amount to its shareholders. The declaration and payment of any future dividend will remain at the full discretion of the ONEOK Board and will depend on various factors, some of which are beyond ONEOK’s control, including its working capital needs, its ability to borrow, the restrictions contained in its indentures and credit facility, its debt-service requirements and the cost of acquisitions, if any. For additional information regarding risks associated with ONEOK’s dividends, please see the section entitled “Risk Factors — Declaration, payment and amounts of dividends, if any, distributed to ONEOK shareholders following the Mergers will be uncertain.”

Listing of ONEOK Common Stock; Delisting and Deregistration of EnLink Units

Prior to the completion of the Mergers, ONEOK will cause the shares of ONEOK Common Stock issued pursuant to and in accordance with the Merger Agreement to be approved for listing (subject, if applicable, to notice of issuance) for trading on the NYSE. If the Mergers are completed, the EnLink Units will cease to be listed on the NYSE and will be deregistered under the Exchange Act as promptly as practicable after the First Merger Effective Time, and EnLink will no longer be required to file periodic reports with the SEC pursuant to the Exchange Act.

No Appraisal Rights

Appraisal rights are statutory rights that, if applicable under law, enable shareholders of a corporation or unitholders of a limited liability company, as applicable, to dissent from a merger and to demand that such corporation or limited liability company pay the fair value for their shares or units as determined by a court in a judicial proceeding instead of receiving the consideration offered to such shareholders or unitholders in connection with the transaction. Under the DLLCA, the EnLink unitholders are not entitled to appraisal rights or dissenters’ rights in connection with the Mergers.

No dissenters’ or appraisal rights will be available with respect to the Mergers or the other transactions contemplated by the Merger Agreement.

THE MERGER AGREEMENT

The following description sets forth the principal terms of the Merger Agreement, which is attached as Annex A and incorporated by reference into this proxy statement/prospectus. The rights and obligations of the parties are governed by the express terms and conditions of the Merger Agreement and not by this description, which is summary by nature. This description does not purport to be complete and is qualified in its entirety by reference to the complete text of the Merger Agreement. You are encouraged to read the Merger Agreement carefully and in its entirety, as well as this proxy statement/prospectus, before making any decisions regarding any of the proposals described in this proxy statement/prospectus. This section is only intended to provide you with information regarding the terms of the Merger Agreement. Neither ONEOK nor EnLink intends that the Merger Agreement will be a source of business or operational information about ONEOK or EnLink. Accordingly, the representations, warranties, covenants and other agreements in the Merger Agreement should not be read alone, and you should read the information provided elsewhere in this proxy statement/prospectus and in the public filings ONEOK and EnLink make with the SEC, as described in the section entitled “Where You Can Find More Information.”

Explanatory Note Regarding the Merger Agreement

The Merger Agreement and this summary of terms are included to provide you with information regarding the terms of the Merger Agreement. Factual disclosures about ONEOK and EnLink contained in this proxy statement/prospectus or in the public reports of ONEOK and EnLink filed with the SEC may supplement, update or modify the factual disclosures about ONEOK and EnLink contained in the Merger Agreement. The representations, warranties and covenants contained in the Merger Agreement were made only for purposes of the Merger Agreement, as of a specific date. In addition, these representations, warranties and covenants were made solely for the benefit of the parties to the Merger Agreement and may be qualified and subject to important limitations agreed to by ONEOK and EnLink in connection with negotiating the terms of the Merger Agreement. In particular, in your review of the representations and warranties contained in the Merger Agreement and described in this summary, it is important to bear in mind that the representations and warranties were negotiated with a principal purpose of allocating risk between parties to the Merger Agreement rather than the purpose of establishing these matters as facts. The representations and warranties also may be subject to a contractual standard of materiality different from that generally applicable to shareholders and unitholders and reports and documents filed with the SEC and, in some cases, were qualified by the matters contained in the confidential disclosures that ONEOK and EnLink each delivered in connection with the Merger Agreement, which disclosures were not reflected in the Merger Agreement itself. Moreover, information concerning the subject matter of the representations and warranties, which do not purport to be accurate as of the date of this proxy statement/prospectus, may have changed since the date of the Merger Agreement and subsequent developments or new information qualifying a representation or warranty may have been included in this proxy statement/prospectus or in the respective public filings made by ONEOK and EnLink with the SEC.

Additional information about ONEOK and EnLink may be found elsewhere in this proxy statement/prospectus or incorporated by reference herein. Please see the section entitled “Where You Can Find More Information.”

Structure of the Mergers

Pursuant to the Merger Agreement, and in accordance with the DLLCA, (i) at the First Merger Effective Time, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK. Following the Mergers, EnLink Units will be delisted from the NYSE and will be deregistered under the Exchange Act as promptly as practicable after the First Merger Effective Time and will cease to be publicly traded.

Completion and Effectiveness of the Mergers

The closing of the Mergers will take place on the second business day after the conditions set forth in the Merger Agreement have been satisfied or waived (other than those conditions that by their nature are to be satisfied at the closing, but subject to the satisfaction or waiver of such conditions), or such other time as ONEOK and EnLink will mutually agree.

At the closing, (i) EnLink will cause a certificate of merger, executed in accordance with the relevant provisions of the EnLink Operating Agreement and the DLLCA (the “Certificate of First Merger”), to be duly filed with the Secretary of State of the State of Delaware prior to the Effective Time and (ii) following the First Merger Effective Time, Merger Sub II will cause a certificate of merger, executed in accordance with the relevant provisions of the limited liability company agreement of Merger Sub II and the DLLCA (the “Certificate of Second Merger”), to be duly filed with the Secretary of State of the State of Delaware. The First Merger will become effective at such time as the Certificate of First Merger has been duly filed with the Secretary of State of the State of Delaware, or at such later date or time as may be agreed by ONEOK and EnLink in writing and specified in the Certificate of First Merger. The Second Merger will become effective at such time as the Certificate of Second Merger has been duly filed with the Secretary of State of the State of Delaware, or at such later date or time as may be agreed by ONEOK and EnLink in writing and specified in the Certificate of Second Merger.

Merger Consideration

At the First Merger Effective Time, by virtue of the Mergers and without any further action on the part of ONEOK, Merger Sub I, EnLink or any holder of securities thereof:

•        all Excluded Units will automatically be canceled and cease to exist without any conversion thereof and no consideration will be delivered in exchange therefor; and

•        subject to certain terms of the Merger Agreement, each EnLink Unit issued and outstanding as of immediately prior to the First Merger Effective Time (other than Excluded Units) will automatically be converted into and will thereafter represent the right to receive from ONEOK 0.1412 duly authorized and validly issued shares of ONEOK Common Stock.

The number of shares of ONEOK Common Stock into which each EnLink Unit will be converted as specified in the second bullet above (as such number may be adjusted in accordance with the terms of the Merger Agreement) is referred to as the Merger Consideration, and such ratio is referred to as the Exchange Ratio.

Without limiting the parties’ respective obligations under certain parts of the Merger Agreement, if, during the period between the date of the Merger Agreement and the First Merger Effective Time, any change in the outstanding EnLink Units or shares of ONEOK Common Stock occurs as a result of any unit or share dividend, subdivision, reclassification, recapitalization, split, split-up, unit or share distribution, combination, exchange of units or shares or similar transaction, the Merger Consideration and any other similarly dependent item will be equitably adjusted to eliminate the effect of such event on the Merger Consideration or any such other amounts payable pursuant to the Merger Agreement and provide ONEOK, Merger Subs and the EnLink unitholders the same economic effect as contemplated by the Merger Agreement prior to such action.

No certificates or scrip of ONEOK Common Stock representing fractional shares of ONEOK Common Stock or book-entry credit of the same will be issued upon the surrender of EnLink Units, and such fractional interests will not entitle the owner thereof to vote or to have any rights as a holder of ONEOK Common Stock. The Exchange Ratio is fixed (subject to adjustments in accordance with the terms of the Merger Agreement), which means that it will not change between now and the First Merger Effective Time, regardless of changes in the market price of ONEOK Common Stock and EnLink Units. Any EnLink unitholder who would otherwise be entitled to receive a fraction of a share of ONEOK Common Stock pursuant to the Mergers (after taking into account all EnLink Units held immediately prior to the First Merger Effective Time by such holder) will, in lieu of such fraction of a share and upon surrender of such holder’s EnLink Unit Certificate formerly representing any EnLink Unit (other than an Excluded Unit) or each Book-Entry Common Unit, be paid in cash the dollar amount as specified in the Merger Agreement.

At the First Merger Effective Time, the units in Merger Sub I issued and outstanding immediately prior to the First Merger Effective Time will be converted into a number of EnLink Units, as the surviving entity in the First Merger, equal to the number of EnLink Units converted into the right to receive the Merger Consideration.

At the Effective Time, by virtue of the Second Merger, (i) each membership interest of EnLink, as the surviving entity in the First Merger, issued and outstanding immediately prior to the Effective Time (including the Manager’s interest) will be converted into one (1) duly authorized, validly issued, fully paid and non-assessable unit of Merger Sub II and (ii) each limited liability company interest of Merger Sub II that is outstanding immediately prior to the Effective Time will be unaffected by the Second Merger and will remain outstanding as a unit of Merger Sub II, as the Surviving Entity in the Second Merger.

Treatment of EnLink Equity Awards

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each EnLink RIU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each EnLink PU Award, whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each EnLink PU Tranche as identified in the applicable award agreement equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the GIP Interest Acquisition, taking into account any applicable proration provisions) multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture, except any performance-based vesting condition will not apply) as were applicable to such EnLink PU Award immediately prior to the First Merger Effective Time. For purposes of determining the number of EnLink Units subject to each EnLink PU Tranche, the following shall apply:

•        for each EnLink PU TSR Tranche and each EnLink PU DCF Tranche for which the performance period has closed prior to the closing date, the number of EnLink Units shall be determined based on the actual achievement of the performance criteria attained through the end of the performance period, as previously certified by the EnLink Board or a committee thereof or, if not yet certified, as determined by the EnLink Board in good faith in the ordinary course of business consistent with past practice;

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has commenced but not closed as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance; and

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has not yet commenced as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance.

The Merger Agreement further provides that EnLink and ONEOK will take any and all actions reasonably necessary to effectuate the above. This includes ONEOK taking all actions necessary for the reservation, issuance and listing of shares of ONEOK Common Stock as are necessary to effectuate the transactions contemplated by the above.

Exchange of Units

Exchange Agent

Prior to the closing date, ONEOK will select an exchange agent reasonably acceptable to EnLink for the purpose of exchanging EnLink Unit Certificates and Book-Entry Common Units for the Merger Consideration and paying any dividends or other distributions to which a holder of EnLink Units is entitled and any cash in lieu of any fractional shares to which such holder is entitled. On or prior to the closing date, ONEOK will deposit with the Exchange Agent, in trust for the benefit of the EnLink unitholders whose EnLink Units are converting into the right to receive the Merger Consideration at the First Merger Effective Time, ONEOK Common Stock (which will be uncertificated and registered in book-entry form), payable upon due surrender of the EnLink Unit Certificates (or affidavits of loss in lieu thereof with respect to such EnLink Unit Certificate) or Book-Entry Common Units. The shares of ONEOK Common Stock so deposited with the Exchange Agent, together with (i) any dividends or distributions received by the Exchange Agent with respect to such shares and (ii) cash to be paid in lieu of any fractional shares of ONEOK Common Stock, are referred to collectively as the “Exchange Fund.” The Exchange Agent will, pursuant to irrevocable instructions delivered by ONEOK at or prior to the First Merger Effective Time, deliver the Merger Consideration contemplated to be issued or paid pursuant to the terms of the Merger Agreement out of the Exchange Fund.

Exchange Procedures

Each holder of EnLink Units whose EnLink Units have been converted into the right to receive the Merger Consideration, upon delivery to the Exchange Agent of a properly completed letter of transmittal, duly executed and completed in accordance with the instructions thereto, and surrender of EnLink Unit Certificates (or affidavit of loss in lieu thereof with respect to certificated EnLink Units) or Book-Entry Common Units and such other documents as may reasonably be required by the Exchange Agent (including with respect to Book-Entry Common Units), will be entitled to receive in exchange therefor (i) the number of shares of ONEOK Common Stock representing, in the aggregate, the whole number of shares of ONEOK Common Stock that such holder has the right to receive, as provided in the Merger Agreement, and (ii) a check in the amount of (A) the cash in lieu of any fractional shares and (B) such dividends or other distributions as such holder has the right to receive pursuant to the Merger Agreement. Any and all shares of ONEOK Common Stock delivered will be uncertificated and will be registered in book-entry form. The Merger Consideration and such other amounts as reflected in the immediately preceding sentence will be paid as promptly as practicable after receipt by the Exchange Agent of the EnLink Unit Certificate (or affidavit of loss in lieu thereof with respect to certificated EnLink Units) or any applicable documentation with respect to the surrender of Book-Entry Common Units, and letter of transmittal in accordance with the foregoing. No interest will be paid or accrued on any Merger Consideration, cash in lieu of fractional shares or on any unpaid dividends and distributions payable to holders of EnLink Unit Certificates and Book-Entry Common Units. Until so surrendered, each such EnLink Unit Certificate and Book-Entry Common Unit will, after the First Merger Effective Time, represent for all purposes only the right to receive such Merger Consideration and such other amounts.

Lost, Stolen, or Destroyed Certificates

If any EnLink Unit Certificate is lost, stolen or destroyed, upon the making of an affidavit of that fact by the person claiming such EnLink Unit Certificate to be lost, stolen or destroyed and, if required by ONEOK, the posting by such person of a bond, in such reasonable amount as ONEOK may direct, as indemnity against any claim that may be made against it with respect to such EnLink Unit Certificate, the Exchange Agent will issue in exchange for such lost, stolen or destroyed EnLink Unit Certificate the Merger Consideration to be paid in respect of the EnLink Units represented by such EnLink Unit Certificate and pay cash in lieu of any fractional shares and any dividends and other distributions.

Fractional Shares

No certificates or scrip of ONEOK Common Stock representing fractional shares of ONEOK Common Stock or book-entry credit of the same will be issued upon the surrender of EnLink Units outstanding immediately prior to the First Merger Effective Time, and such fractional interests will not entitle the owner thereof to vote or to have any rights as a holder of shares of ONEOK Common Stock. Each holder of EnLink Units converted in the Mergers who would otherwise have been entitled to receive a fraction of a shares of ONEOK Common Stock (after taking into account all EnLink Units exchanged by such holder) will receive, in lieu thereof, cash (without interest and rounded up to the nearest whole cent) in an amount equal to the product of (i) the average of the closing sale price of a share of ONEOK Common Stock as reported on the NYSE for the ten (10) consecutive full trading days (in which shares of ONEOK Common Stock are traded on the NYSE) ending at the close of trading on the full trading day immediately preceding (and not including) the closing date and (ii) the fraction of a share of ONEOK Common Stock that such holder would otherwise be entitled to receive under the Merger Agreement. As promptly as practicable after the determination of the amount of cash, if any, to be paid to holders of fractional interests, ONEOK will cause the Exchange Agent to forward payments to such holders of fractional interests subject to and in accordance with the terms of the Merger Agreement. Payment of such cash consideration in lieu of issuing fractional shares of ONEOK Common Stock was not separately bargained-for consideration but merely represents a mechanical rounding off for purposes of avoiding the expense and inconvenience to ONEOK that would otherwise be caused by the issuance of fractional shares of ONEOK Common Stock.

Dividends and Distributions

No dividends or other distributions with respect to shares of ONEOK Common Stock issued in the First Merger will be paid to the holder of any unsurrendered EnLink Unit Certificate or Book-Entry Common Units until the holder thereof surrenders such EnLink Unit Certificate or Book-Entry Common Units in accordance with the Merger Agreement. Subject to the effect of escheat, tax or other applicable law, there shall be paid, without interest, to the record holder of the shares of ONEOK Common Stock, if any, issued in exchange therefor (i) at the time of such surrender, all dividends and other distributions payable in respect of any such shares of ONEOK Common Stock with a record date after the First Merger Effective Time and a payment date on or prior to the date of such surrender and not previously paid and (ii) following such surrender, at the appropriate payment date, the dividends or other distributions payable with respect to such shares of ONEOK Common Stock with a record date after the First Merger Effective Time but with a payment date subsequent to such surrender.

For purposes of dividends or other distributions in respect of shares of ONEOK Common Stock, all shares of ONEOK Common Stock to be issued pursuant to the First Merger shall be entitled to dividends pursuant to the immediately preceding sentence as if issued and outstanding as of the First Merger Effective Time. To the extent applicable, each EnLink Unit immediately prior to the First Merger Effective Time shall have continued rights to receive any distribution, without interest, with respect to such EnLink Units with a record date occurring prior to the First Merger Effective Time that may have been declared by the Manager or made by EnLink with respect to the Common Units in accordance with the terms of the EnLink Operating Agreement and the Merger Agreement, as applicable, and that remain unpaid as of the First Merger Effective Time.

Termination of the Exchange Fund

Any portion of the Exchange Fund that remains unclaimed by EnLink unitholders whose EnLink Units converted into the right to receive the Merger Consideration twelve months after the First Merger Effective Time will be returned to ONEOK, upon demand, and any such holder who has not exchanged his, her or its EnLink Units for the Merger Consideration in accordance with the Merger Agreement prior to that time will thereafter look only to ONEOK for delivery of the Merger Consideration, the payment of cash in lieu of any fractional shares payable pursuant to the Merger Agreement and the payment of any dividends and other distributions pursuant to the Merger Agreement in respect of such holder’s EnLink Units.

Withholding Rights

Each of ONEOK, Merger Sub I, EnLink, as the surviving entity in the First Merger, and the Exchange Agent (and, in each case, any applicable withholding agent acting on its behalf) are entitled to deduct and withhold from any amounts otherwise payable pursuant to the Merger Agreement such amounts, if any, as are required to be

deducted or withheld therefrom under the Code, or under any provision of applicable state, local or foreign tax law (and to the extent any deduction or withholding is required, such deduction or withholding may be taken in cash or ONEOK Common Stock, as determined by ONEOK). To the extent any amounts are so deducted or withheld and paid over to the appropriate governmental authority, such amounts will be treated for the purposes of the Merger Agreement as having been paid to the person in respect of which such deduction or withholding was made.

No Liability

None of ONEOK, either of the Merger Subs, EnLink and Manager is liable to any EnLink unitholder for any Merger Consideration or other amount duly delivered to a public official pursuant to applicable abandoned property laws.

No Interest

The Merger Agreement provides that no interest shall be paid or accrued on any Merger Consideration, cash in lieu of fractional shares or on any unpaid dividends and distributions payable to holders of EnLink Unit Certificates and Book-Entry Common Units.

Unit Certificates and Transfer Books

From and after the First Merger Effective Time:

•        there shall be no further registration on the books of EnLink of transfers of EnLink Units converted into the right to receive the Merger Consideration. If, after the First Merger Effective Time, EnLink Unit Certificates or Book-Entry Common Units are presented to the Exchange Agent or ONEOK, they will be canceled and exchanged for the consideration provided for, and in accordance with the procedures set forth, in the Merger Agreement; and

•        the holders of EnLink Unit Certificates or Book-Entry Common Units representing EnLink Units converted into the right to receive the Merger Consideration which were outstanding immediately prior to the First Merger Effective Time will cease to have any rights with respect to such EnLink Units, except as otherwise provided in the Merger Agreement or by applicable law.

Adjustments to Exchange Ratio

If between the date of the Merger Agreement and the First Merger Effective Time, any change in the outstanding EnLink Units or outstanding ONEOK Common Stock occurs as a result of any unit or share dividend, subdivision, reclassification, recapitalization, split, split-up, unit or share distribution, combination, exchange of units or shares or similar transaction, the Merger Consideration and any other similarly dependent item will be equitably adjusted to eliminate the effect of such event on the Merger Consideration or any such other amounts payable pursuant to the Merger Agreement and provide ONEOK, Merger Subs and the EnLink unitholders the same economic effect as contemplated by the Merger Agreement prior to such event.

Representations and Warranties

The Merger Agreement contains general representations and warranties made by each of ONEOK and, where applicable, Merger Subs, on the one hand, and EnLink and, where applicable, Manager, on the other, to the other party or parties, as applicable, regarding aspects of their respective businesses, financial condition and structure, as well as other facts pertinent to the Mergers. These representations and warranties are in many respects subject to materiality, knowledge and other similar qualifications contained in the Merger Agreement and expire at the Effective Time. The representations and warranties of each of ONEOK and, where applicable, Merger Subs, on the one hand, and EnLink and Manager on the other, were made solely for the benefit of the other party or parties, as applicable. In addition, those representations and warranties were intended not as statements of actual fact, but rather as a way of allocating risk between the parties, were modified by the confidential disclosure schedules attached to the Merger Agreement, were subject to the materiality standards described in the Merger Agreement (which may differ from what may be viewed as material by you) and were made only as of the date of the Merger Agreement and the closing date or another date as is specified in the Merger Agreement. Information concerning the subject matter of these representations or warranties may have changed since the date of the Merger Agreement. ONEOK and

EnLink will provide additional disclosure in their SEC reports to the extent that they are aware of the existence of any material facts that are required to be disclosed under federal securities laws and that might otherwise contradict the terms and information contained in the Merger Agreement and will update such disclosure as required by federal securities laws.

EnLink and Manager, as applicable, made a number of representations and warranties to ONEOK, including representations and warranties related to the following matters:

•        the organization, qualification to do business and good standing of EnLink and its subsidiaries;

•        the capital structure of EnLink and its subsidiaries;

•        the authority of EnLink, and the governmental and regulatory approvals necessary, to enter into the Merger Agreement and consummate the transactions contemplated thereby, and the absence of any loss, or creation of any lien, or violation of the organizational documents of EnLink and its subsidiaries or any applicable laws resulting from the consummation of the transactions contemplated by the Merger Agreement;

•        EnLink and its subsidiaries’ SEC filings and the financial statements contained therein;

•        EnLink’s internal controls over financial reporting and disclosure controls and procedures;

•        the absence of undisclosed liabilities for EnLink and its subsidiaries since September 30, 2024;

•        the conduct of EnLink and its subsidiaries’ business and the absence of certain adverse changes or events since December 31, 2023;

•        litigation, investigations, claims or judgments against EnLink or its subsidiaries;

•        EnLink and its subsidiaries’ compliance with laws and permits;

•        the accuracy of the information supplied by EnLink, Manager and EnLink’s subsidiaries for this document and the registration statement of which it is a part;

•        EnLink and its subsidiaries’ taxes, tax returns, tax status and other tax matters;

•        EnLink and its subsidiaries’ material contracts and the absence of a material breach of such contracts;

•        EnLink and its subsidiaries’ employee benefit plans and other employee benefits matters;

•        certain employment and labor matters related to EnLink and its subsidiaries;

•        EnLink and its subsidiaries’ environmental liabilities;

•        EnLink and its subsidiaries’ owned and leased real property and rights-of-way;

•        EnLink and its subsidiaries’ intellectual property;

•        the receipt by the EnLink Conflicts Committee of an opinion from Evercore as to the fairness, from a financial point of view, of the Exchange Ratio to the EnLink Unaffiliated Unitholders, as of the date of such opinion and based upon and subject to the assumptions, qualifications, limitations and other matters set forth therein;

•        investment banker, broker or finder fees in connection with the consummation of the Mergers;

•        EnLink and its subsidiaries’ insurance policies;

•        certain regulatory matters, including regulatory status, related to EnLink and its subsidiaries;

•        certain regulatory matters related to EnLink and its subsidiaries, including under the Investment Company Act of 1940, as amended; and

•        the absence of any additional ONEOK or Merger Subs representations or warranties beyond those in the Merger Agreement.

ONEOK also made a number of representations and warranties to EnLink, including representations and warranties related to the following matters:

•        the organization, qualification to do business and good standing of ONEOK and its subsidiaries;

•        the equity interests of ONEOK and capital structure of Merger Subs;

•        the authority of ONEOK and Merger Subs, and the governmental and regulatory approvals necessary, to enter into the Merger Agreement and consummate the transactions contemplated thereby, and the absence of any loss, or creation of any lien, or violation of the organizational documents of ONEOK and its subsidiaries, or any applicable laws resulting from the consummation of the transactions contemplated by the Merger Agreement;

•        the inapplicability of any state’s takeover laws;

•        ONEOK and its subsidiaries’ SEC filings and the financial statements contained therein;

•        ONEOK’s internal controls over financial reporting and disclosure controls and procedures;

•        the absence of undisclosed liabilities for ONEOK and its subsidiaries since December 31, 2023;

•        the conduct of ONEOK and its subsidiaries’ business and the absence of certain adverse changes or events since December 31, 2023;

•        litigation, investigations, claims or judgments against ONEOK or its subsidiaries;

•        ONEOK and its subsidiaries’ compliance with laws and permits;

•        the accuracy of the information supplied by ONEOK or its subsidiaries for this document and the registration statement of which it is a part;

•        ONEOK and its subsidiaries’ taxes, tax returns, tax status and other tax matters;

•        ONEOK and its subsidiaries’ material contracts and the absence of a material breach of such contracts;

•        ONEOK and its subsidiaries’ employee benefit plans and other employee benefits matters;

•        certain employment and labor matters related to ONEOK and its subsidiaries;

•        ONEOK and its subsidiaries’ environmental liabilities;

•        ONEOK and its subsidiaries’ owned and leased real property and rights-of-way;

•        ONEOK and its subsidiaries’ intellectual property;

•        investment banker, broker or finder fees in connection with the consummation of the Mergers;

•        ONEOK and its subsidiaries’ insurance policies;

•        certain regulatory matters related to ONEOK and its subsidiaries, including under the Investment Company Act of 1940, as amended;

•        certain regulatory matters, including regulatory status, related to ONEOK and its subsidiaries;

•        ONEOK’s ownership of EnLink Units; and

•        the absence of any additional EnLink representations or warranties beyond those in the Merger Agreement.

Definition of Material Adverse Effect

Many of the representations and warranties of ONEOK, Merger Subs, EnLink and Manager are qualified by a material adverse effect standard. For purposes of the Merger Agreement, “material adverse effect,” with respect to either ONEOK, Merger Subs, EnLink or Manager, is defined to mean any change, condition, effect, event or

occurrence that, individually or in the aggregate, has had or would reasonably be expected to have a material adverse effect on the business, financial condition or results of operations, of either (i) ONEOK and its subsidiaries, taken as a whole, or (ii) EnLink and its subsidiaries, taken as a whole, as the case may be, in either case; provided, however, that any adverse changes, conditions, effects, events or occurrences resulting from or due to any of the following shall be disregarded in determining whether there has been a material adverse effect:

(A)    changes, conditions, effects, events or occurrences generally affecting the United States or global economy, the financial, credit, debt, securities or other capital markets or political, legislative or regulatory conditions or changes in the industries in which ONEOK, Merger Subs, EnLink or Manager, as applicable, operates;

(B)    the announcement (in accordance with the terms of the Merger Agreement) or the existence of, compliance with the express terms of or the performance under, the Merger Agreement or the transactions contemplated thereby (including the impact thereof on the relationships, contractual or otherwise, of the applicable party and its subsidiaries with employees, labor unions, customers, suppliers or partners, and including any lawsuit, action or other proceeding with respect to the Mergers or any of the other transactions contemplated by the Merger Agreement);

(C)    any change in the market price or trading volume of the equity securities of the applicable party (it being understood and agreed that the foregoing shall not preclude any other party to the Merger Agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of material adverse effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a material adverse effect);

(D)    acts of war (whether or not declared), military actions, any act of sabotage, terrorism or other hostilities (or the escalation of the foregoing) or any hurricane, cyclone, tornado, earthquake, flood, tsunami, natural disaster, act of God or other force majeure events;

(E)    the outbreak and ongoing effects of contagious disease, epidemic or pandemic, or any worsening of such matters, or any declaration of martial law, quarantine or similar directive, policy or guidance or law or other action by any governmental authority in response thereto;

(F)    changes in any applicable laws or regulations applicable to ONEOK, Merger Subs, EnLink or Manager, or applicable accounting regulations or principles or the interpretation thereof;

(G)    changes, effects, events or occurrences generally affecting the prices of oil, natural gas, Refined Products, condensates or NGLs, or other commodities or for the applicable party’s raw material inputs and end products;

(H)    any failure by the applicable party to meet any internal or external projections, forecasts or estimates of revenues, earnings or other financial or operating metrics for any period (it being understood and agreed that the foregoing shall not preclude any other party to the Merger Agreement from asserting that any facts or occurrences giving rise to or contributing to such failure that are not otherwise excluded from the definition of material adverse effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a material adverse effect);

(I)     with respect to ONEOK only, any effect to the extent resulting from a change, condition, effect, event or occurrence that has a Material Adverse Effect on EnLink and its subsidiaries; and

(J)     (i) any change, condition, effect, event or occurrence which resulted from any ONEOK directive or (ii) any taking of any action at the request, approval or consent of ONEOK (in the case of EnLink), or EnLink (in the case of ONEOK);

provided, however, that changes, effects, events or occurrences referred to in subclauses (A), (D), (E), (F), and (G) above shall be considered for purposes of determining whether there has been or would reasonably be expected to be a material adverse effect if and to the extent such changes, effects, events or occurrences has had or would

reasonably be expected to have a disproportionate adverse effect on ONEOK or EnLink, as the case may be, and its subsidiaries, taken as a whole, as compared to other companies of similar size operating in the industries in which such party and its subsidiaries operate.

Covenants

The Merger Agreement contains additional agreements between the parties relating to the following matters, among other things:

•        making certain public announcements regarding the terms of the Merger Agreement or the transactions contemplated thereby;

•        taking steps as may be required to cause any dispositions of EnLink Units or acquisitions of ONEOK Common Stock resulting from the Merger Agreement transactions to be exempt under Rule 16b-3 under the Exchange Act;

•        the listing on the NYSE of the ONEOK Common Stock to be issued as consideration in connection with the Mergers; and

•        that EnLink will establish a record date for, duly call, give notice of, convene and hold a special meeting of its unitholders as promptly as reasonably practicable after the registration statement on Form S-4, of which this document forms a part, is declared effective under the Securities Act.

Conduct of Business Pending the Mergers

EnLink

EnLink has agreed that, during the period from the date of the Merger Agreement until the earlier of the First Merger Effective Time and the termination of the Merger Agreement, subject to specified exceptions, each of EnLink and the Manager shall, and shall cause each of their respective subsidiaries to, conduct its businesses:

•        in the ordinary course consistent with past practice; and

•        in compliance with the EnLink Midstream Interim Period Restricted Actions, dated as of October 15, 2024 (as may be amended or supplemented, or as any actions thereunder may be waived or approved by the applicable representative of ONEOK, from time to time). The EnLink Midstream Interim Period Restricted Actions restricts EnLink’s ability to take certain actions, including, among other things, (i) make capital expenditures, (ii) create or incur indebtedness, (iii) merge or consolidate with other businesses, and (iv) enter into or amend rights under material contracts.

EnLink has further agreed that during the period from the date of the Merger Agreement until the earlier of the First Merger Effective Time and the termination of the Merger Agreement, subject to specified exceptions, EnLink shall not, and shall not permit any of its subsidiaries to:

•        declare, authorize, set aside or pay any dividend or distribution payable in cash, stock or property in respect of any of EnLink’s or ENLK’s capital stock, other than (i) the declaration and payment of regular quarterly distributions to EnLink unitholders not in excess of $0.1325 per unit per quarter, (ii) the declaration and payment of distributions in cash or in kind to the holders of the ENLK Series B Units, in accordance with the ENLK Partnership Agreement, and as approved by the board of directors of the ENLK GP, and (iii) any distributions paid by EnLink or a subsidiary of EnLink to EnLink or another subsidiary of EnLink in the ordinary course of business;

•        adopt a plan or agreement of complete or partial liquidation, dissolution or restructuring or a plan or agreement of reorganization under any bankruptcy or similar law;

•        fail to maintain any material right-of-way and other material real property other than in the ordinary course of business consistent with past practice;

•        split, combine, divide, subdivide, reverse split, reclassify, recapitalize or effect any other similar transaction with respect to the capital stock or other equity interests of EnLink or any of its subsidiaries; or

•        agree, in writing or otherwise, to take any of the foregoing actions, or take any action or agree, in writing or otherwise, to take any action, including proposing or undertaking any merger, consolidation or acquisition, in each case, that would reasonably be expected to prohibit, prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers or the other transactions contemplated by the Merger Agreement.

ONEOK

ONEOK has agreed that, during the period from the date of the Merger Agreement until the First Merger Effective Time, subject to specified exceptions, ONEOK shall not, and shall not permit any of its subsidiaries to:

•        amend ONEOK’s or any of its subsidiaries’ organizational documents (whether by merger, consolidation, conversion or otherwise) in any manner that would reasonably be expected to (i) prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers or the other transactions contemplated by the Merger Agreement, or (ii) adversely affect (A) the value of the Merger Consideration to be obtained by the EnLink Unaffiliated Unitholders upon the consummation of the Mergers or (B) terms of the ONEOK Common Stock in any material respect;

•        declare, authorize, set aside or pay any dividend or distribution payable in cash, stock or property in respect of any of ONEOK’s capital stock, other than regular quarterly cash dividends on the ONEOK Common Stock in the ordinary course of business consistent with past practice and other than dividends or distributions with a record date after the First Merger Effective Time; provided, however, that nothing in the Merger Agreement prohibits ONEOK from increasing the quarterly cash dividend on ONEOK Common Stock;

•        split, combine, divide, subdivide, reverse split, reclassify, recapitalize or effect any other similar transaction with respect to any of ONEOK’s capital stock or other equity interests; provided, however, that nothing contained in the Merger Agreement prohibits ONEOK from making repurchases of ONEOK Common Stock pursuant to ONEOK’s publicly disclosed share repurchase program;

•        solely with respect to ONEOK or any of its material subsidiaries, adopt a plan of complete or partial liquidation, dissolution, consolidation, restructuring, recapitalization or other reorganization, or enter into a letter of intent or agreement in principle with respect thereto, other than consolidations, restructurings or reorganizations solely among ONEOK and its subsidiaries or among ONEOK’s subsidiaries;

•        directly or indirectly purchase, acquire or otherwise become beneficial owner of (or direct EnLink to repurchase, redeem or otherwise acquire) any additional EnLink Units; or

•        agree, in writing or otherwise, to take any of the foregoing actions, or take any action or agree, in writing or otherwise, to take any action, including proposing or undertaking any merger, consolidation or acquisition, in each case, that would reasonably be expected to prohibit, prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers or the other transactions contemplated by the Merger Agreement.

ONEOK has also agreed that, until the Effective Time or the earlier termination of the Merger Agreement, unless otherwise approved by the EnLink Board and the EnLink Conflicts Committee, ONEOK will not (i) amend, modify or revoke the Support Agreement, or (ii) directly or indirectly (A) other than to a ONEOK Entity (as defined in the Support Agreement) that agrees to be bound by the Support Agreement, sell, transfer, assign, tender in any tender or exchange offer, pledge, encumber, hypothecate or similarly dispose of (by merger, by distribution, by operation of law or otherwise), either voluntarily or involuntarily, or enter into any contract, option or other arrangement or understanding with respect to the sale, transfer, assignment, pledge, encumbrance, hypothecation or other disposition of (by merger, by distribution, by operation of law or otherwise), any EnLink Units owned by ONEOK as of the date of the Merger Agreement, (B) deposit any EnLink Units into a voting trust or enter into

a voting agreement or arrangement or grant any proxy, consent or power of attorney with respect thereto that is inconsistent with this paragraph, or (C) agree (regardless of whether in writing or orally) to take any of the actions referred to in the foregoing clauses (A) or (B).

No Change of Recommendation by EnLink

The EnLink Board or EnLink Conflicts Committee may at any time prior to obtaining the approval of the Merger Proposal by EnLink unitholders, withdraw, modify or qualify, or propose to publicly withdraw, modify or qualify its recommendation with respect to the Merger Proposal (an “EnLink adverse recommendation change”) if (and only if):

•        the EnLink Board or EnLink Conflicts Committee, after consultation with EnLink’s financial advisors and outside legal counsel, determines in good faith that a failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law;

•        the EnLink Board or the EnLink Conflicts Committee provides ONEOK at least three days’ prior written notice specifying in reasonable detail the reasons for its intention to take such action with respect to an EnLink adverse recommendation change; and

•        after providing such notice and prior to making such EnLink adverse recommendation change, the EnLink Board or the EnLink Conflicts Committee shall negotiate in good faith with ONEOK during the notice period (to the extent that ONEOK desires to negotiate) to make such revisions to the terms of the Merger Agreement, so that the failure to effect such EnLink adverse recommendation change would not be inconsistent with EnLink’s duties under the EnLink Operating Agreement and applicable law.

Efforts to Close the Mergers

ONEOK, on the one hand, and each of EnLink and Manager, on the other hand, will cooperate with the other and use and cause their respective subsidiaries to use its reasonable best efforts to:

•        take, or cause to be taken, all appropriate actions, and do, or cause to be done, all things, necessary, proper or advisable to cause the conditions to the closing to be satisfied as promptly as practicable (and in any event no later than the Outside Date) and to consummate and make effective, in the most expeditious manner practicable, the transactions contemplated by the Merger Agreement, including preparing and filing as promptly as practicable all documentation to effect all necessary filings, notifications, notices, petitions, statements, registrations, submissions of information, applications and other documents;

•        obtain promptly (and in any event no later than the Outside Date) all approvals, consents, clearances, expirations or terminations of waiting periods, registrations, permits, authorizations and other confirmations from any governmental authority or third party necessary, proper or advisable to consummate the transactions contemplated by the Merger Agreement; and

•        defend any proceedings challenging the Merger Agreement or the consummation of the transactions contemplated by the Merger Agreement or seek to have lifted or rescinded any injunction or restraining order or other order adversely affecting the ability of the parties to consummate the transactions contemplated by the Merger Agreement.

ONEOK and EnLink have also agreed to, and agreed to cause their respective subsidiaries to, use its reasonable best efforts to:

•        cooperate in all respects with each other party in connection with any filing or submission with a governmental authority in connection with the transactions contemplated by the Merger Agreement, including by providing the other party a reasonable opportunity to review and comment thereon, and in connection with any investigation or other inquiry by or before a governmental authority relating to the transactions contemplated by the Merger Agreement, including any proceeding initiated by a private person; and

•        promptly inform the other party of (and supply to the other party) any written communication received by such party from, or given by such party to any governmental authority and any material written communication received or given in connection with any proceeding by a private person, in each case regarding any of the transactions contemplated by the Merger Agreement. ONEOK and EnLink agree to take reasonable efforts to share information protected from disclosure under the attorney-client privilege, work product doctrine, joint defense privilege or any other privilege pursuant to the Merger Agreement in a manner so as to preserve the applicable privilege.

Proxy Statement/Registration Statement; Unitholders’ Meeting

ONEOK and EnLink agreed that as promptly as practicable following the date of the Merger Agreement, ONEOK and EnLink will jointly prepare and EnLink will file with the SEC a proxy statement and EnLink and ONEOK will jointly prepare and ONEOK will file with the SEC a registration statement on Form S-4, in which the proxy statement will be included as a prospectus.

ONEOK and EnLink will use their respective commercially reasonable efforts to have the registration statement declared effective under the Securities Act as promptly as practicable after its filing and keep the registration statement effective for so long as necessary to consummate the transactions contemplated by the Merger Agreement. EnLink will use its commercially reasonable efforts to cause the proxy statement/prospectus to be mailed to the EnLink unitholders as promptly as practicable after the registration statement is declared effective under the Securities Act.

No filing of, or amendment or supplement to, including by incorporation by reference, the registration statement or the proxy statement will be made by EnLink, ONEOK or any of their subsidiaries, without providing the other party a reasonable opportunity to review and comment thereon.

Each of ONEOK and EnLink will notify each other promptly of the receipt of any comments from the SEC or the staff of the SEC and of any request by the SEC or the staff of the SEC for amendments or supplements to the proxy statement, the registration statement or for additional information and shall supply each other with copies of (i) all correspondence between it or any of its representatives, on the one hand, and the SEC or the staff of the SEC, on the other hand, with respect to the proxy statement/prospectus, the registration statement or the transactions contemplated by the Merger Agreement and (ii) all orders of the SEC relating to the registration statement. If at any time prior to the First Merger Effective Time any information relating to EnLink or ONEOK, or any of their respective affiliates, officers or directors, is discovered by ONEOK or EnLink that should be set forth in an amendment or supplement to either the registration statement or this proxy statement/prospectus, so that any such document would not include any misstatement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, the party that discovers such information will promptly notify the other party to the Merger Agreement and an appropriate amendment or supplement describing such information will be promptly filed with the SEC and, to the extent required by applicable law, disseminated to the EnLink unitholders.

Directors’ and Officers’ Insurance and Indemnification

The parties have agreed that from and after the First Merger Effective Time, solely to the extent that EnLink or the Manager or any applicable subsidiary thereof would be permitted to indemnify an indemnified person immediately prior to the First Merger Effective Time, ONEOK and EnLink, as the surviving entity in the First Merger, jointly and severally agree to (i) indemnify and hold harmless against any reasonable costs or expenses, judgments, fines, losses, claims, damages or liabilities, penalties and amounts paid in settlement in connection with any actual or threatened proceeding, and, upon receipt by ONEOK of an undertaking by or on behalf of the indemnified person to repay such amount if it shall be determined in a final and non-appealable judgment entered by a court of competent jurisdiction that the indemnified person is not entitled to be indemnified nor be provided advancement of expenses with respect to each of the foregoing to, all indemnified persons to the fullest extent permitted under applicable law and (ii) honor the provisions regarding elimination of liability of officers and directors, indemnification of officers, directors and employees and advancement of expenses contained in the organizational documents of EnLink and the Manager immediately prior to the First Merger Effective Time, and ensure that the organizational documents of EnLink and the Manager or any of their respective successors or assigns (including Merger Sub II) shall, for a period of six years following the First Merger Effective Time, contain

provisions no less favorable with respect to indemnification, advancement of expenses and exculpation of present and former directors, officers and employees of EnLink and the Manager than are presently set forth in such organizational documents.

The parties have agreed that for six years from the First Merger Effective Time, ONEOK will maintain in effect ONEOK’s current directors’ and officers’ liability insurance policies covering acts or omissions occurring at or prior to the First Merger Effective Time with respect to indemnified persons (provided that ONEOK may substitute therefor policies with reputable carriers of at least the same coverage containing terms and conditions that are no less favorable to the indemnified persons); provided, however, that in no event shall ONEOK be required to expend more than an amount equal to 300% of current annual premiums paid by ONEOK for such insurance. If ONEOK in its sole discretion elects, then, in lieu of the obligations of ONEOK under the Merger Agreement, ONEOK may (but shall be under no obligation to), prior to the First Merger Effective Time, purchase a “tail policy” with respect to acts or omissions occurring or alleged to have occurred prior to the First Merger Effective Time that were committed or alleged to have been committed by such indemnified persons in their capacity as such. If a “tail policy” is purchased, Merger Sub II will, and ONEOK will cause Merger Sub II to, maintain such policies in full force and effect, and continue to honor the obligations thereunder.

ONEOK shall pay all reasonable expenses, including reasonable attorneys’ fees, that may be incurred by any indemnified person in enforcing the indemnity and other related obligations provided for in the Merger Agreement.

Public Disclosure

EnLink and ONEOK agreed that the initial press release with respect to the execution of the Merger Agreement would be a joint press release, reasonably agreed upon by ONEOK and EnLink. Except in connection with an EnLink adverse recommendation change, if any, no party will issue any other press release or make any other public announcement concerning the Merger Agreement or the transactions contemplated hereby (to the extent not previously issued or made in accordance with the Merger Agreement) (other than as may be required by applicable law or pursuant to the rules of the NYSE, in which event the party making the public announcement or press release shall, to the extent practicable, notify the other parties in advance of such public announcement or press release) without the prior approval of the other parties, which approval shall not be unreasonably withheld, delayed or conditioned.

Stock Exchange Listing

The ONEOK Common Stock deliverable to the EnLink Unitholders as contemplated by the Merger Agreement will have been approved for listing on the NYSE, subject to official notice of issuance.

Employee Matters

ONEOK has agreed that it will or will cause its affiliates, until the one-year anniversary of the closing date (or until employment terminates, if sooner) (the “Continuation Period”), to provide individuals who are employees of EnLink, Manager or their respective subsidiaries immediately prior to the closing and who remain employed with ONEOK or its affiliates immediately following the closing with (i) annual base salaries (or hourly wages, as applicable), annual cash bonus target opportunities, and annual long-term incentive award target opportunities (as more fully described at the end of this paragraph), in each case that are not less favorable than those provided to such employees immediately prior to the closing; (ii) employee benefits (excluding equity or equity-based benefits (other than with respect to the Continuation Period LTI Awards (as defined and described below)) and change in control, retention, nonqualified deferred compensation, defined benefit retirement and post-termination or retiree health or welfare benefits) that are, in the sole discretion of ONEOK, (A) substantially comparable in the aggregate to the employee benefits (subject to the same exclusions) that were available to such employees immediately prior to the closing under EnLink benefit plans, (B) substantially similar in the aggregate to the employee benefits (subject to the same exclusions) provided to ONEOK’s or its affiliates’ similarly situated employees as of the closing date, or (C) a combination of (A) and (B); and (iii) severance benefits for any such employee who is terminated by ONEOK or its affiliates without cause during the Continuation Period and signs and does not revoke a customary release of claims that include a pro-rated target annual bonus for the year of termination and otherwise are at least as favorable as the greater of the severance benefits provided under the severance policies of EnLink, Manager and their respective subsidiaries as in effect on the date of the Merger Agreement or the severance benefits provided under

the applicable severance policy of ONEOK or its affiliates as of the date of termination. The long-term incentive awards described in clause (i) of the first sentence of this paragraph (“Continuation Period LTI Awards”) will be granted to such employees (who remain employees as of the grant date) during a portion of the Continuation Period that falls during the first quarter of an applicable calendar year and will not be granted to the extent they duplicate long-term incentive awards, if any, granted prior to the closing date for the year in which the closing date occurs; provided, however, that, notwithstanding anything to the contrary, (A) ONEOK shall only be required to provide Continuation Period LTI Awards in respect of the year in which the closing date occurs and (B) the size of each such employee’s Continuation Period LTI Award made following the closing may be adjusted by ONEOK based on the such employee’s post-closing role with ONEOK and its subsidiaries so that it is consistent with similarly situated employees of ONEOK and its subsidiaries. Any Continuation Period LTI Awards granted by ONEOK following the closing will have terms and conditions that are the same as those of long-term incentive awards granted by ONEOK to similarly situated employees of ONEOK and its subsidiaries.

EnLink will take the following potential 280G mitigation actions: (i) for all executive officers other than Benjamin Lamb, the acceleration of EnLink RIU Awards that would otherwise vest on January 1, 2025 to vest on December 27, 2024, and (ii) for all executive officers, the payment of annual bonuses at the target amount on December 13, 2024, in each case, subject to clawback on a voluntary termination of employment prior to the date the award would have otherwise vested.

With respect to each such employee who begins to participate in a benefit plan of ONEOK or its affiliates, ONEOK will, or will cause its affiliate to, cause the applicable ONEOK benefit plan to credit each such employee for purposes of eligibility, vesting, and level of benefits under any paid-time off or severance policies or plans, with the service that is credited under the corresponding EnLink benefit plan in which such employee participates immediately prior to the closing date (including service with predecessor employers, to the extent such service is credited under such EnLink benefit plan), provided, however, that the ONEOK benefit plan may exclude any such prior service credit that would result in a duplication of benefits. With respect to each such employee who begins to participate in a ONEOK benefit plan, ONEOK will, or will cause its affiliates to, use commercially reasonable efforts to (i) cause each such employee to be eligible to participate in the applicable ONEOK benefits plans which provide medical, dental, prescription drug, or vision benefits without any waiting periods or any pre-existing condition exclusions and without regard to any evidence of insurability, actively-at-work or similar requirements and (ii) to give credit for all co-payments, deductibles, out-of-pocket costs and similar expenses paid by each such employee and such employee’s eligible dependents under a comparable benefit plan in which such employee participates immediately prior to the closing date and during the plan year of such ONEOK benefit plan in which the closing date occurs. ONEOK shall, or shall cause its affiliates to, recognize and credit each employee with the unused vacation time, sick leave, paid time off and other leave accrued by such employee as of immediately prior to the closing date.

Each such employee who participates in an EnLink benefit plan that is an annual bonus plan in respect of fiscal year 2024 shall be eligible to receive, subject to continued employment through the payment date, the following bonuses: (i) any unpaid annual bonus for fiscal year 2024, in an amount determined based on the level of attainment of the applicable performance measures under the EnLink annual bonus plan, as reasonably determined by the EnLink Board consistent with past practice, and paid in accordance with the terms of such EnLink annual bonus plan and (ii) an annual bonus for fiscal year 2025 in an amount determined based on the level of attainment of the performance measures under the annual bonus plan of ONEOK or one of its affiliates (which bonus will not be prorated).

Section 16 Matters

Prior to the First Merger Effective Time, ONEOK and EnLink have agreed to take all such steps as may be required to cause any dispositions of EnLink Units (including derivative securities thereof) or acquisitions of ONEOK Common Stock (including derivative securities thereof) resulting from the transactions contemplated by the Merger Agreement by each individual who is subject to the reporting requirements of Section 16(a) of the Exchange Act with respect to the EnLink, or will become subject to such reporting requirements with respect to ONEOK, to be exempt under Rule 16b-3 promulgated under the Exchange Act.

Treatment of Indebtedness

As of September 30, 2024, EnLink had no borrowings outstanding and $14.6 million in outstanding letters of credit under the EnLink Revolving Facility. As of September 30, 2024, EnLink had $260.0 million in outstanding borrowings under the EnLink AR Facility. Unless the EnLink Revolving Facility or the EnLink AR Facility are terminated or amended prior to or at the Effective Time, consummation of the Mergers would constitute a covenant breach and result in an event of default under the EnLink Revolving Facility and the EnLink AR Facility. The Merger Agreement requires Manager to cause EnLink and any of its applicable subsidiaries to deliver to ONEOK, at least one business day prior to the closing date, (i) the fully executed customary payoff letters in form reasonably acceptable to ONEOK and (ii) the final forms of all other payoff documentation in authorized form, to the extent applicable. In connection with the Mergers, ONEOK shall pay or cause to be paid the amounts set forth in such payoff letter.

As of September 30, 2024, EnLink had approximately $2.5 billion in senior notes outstanding and ENLK has approximately $2.1 billion in senior notes outstanding. In connection with the First Merger, EnLink, as the surviving company, will assume ENLK’s outstanding notes and, in connection with the Second Merger, ONEOK will assume EnLink’s outstanding notes, including ENLK’s outstanding notes assumed in the First Merger.

For a description of the EnLink Revolving Facility, EnLink AR Facility, EnLink’s senior notes and ENLK’s senior notes, see EnLink’s Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2024, filed with the SEC on November 8, 2024, which is incorporated by reference into this proxy statement/prospectus.

Treatment of ENLK Series B Units

The First Merger will constitute a Series B Change of Control (as such term is defined in the ENLK Partnership Agreement (as defined below)). Accordingly, immediately prior to the First Merger Effective Time, all outstanding ENLK Series B Units will be redeemed for cash or exchanged for EnLink Units in accordance with the terms of the Eleventh Amended and Restated Agreement of Limited Partnership of EnLink Midstream Partners, LP, dated as of September 8, 2023 (the “ENLK Partnership Agreement”). The Merger Agreement provides that EnLink and ONEOK shall reasonably cooperate with each other with respect to such Series B Change of Control and that EnLink shall cause ENLK’s election under the ENLK Partnership Agreement to either redeem for cash or exchange the Series B Preferred Units for EnLink Units to be made at ONEOK’s sole discretion.

Conditions to the Completion of the Mergers

Each party’s obligation to effect the Mergers is subject to the satisfaction (or waiver, if permissible under applicable law) on or prior to the closing date of the following conditions:

•        the approval of the Merger Proposal in accordance with applicable law and the organizational documents of EnLink by the EnLink unitholders;

•        no applicable law injunction, judgment or ruling enacted, promulgated, issued, entered, amended or enforced by any governmental authority shall be in effect enjoining, restraining, preventing or prohibiting consummation of the transactions contemplated by the Merger Agreement or making the consummation of the transactions contemplated by the Merger Agreement illegal;

•        the registration statement on Form S-4, of which this proxy statement/prospectus forms a part, has become effective under the Securities Act and no stop order suspending the effectiveness of the registration statement has been issued by the SEC, and no proceedings for that purpose have been initiated or threatened by the SEC;

•        the shares of ONEOK Common Stock deliverable to the EnLink unitholders as contemplated by the Merger Agreement have been approved for listing on the NYSE, subject to official notice of issuance; and

•        the receipt by EnLink on the closing date, but before the First Merger Effective Time, of an opinion, in form and substance reasonably satisfactory to EnLink and ONEOK, from nationally recognized tax counsel, dated as of the closing date, concluding that, on the basis of facts, representations and assumptions set forth or referred to in such opinion, for U.S. federal income tax purposes, the Mergers, taken together, should qualify as a “reorganization” within the meaning of Section 368(a) of the Code.

In addition, ONEOK’s, Merger Sub I’s and Merger Sub II’s obligation to effect the Mergers is subject to the satisfaction (or waiver, if permissible under applicable law) on or prior to the closing date of the following conditions:

•        the representations and warranties of EnLink and Manager as follows:

•        the representations and warranties of EnLink and Manager regarding capitalization and certain representations regarding authority and voting requirements (as set forth in Sections 4.2, 4.3(a) and 4.3(c) of the Merger Agreement) will be true and correct in all respects as of the date of the Merger Agreement and at and as of the closing date, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date), except for any de minimis breaches; and

•        all other representations and warranties of EnLink and Manager will be true and correct at and as of the closing date, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date), except for where the failure of such representations and warranties to be true and correct does not have, and would not reasonably be expected to have, individually or in the aggregate, a material adverse effect on EnLink.

•        EnLink and Manager’s performance in all material respects with all obligations required to be performed by them under the Merger Agreement at or prior to the closing date; and

•        ONEOK having received a certificate signed on behalf of EnLink and Manager by an executive officer of Manager certifying the matters of the immediately preceding bullets.

EnLink’s obligation to effect the Mergers is subject to the satisfaction (or waiver, if permissible under applicable law) on or prior to the closing date, of the following conditions:

•        the representations and warranties of ONEOK and Merger Subs as follows:

•        the representations and warranties of ONEOK regarding capitalization and certain representations regarding authority and ONEOK Board approval (as set forth in Sections 5.2, 5.3(a) and 5.3(c) of the Merger Agreement) will be true and correct in all respects as of the date of the Merger Agreement and at and as of the closing date, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date), except for any de minimis breaches; and

•        all other representations and warranties of ONEOK will be true and correct at and as of the closing date, as if made at and as of such time, except for where the failure of such representations and warranties to be true and correct does not have, and would not reasonably be expected to have, individually or in the aggregate, a material adverse effect on ONEOK.

•        ONEOK’s and Merger Subs’ performance in all material respects with all obligations required to be performed by them under the Merger Agreement at or prior to the closing date; and

•        EnLink having received a certificate signed on behalf of ONEOK by an executive officer of ONEOK certifying the matters of the immediately preceding bullets.

Termination of the Merger Agreement

The Merger Agreement can be terminated in the following circumstances:

•        Mutual Agreement.    Mutual agreement of ONEOK and EnLink, authorized by the EnLink Conflicts Committee and ONEOK Board.

•        Outside Date.    Termination by either party, if the Mergers have not closed by May 23, 2025.

•        Final Injunction or Other Law.    Termination by either party, if a permanent injunction has been issued or other law has been enacted prohibiting or making illegal the Mergers.

•        Unitholder Rejection.    Termination by either party, if EnLink unitholders fail to approve the Merger Proposal at the EnLink Special Meeting.

•        Change of Recommendation.    Termination by ONEOK, prior to EnLink unitholder approval of the Merger Proposal, if the EnLink Conflicts Committee changes its recommendation to the EnLink unitholders to vote for the Merger Proposal pursuant to an EnLink adverse recommendation change.

•        Breach of Representations or Covenants.    Termination by either party, if the other party has breached its representations or covenants in a way that causes a closing condition to fail.

Payment of Expenses

In the event of termination of the Merger Agreement by ONEOK due to an uncured breach by EnLink or Manager, EnLink has agreed to reimburse ONEOK for all of its reasonable documented out-of-pocket expenses in connection with the Merger Agreement and the transactions contemplated thereby, up to $10.0 million. In the event of termination of the Merger Agreement by EnLink due to an uncured breach by ONEOK or the Merger Subs, ONEOK has agreed to reimburse EnLink for all of its reasonable documented out-of-pocket expenses in connection with the Merger Agreement and the transactions contemplated thereby, up to $10.0 million.

Termination Fee

EnLink has agreed to pay ONEOK $143,978,000 if ONEOK validly terminates the Merger Agreement prior to the approval of the Merger Proposal by EnLink unitholders because the EnLink Conflicts Committee has made an EnLink adverse recommendation change.

Amendment; Supplement; Waiver

At any time prior to the First Merger Effective Time, the Merger Agreement may be amended or supplemented in any and all respects, whether before or after receipt of the approval of the Merger Proposal by EnLink unitholders, by written agreement of the parties hereto, by action taken or authorized by the ONEOK Board and the EnLink Board; provided, however, that the EnLink Board may not take or authorize any such action unless such action has been approved by the EnLink Conflicts Committee; provided, further, that following receipt of the approval of the Merger Proposal by EnLink unitholders, there shall be no amendment or change to the provisions of the Merger Agreement which by applicable law or stock exchange rule would require further approval by the EnLink unitholders without such approval. Notwithstanding the foregoing, no failure or delay by EnLink, the Manager, the EnLink Conflicts Committee, ONEOK or either of the Merger Subs in exercising any right under the Merger Agreement will operate as a waiver thereof nor will any single or partial exercise thereof preclude any other or further exercise of any other right under the Merger Agreement.

UNAUDITED PRO FORMA COMBINED INCOME STATEMENT OF ONEOK AND MAGELLAN

On September 25, 2023, ONEOK acquired all of Magellan Midstream Partners, L.P.’s (“Magellan”) outstanding common units in a cash-and-stock transaction, pursuant to the Agreement and Plan of Merger, dated May 14, 2023, by and among ONEOK, Otter Merger Sub, LLC and Magellan (the “Magellan Acquisition”). Each common unit of Magellan was exchanged for a fixed ratio of 0.667 shares of ONEOK Common Stock and $25.00 of cash, for a total consideration of $14.1 billion (collectively, the “Magellan Merger Consideration”). A total of approximately 135 million shares of ONEOK Common Stock were issued, with a fair value of approximately $9.0 billion as of the closing date of the Magellan Acquisition. ONEOK funded the cash portion of this acquisition with an underwritten public offering of $5.25 billion senior unsecured notes.

The following unaudited pro forma combined statement of income (the “Pro Forma Income Statement”) has been prepared to illustrate the estimated effects of Magellan Acquisition in accordance with Article 11 of Regulation S-X, as amended by the final rule, Release No. 33-10786 “Amendments to Financial Disclosures about Acquired and Disposed Businesses.” Based on this guidance, the Pro Forma Income Statement has been prepared from the respective historical consolidated financial statements of ONEOK and significant acquired and disposed businesses, which only includes the impact of the Magellan Acquisition. In addition, Release No 33-10786 replaced the existing pro forma adjustment criteria with simplified requirements to depict the accounting for the transaction (“Transaction Accounting Adjustments”) and present in the notes the reasonably estimable synergies and other transaction effects that have occurred or are reasonably expected to occur (“Management’s Adjustments”). Other transactions as a result of the Magellan Acquisition and considered material are included in the Pro Forma Income Statement as “Other Transaction Accounting Adjustments.” ONEOK has elected not to present Management’s Adjustments and only presents Transaction Accounting Adjustments and Other Transaction Accounting Adjustments in the Pro Forma Income Statement and notes thereto. The Pro Forma Income Statement for the year ended December 31, 2023, is presented as if the Magellan Acquisition had been completed on January 1, 2023.

The Pro Forma Income Statement has been developed from and should be read in conjunction with the audited consolidated financial statements of ONEOK included in its Annual Report on Form 10-K for the year ended December 31, 2023.

The Pro Forma Income Statement has been prepared to reflect adjustments to ONEOK’s historical consolidated financial information that are directly attributable to the Magellan Acquisition and factually supportable. Accordingly, the Pro Forma Income Statement reflects the following:

Transaction Accounting Adjustments

•        Adjustment of depreciation and amortization related to the step up of depreciable assets to estimated fair value;

•        Elimination of historical transactions between ONEOK and Magellan that would be treated as intercompany transactions after the Magellan Acquisition;

•        Application of ONEOK’s statutory tax rate to Magellan’s historical pre-tax income; and

•        Certain reclassifications to conform Magellan’s and ONEOK’s historical consolidated financial information.

Other Transaction Accounting Adjustments

•        ONEOK’s debt financing costs related to funding the cash portion of the Magellan Merger Consideration, including related fees.

The Pro Forma Income Statement has been updated to reflect the final fair values. The Pro Forma Income Statement is presented for illustrative purposes only and is not necessarily indicative of the operating results and financial position that would have occurred had the Magellan Acquisition occurred on the date indicated. Further, the Pro Forma Income Statement does not purport to project the future operating results or financial position of the combined company subsequent to the Magellan Acquisition. ONEOK’s actual results of operations subsequent to the Magellan Acquisition may differ materially from this Pro Forma Income Statement.

As ONEOK has elected not to present Management’s Adjustments, the notes to the Pro Forma Income Statement exclude projected synergies expected to be achieved as a result of the Magellan Acquisition, as well as any associated costs that may be required to achieve the identified synergies. Further, the Pro Forma Income Statement does not reflect the effect of any regulatory actions that may impact the results of the combined company following the Magellan Acquisition.

ONEOK, Inc. and Subsidiaries
Unaudited Pro Forma Statement of Income
Year ended December 31, 2023

The accompanying notes are an integral part of the Pro Forma Income Statement.

NOTES TO THE UNAUDITED PRO FORMA COMBINED INCOME STATEMENT

A.          BASIS OF PRESENTATION

The ONEOK historical financial information has been derived from ONEOK’s Annual Report on Form 10-K for the year ended December 31, 2023. The Magellan historical financial information has been derived from Magellan’s financial reporting records for the period ended September 25, 2023. Certain historical consolidated financial information has been reclassified to conform Magellan’s and ONEOK’s financial statement presentation. The Pro Forma Income Statement should be read in conjunction with the historical consolidated financial statements and related notes thereto of ONEOK and Magellan.

The Magellan Acquisition and related adjustments are described in the accompanying notes. All material adjustments have been made that are necessary to present fairly the Pro Forma Income Statement, in accordance with Article 11 of Regulation S-X of the SEC. The Pro Forma Income Statement does not purport to represent what the combined company’s results of operations would have been if the transactions had actually occurred on the date indicated, nor are they indicative of ONEOK’s future results of operations. Actual results may differ materially from the assumptions and estimates reflected in the Pro Forma Income Statement.

ONEOK has determined that no significant adjustments are necessary to conform Magellan’s historical consolidated financial information to the accounting policies used by ONEOK. As a result, the Pro Forma Income Statement presented assumes there are no differences in accounting policies. However, as discussed in Note B, certain reclassifications have been made to conform Magellan’s and ONEOK’s historical presentation.

ONEOK’s historical consolidated financial information included in the Pro Forma Income Statement for the year ended December 31, 2023, includes a non-recurring operational gain of $779 million ($600 million, net of taxes) related to the receipt of insurance proceeds following a fire that occurred in 2022 at ONEOK’s 210 MBbl/d Medford, Oklahoma, natural gas liquids fractionation facility. The gain is recorded within other operating (income) expense, net and is further discussed in ONEOK’s Annual Report on Form 10-K for the year ended December 31, 2023.

B.          PRO FORMA ADJUSTMENTS

The Pro Forma Income Statement has been adjusted to reflect reclassifications to conform ONEOK’s and Magellan’s financial statement presentations. Adjustments included in the “Transaction Accounting Adjustments” column reflect the impact of the Magellan Acquisition. Adjustments included in the “Other Transaction Accounting Adjustments” column reflect financing associated with the Magellan Acquisition. Both of these columns include an estimated tax impact of the pro forma adjustments.

(a)     The following reclassifications have been made to conform Magellan’s and ONEOK’s financial statement presentations:

Pro Forma Income Statement for the year ended December 31, 2023:

•        To reclassify $986 million of product sales revenue to commodity sales;

•        To reclassify $1,441 million of transportation and terminals revenues and $17 million of affiliate management fee revenue to services;

•        To reclassify $817 million of cost of product sales and $62 million of operating costs, primarily representing fuel and utilities costs, to cost of sales and fuel;

•        To reclassify $301 million of operating costs and $234 million of general and administrative costs to operations and maintenance;

•        To reclassify $69 million of operating costs and $2 million of general and administrative costs to general taxes;

•        To reclassify $44 million of operating costs to transaction costs;

•        To reclassify $61 million of earnings of non-controlled entities included in operating income to equity in net earnings from investments, below operating income;

•        To reclassify $1 million of gain on disposition of assets and $4 million of interest income to other income (expense), net; and

•        To reclassify $2 million of interest capitalized to interest expense, net of capitalized interest.

(b)    Reflects the elimination of historical transactions between ONEOK and Magellan that are treated as intercompany transactions after the Magellan Acquisition.

(c)     Reflects the increase to depreciation expense of $39 million resulting from the increase in the basis of Magellan’s property, plant and equipment. ONEOK utilized an estimated useful life of 42 years and the straight line method to amortize the increase in basis. The estimated useful life is based on ONEOK’s expectation of the assets’ useful lives.

(d)    Reflects the increase in amortization expense of $37 million, resulting from the recognized intangible assets acquired. ONEOK utilized the straight line method of amortization for purposes of the Pro Forma Income Statement and an average useful life of 23 years.

(e)     Reflects adjustment related to the amortization of equity method basis differences for Magellan’s investments in unconsolidated affiliates. ONEOK has assessed that basis differences are attributable to property, plant and equipment and contract-based customer relationship intangible assets and utilized a useful life of 42 years to amortize the basis differences.

(f)     Reflects the adjustment for reduction in compensation expense resulting from the conversion of Magellan’s equity awards to ONEOK equity awards at the closing date of the Magellan Acquisition, as this does not include the severance cost of awards that immediately vested upon closing of the Magellan Acquisition. These awards will vest in shares of ONEOK Common Stock. The Pro Forma Income Statement for the year ended December 31, 2023, includes a reduction of $12 million in expenses. The adjustment is attributable to the difference between Magellan’s historical share-based compensation expense included in Magellan’s historical results and the share-based compensation expense related to the fair value of the replacement awards issued as part of the Magellan Acquisition. The excess in fair value of the replacement share-based awards is recognized ratably over post-combination service periods presented, utilizing the term of Magellan’s vesting period.

(g)    Reflects the adjustment to increase cost of sales and fuel by $60 million ($46 million net of tax), to adjust Magellan’s inventory to fair value, as the inventory is expected to be sold within one year of the acquisition date.

(h)    Reflects the removal of Magellan’s non-recurring transaction costs of $44 million ($34 million, net of tax) related to the Magellan Acquisition, including fees paid for financial advisory, legal and other professional services.

(i)     Reflects a net increase to interest expense of $27 million, related to the amortization of the discount resulting from the fair value remeasurement of Magellan’s debt.

(j)     Reflects the tax effect of Magellan’s historical pre-tax income at ONEOK’s blended federal and state statutory rate of 23%.

(k)    Reflects an increase to interest expense, including amortization of debt issuance costs, of $243 million, associated with the issuance of new senior fixed-rate notes used to fund the cash portion of the consideration. The increased interest expense relates to the issuance of new senior unsecured notes and assumes issuance occurred on January 1, 2023.

(l)     Reflects the tax effect of the Transaction Accounting Adjustments and Other Transaction Accounting Adjustments at the blended federal and state statutory rate of 23%.

MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES

The following is a discussion of U.S. federal income tax consequences to U.S. holders (as defined below) of the Mergers and of owning and disposing of shares of ONEOK Common Stock received in the Mergers. This discussion is limited to U.S. holders that hold their EnLink Units, and will hold their shares of ONEOK Common Stock received in the Mergers, as capital assets within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion is based upon the Code, Treasury Regulations promulgated thereunder, administrative rulings and judicial decisions in effect as of the date of this proxy statement/prospectus, all of which are subject to change at any time, possibly with retroactive effect. Any such change could affect the accuracy of the statements and conclusions set forth in this discussion. No ruling has been, or is expected to be, sought from the IRS with respect to any of the tax consequences discussed below. As a result, there can be no assurances that the IRS will not assert, or that a court would not sustain, a position contrary to any of the conclusions set forth below.

This discussion does not address tax consequences that may be relevant to particular U.S. holders in light of their individual circumstances, including, without limitation:

•        banks, financial institutions or insurance companies;

•        real estate investment trusts;

•        regulated investment companies or mutual funds;

•        “controlled foreign corporations” or “passive foreign investment companies”;

•        dealers and brokers in stocks and securities or currencies;

•        traders in securities that use a mark-to-market method of tax accounting;

•        tax-exempt entities;

•        certain former citizens or long-term residents of the United States;

•        persons that received EnLink Units as compensation for the performance of services;

•        holders of options, restricted units or bonus units granted under any EnLink benefit plan;

•        persons that hold EnLink Units or ONEOK Common Stock as part of a hedge, straddle, appreciated financial position, conversion or other “synthetic security” or integrated investment or risk reduction transaction for U.S. federal income tax purposes;

•        S-corporations or other pass-through entities (or investors in S-corporations or other pass-through entities);

•        persons whose “functional currency” is not the U.S. dollar;

•        “qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds; or

•        persons subject to special tax accounting rules as a result of any item of gross income with respect to the EnLink Units or ONEOK Common Stock being taken into account in an applicable financial statement.

If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds EnLink Units, the tax treatment of a partner in such partnership will generally depend on the status of the partner and the activities of the partner and the partnership. Any entity treated as a partnership for U.S. federal income tax purposes that holds EnLink Units, and any partners in such partnership, are strongly urged to consult their tax advisors regarding the tax consequences of the Mergers and of owning and disposing of shares of ONEOK Common Stock received in the Mergers.

Units generally will recognize gain or loss equal to the difference, if any, between the amount of cash received and the tax basis allocated to such fractional share of ONEOK Common Stock, unless the receipt of cash has the effect of a distribution of a dividend under the tests set forth in Section 302 of the Code, in which case, such cash received would be treated as a dividend to the extent of such U.S. holder’s ratable share of earnings and profits as determined for U.S. federal income tax purposes. Gain or loss recognized with respect to cash received in lieu of a fractional share of ONEOK Common Stock generally will be capital gain or loss, and will be long-term capital gain or loss if, as of the effective date of the Mergers, such U.S. holder’s holding period for the fractional share of ONEOK Common Stock received pursuant to the First Merger is greater than one year. For U.S. holders that are non-corporate holders, long-term capital gains generally will be taxed at a U.S. federal income tax rate that is lower than the rate for ordinary income or for short-term capital gains. The deductibility of capital losses is subject to limitations.

Tax Consequences to U.S. Holders of Owning and Disposing of Shares of ONEOK Common Stock Received in the Mergers

Distributions on Shares of ONEOK Common Stock

For U.S. federal income tax purposes, distributions of cash by ONEOK to a U.S. holder with respect to shares of ONEOK Common Stock received in the Mergers will generally be included in such U.S. holder’s income as dividend income to the extent of ONEOK’s current or accumulated “earnings and profits” as determined under U.S. federal income tax principles. A portion of the cash distributed to ONEOK shareholders by ONEOK after the Mergers may exceed ONEOK’s current and accumulated earnings and profits. Distributions of cash in excess of ONEOK’s current and accumulated earnings and profits will be treated as a non-taxable return of capital reducing a U.S. holder’s adjusted tax basis in such U.S. holder’s shares of ONEOK Common Stock and, to the extent the distribution exceeds such U.S. holder’s adjusted tax basis, as capital gain from the sale or exchange of such shares of ONEOK Common Stock. Dividends received by a corporate U.S. holder may be eligible for a dividends received deduction, subject to applicable limitations. Dividends received by an individual U.S. holder may be taxed at the lower applicable long-term capital gains rate if such dividends are treated as “qualified dividend income” for U.S. federal income tax purposes.

Sale, Exchange, Certain Redemptions or Other Taxable Dispositions of Shares of ONEOK Common Stock

Upon the sale, exchange, certain redemptions or other taxable dispositions of shares of ONEOK Common Stock received in the Mergers, a U.S. holder will generally recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of any other property received upon such taxable disposition of shares of ONEOK Common Stock and (ii) the U.S. holder’s adjusted tax basis in such shares of ONEOK Common Stock. Such capital gain or loss will be long-term capital gain or loss if the U.S. holder’s holding period in the shares of ONEOK Common Stock disposed of is more than twelve months at the time of such taxable disposition. Long-term capital gains of non-corporate taxpayers are generally taxed at reduced rates. Capital losses recognized by a U.S. holder may offset capital gains and, in the case of individuals, no more than $3,000 of ordinary income. Capital losses recognized by U.S. holders that are corporations may only be used to offset capital gains.

Information Reporting and Backup Withholding

Information returns may be required to be filed with the IRS in connection with the Mergers and in connection with distributions made with respect to, or dispositions of, shares of ONEOK Common Stock received in the Mergers. A U.S. holder may be subject to U.S. backup withholding on payments made pursuant to the Mergers or on distributions made with respect to, or on payments made pursuant to dispositions of, shares of ONEOK Common Stock received in the Mergers unless such holder provides proof of an applicable exemption or a correct taxpayer identification number and otherwise complies with the applicable requirements of the backup withholding rules. Any amount withheld under the U.S. backup withholding rules is not an additional tax and will generally be allowed as a refund or credit against the U.S. holder’s U.S. federal income tax liability provided that the U.S. holder timely furnishes the required information to the IRS.

THE U.S. FEDERAL INCOME TAX DISCUSSION SET FORTH ABOVE IS INTENDED ONLY AS A SUMMARY OF THE MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES OF THE MERGERS. IT IS NOT A COMPLETE ANALYSIS OR DISCUSSION OF ALL POTENTIAL TAX EFFECTS THAT MAY BE IMPORTANT TO A PARTICULAR U.S. HOLDER. ALL U.S. HOLDERS ARE STRONGLY ENCOURAGED TO CONSULT THEIR TAX ADVISORS AS TO THE SPECIFIC TAX CONSEQUENCES TO THEM OF THE MERGERS AND OF THE OWNERSHIP AND DISPOSITION OF ONEOK COMMON STOCK RECEIVED IN THE MERGERS, INCLUDING ANY TAX REPORTING REQUIREMENTS AND THE APPLICABILITY AND EFFECT OF ANY U.S. FEDERAL, U.S. STATE OR LOCAL, NON-U.S. OR OTHER TAX LAWS AND OF POTENTIAL CHANGES IN SUCH LAWS.

COMPARISON OF RIGHTS OF ENLINK UNITHOLDERS AND ONEOK SHAREHOLDERS

If the Mergers are completed, EnLink unitholders will receive shares of ONEOK Common Stock.

EnLink is a Delaware limited liability company subject to the DLLCA, while ONEOK is an Oklahoma corporation subject to the OGCA. If the Mergers are completed, the rights of EnLink unitholders who become ONEOK shareholders through the exchange of units and the rights of ONEOK shareholders will be governed by the OGCA, the ONEOK Charter and the Amended and Restated By-Laws of ONEOK, dated as of February 22, 2023 (the “ONEOK Bylaws”).

The following description summarizes certain material differences between the rights of EnLink unitholders and the rights of ONEOK shareholders. This does not purport to be a complete statement of all those differences, or a complete description of the specific provisions referred to in this summary. The identification of specific differences is not intended to indicate that other equally significant or more significant differences do not exist. EnLink unitholders should read carefully the relevant provisions of the OGCA, the ONEOK Charter, the ONEOK Bylaws, as well as the EnLink Operating Agreement and the Manager LLCA. Copies of the documents referred to in this summary may be obtained as described under “Where You Can Find More Information.”