A Swedish automaker has backed out of a deal to buy Saab from General Motors, casting serious doubt on the future of the troubled brand, according to The Associated Press.

Koenigsegg Group AB said Tuesday it has decided to scrap the deal, which was announced in June. Financial details of the acquisition were not disclosed by GM.

The collapse of the Saab sale is the third GM deal to fall through this year for a variety of reasons.

GM Chief Executive Fritz Henderson says the company is disappointed in the decision and will take the next several days to figure out what to do.

A person briefed on the deal said Tuesday that Saab's future is now unclear. GM's board will have to decide the company's next move, said the person, who asked not to be identified because the decision has not been made.

Before Koenigsegg emerged as a buyer, GM had contingency plans to shut down Saab's operations, the person said. Saab went into a court-protected restructuring Feb. 20 after the Swedish government said it wouldn't buy Saab from GM.