General Motors' hopes of closing the sale of its Swedish luxury brand Saab by the end of December have collapsed with the withdrawal of Koenigsegg Group AB, a Swedish supercar maker that had been backed by Bejing Automotive Industrial Holding Ltd. of China.

In a terse statement announcing the decision, General Motors CEO Fritz Henderson said, "We're obviously very disappointed with the decision [by Koenigsegg] to pull out of the Saab purchase. Given the sudden change in direction, we will take the next several days to assess the situation and will advise on the next steps next week."

General Motors, which came out of bankruptcy in July with federal backing of more than $50 billion, has faced a rocky road in divesting itself of its various brands as part of its overall restructuring strategy.

At the end of September, the company's agreement with Penske Automotive for the sale of Saturn fell through, as did the shift of a majority stake in Opel to Magna International. GM subsequently opted to keep Opel.

Plans for Hummer to go to Sichuan Tengzhong Heavy Industrial Machinery Co. of China are still in the works, but Pontiac will be phased out. GM wants to be left with only four U.S. brands: Chevrolet, Cadillac, GMC, and Buick.