General Motors Corp. (GM) on Wednesday said it will restate its financial statements for 2001 because they were overstated by about $300 million to $400 million.

Accounting errors led to the wrong figures for net income from continuing operations, which were overstated by about 25 to 35 percent, the world's largest auto maker said in a filing with the Securities and Exchange Commission.

GM has been conducting an internal review of credits received from suppliers and its accounting treatment of them from 2000 to 2005. "This issue is one of the matters that is also being investigated by the SEC," GM said.

GM said the review shows that the auto maker erroneously recognized some supplier credits as income in the year in which they were received rather than in the future periods to which they were attributable.

The car maker said it expects its restatement of financial statements for 2001 to have a material impact to the results previously reported for that year.

GM, which has lost about $3 billion this year, is grappling with high health care costs, foreign competitors cutting into its market share and stalled sales of its profitable sport utility vehicles amid rising gasoline prices.

GM's main parts supplier — Delphi Corp. (DPHIQ) — filed for bankruptcy in October, and GM could face up to $12 billion in liabilities at Delphi.

GM shares earlier in the day fell to their lowest point in 13 years amid increasing concerns the auto maker has underfunded its pension plans and that workers at Delphi could go on strike.

GM in its filing also said it will restate financial statements for periods after 2001 that may be affected by the erroneous accounting.

"However, the effect of any such restatement in subsequent periods is expected to be immaterial to those financial statements," the company said.

The auto giant said it expects to complete the review before it files its annual report for 2005.

GM said in its filing on Wednesday that it restated its second-quarter 2005 results to reflect the appropriate value of its investment in Fuji Heavy Industries Ltd. GM had said in October that it would make the restatement.

Concerns raised by the Securities and Exchange Commission also prompted the auto maker to reclassify cash flows for the year ended December 31, 2004.

The amounts for the six months ended June 30, 2004 have been reclassified to be consistent with the six months ended June 30, 2005, GM said.

The Audit Committee of the Board of Directors has warned investors they should no longer rely on GM's previously filed financial statements for 2001, or the related auditors' reports after that year, due to the likelihood of a material restatement of the results.

GM shares closed at $24.63, down $1.24 or 4.79 percent, in Wednesday trade on the New York Stock Exchange.