General Motors said it would restate its financial results for 2001 by up to $400m because of accounting errors while losses for the second quarter of 2005 quadrupled after a revision of its holding in Fuji Heavy Industries.

The world largest carmaker, which is already suffering from four consecutive quarters of losses and the collapse of its main parts supplier Delphi, said in a filing with the Securities and Exchange Commission that its 2001 earnings were overstated by $300m to $400m, but the final amount has not been determined.