Porsche’s failed attempt to takeover Volkswagen has seen the firm record a loss of 4.4 billion euro (£3.9bn).
Porsche had launched a takeover bid for VW and had built a 51 per cent stake in the company by the summer.
But the firm had to abandon the takeover after its debts spiralled out of control and it is now set to complete a merger with VW by the end of 2011.
The firm’s loss for the year to the end of July came a year after it returned an 8.6bn (£7.67bn) euro profit.
Despite its huge losses, Porsche said in a statement that if its failed takeover was taken out of the figures, it would be the "most profitable automobile manufacturer in the world".