GM is trying to turn around its fortunes

The company now says its losses totalled $10.6bn last year, with the additional $2bn caused by errors at a mortgage subsidiary.

GM said as a result it was now going to delay filing its 2005 annual report.

The company is also going to restate its results for the years 2000 to 2004 due to the same error.

Is this another blow to GM management? I would say yes Analyst Kevin Tynan

It added that it had further incorrectly accounted for some supplier payments.

Unhappy investors

Analysts said the revelation of accounting errors would be yet another blow to the credibility of a firm that is struggling to turn around its fortunes.

"Is this another blow to management? I would say yes," said Kevin Tynan, an analyst with Argus Research.

"But you can't say management was on very steady ground in the eyes of investors [in the first place]."

JPMorgan analyst Himanshu Patel said the multitude of accounting errors raised concerns about the company's internal accounting controls.

Detroit-based GM has been cutting both costs and output to cope with falling sales.

Earlier this month GM announced plans to raise $2bn through the sale of 17.4% of its stake in Japanese carmaker Suzuki.