WFR Sunedison, Inc.

SunEdison Inc. on Wednesday said it is again delaying the filing of its annual report, citing in part the discovery of "material weaknesses in its internal controls over financial reporting."

Shares in the solar-energy company, which have lost 67% over the past three months and 91% over the past year, slid another 16% to $1.73 in premarket trading. The delay comes a week after Vivint Solar Inc. terminated its merger agreement with SunEdison.

The company, whose deadline to file its 10-K was previously extended to March 15, didn't give a new target date.

SunEdison said the material weaknesses primarily result from "deficient information technology controls in connection with newly implemented systems." The company said additional procedures are necessary to complete the annual financial statements.

SunEdison had said in a regulatory filing earlier this month it would delay its 2015 earnings report while its board investigates claims from a former and a current employee challenging the accuracy of the company's financial disclosures.

On Wednesday, SunEdison said its audit committee investigation of the accuracy of the company's anticipated financial position previously disclosed to the board isn't finished.

The company said to date, the additional procedures performed as a result of the material weaknesses identified and the investigation by the audit committee "have not resulted in the identification of any material misstatements or restatements of the company's audited or unaudited consolidated financial statements or disclosures for any period previously reported by the company."

Vivint had terminated its merger agreement with SunEdison, saying the solar-energy company's mounting financial woes had kept it from meeting the deal's obligations.

Vivint said SunEdison's failure to consummate the merger when required constitutes a willful breach of the agreement, and the rooftop-solar company plans to "seek all legal remedies available to it."

Barclays PLC, Citigroup Inc., Goldman Sachs Group Inc. and UBS Group AG had balked at providing loans they had committed to fund the takeover, according to people familiar with the matter. The banks had told SunEdison its failure to provide them with up-to-date financial statements meant it hadn't fulfilled a condition of the loan agreement, the people said.

Investors have soured on SunEdison's "yieldco" business model, which relies heavily on selling finished power projects to two publicly traded subsidiaries. Stock-price tumbles at those entities, TerraForm Power Inc. and TerraForm Global Inc., made it harder for them to raise funds to buy projects, setting off a series of investor worries.

TerraForm on Wednesday also said it would delay the filing of its annual report as its financial reporting and control processes rely significantly on SunEdison systems and personnel. TerraForm said it hasn't identified any material misstatements or restatements in its previously reported financials.

The company said, however, it has discovered material weaknesses in internal controls over financial reporting primarily because of ineffective controls in relation to its Enterprise Resource Planning systems and processes for validating revenue recognition.

"We are working to remediate these issues as promptly as practicable," it said in a statement.

TerraForm said that because it delayed filing its 10-K beyond the 15-day extension period, it received a notification letter from Nasdaq saying it is no longer in compliance with market rules. The company has until May 16 to submit a plan to Nasdaq as to how it plans to regain compliance with listing requirements. TerraForm said if it is unable to file its 10-K by then, it intends to submit a compliance plan.

Shares of TerraForm, which have fallen 20% over the past three months and 70% over the past year, skidded 19% lower to $8.56 premarket.

Write to Anne Steele at Anne.Steele@wsj.com

(END) Dow Jones Newswires

March 16, 2016 08:45 ET (12:45 GMT)

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