MLM Martin Marietta Materials Inc

 CUSIP Number 573284106

Date of Event Which Requires Filing of this Statement: December 31, 2011

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

 [ ] Rule 13d-1(b)
 [ x ] Rule 13d-1(c)
 [ ] Rule 13d-1(d)

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 1) Name of reporting person:
 Harbour Advisors
 (the "Investment Manager")
 A Business Unit of CI Investments Inc.
 2 Queen Street East, Twentieth Floor
 Toronto, Ontario, M5C 3G7

 2) Check the appropriate box if a member of a group:
 a) x
 b) n/a

 3) SEC use only

 4) Place of organization:
 Toronto, Ontario, Canada

Number of shares beneficially owned by each reporting person with:
 5) Sole voting power: 2,450,000
 6) Shared voting power: - 0 -
 7) Sole dispositive power: 2,450,000
 8) Shared dispositive power: - 0 -

 9) Aggregate amount beneficially owned by each reporting person:
 2,450,000

 10) Check if the aggregate amount in row (9) excludes certain shares:
 n/a

 11) Percent of class represented by amount in row (9):
 5.36%

 12) Type of reporting person:
 IA, CO

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 Item 1a) Name of issuer:
 Martin Marietta Materials, Inc.

 Item 1b) Address of issuer's principal executive offices:
 2710 Wycliff Road
 Raleigh, NC 27607
 United States


 Item 2a) Name of person filing:
 Harbour Advisors
 (the "Investment Manager")
 A Business Unit of CI Investments Inc.

 Item 2b) Address of principal business office:
 CI Investments
 2 Queen Street East
 Twentieth Floor
 Toronto, On
 M5C 3G7
 Canada

 Item 2c) Citizenship:
 Ontario, Canada corporation


 Item 2d) Title of class of securities:
 Common Stock

 Item 2e) CUSIP No. 573284106

 Item 3) If this statement is filed pursuant to Rule 13d-1(b), or
13d-2(b), check whether the person filing is a :
 (a)[ ] Broker or dealer under Section 15 of the Act.
 (b)[ ] Bank as defined in Section 3(a)(6) of the Act.
 (c)[ ] Insurance Company as defined in Section 3(a)(6) of the Act.
 (d)[ ] Investment Company registered under Section 8 of the
 Investment Company Act.
 (e)[ ] Investment Adviser registered under Section 203 of the
 Investment Advisers Act of 1940.
 (f)[ ] Employee Benefit Plan, Pension Fund which is subject to
 ERISA of 1974 or Endowment Funds; see 240.13d-1(b)(ii)(F).
 (g)[ ] Parent holding company, in accordance with 240.13d-1(b)(ii)(G)
 (h) [ ] Group, in accordance with 240.13d-1(b)(1)(ii)(J).

 Item 4) Ownership:

 (a) Amount beneficially owned: 2,450,000

 (b) Percent of Class: 5.36%

 (c) Number of shares as to which such person has:
 (i) sole power to vote or to direct the vote:
 2,450,000
 (ii) shared power to vote or to direct the vote:
 - 0 -
 (iii) sole power to dispose or to direct the disposition of:
 2,450,000
 (iv) shared power to dispose or to direct the disposition of:
 - 0 -

 Item 5) Ownership of Five Percent or less of a class:
 n/a

 Item 6) Ownership of more than Five Percent on behalf of another
 person:

 n/a

 Item 7) Identification and classification of the subsidiary which
 acquired the security being reported on by the parent holding company:
 n/a

 Item 8) Identification and classification of members of the group:
 Harbour Advisors
 (the "Investment Manager")
 A Business Unit of CI Investments Inc.

 Item 9) Notice of dissolution of group:
 n/a

 Item 10) Certification:

 By signing below I certify that, to the best of my knowledge
 and belief, the securities referred to above were acquired and
 are held in the ordinary course of business and were not
 acquired and are not held for the purpose of or with the
 effect of changing or influencing the control of the issuer of
 the securities and were not acquired and are not held in
 connection with or as a participant in any transaction having
 that purpose or effect.


 Signature
 -----------

 After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

 --------------------------------
 Date January 17, 2012

 CI Investments Inc.
 On behalf of the Investment Manager


 By___________________________________________
 Janet Gillies
 Chief Compliance Officer