A deal by General Motors Co to sell its Saab brand collapsed on Tuesday when the buyer pulled out in a move that threatens the Swedish luxury brand with closure.

GM had been aiming to close a deal by the end of next month to sell Saab to a partnership led by the Swedish luxury car builder Koenigsegg and backed by China's Beijing Automotive Industrial Holding Ltd.

Koenigsegg said in a statement on Tuesday that it had withdrawn from the sale process, about five months after the two sides had reached a preliminary deal for Saab.

The time factor has always been critical for our strategy to breathe new life into the company, Koenigsegg said.

The development represents a setback for GM, which has been working to shed brands as part of a more narrowly focused sales strategy after emerging from a bankruptcy in July backed by over $50 billion in U.S. government financing.

A tentative deal by GM to sell its Saturn brand to Penske Automotive Group also collapsed at the end of September, just before it was expected to close.

GM Chief Executive Fritz Henderson said the automaker would take the next few days to consider the options for Saab.

We're obviously very disappointed with the decision to pull out of the Saab purchase, Henderson said in a statement. Many have worked tirelessly over the past several months to create a sustainable plan for the future of Saab by selling the brand and its manufacturing interests to Koenigsegg Group AB. 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.

GM's 13-member board is scheduled to meet next Tuesday in Detroit for a regular monthly meeting and the question of what to do with Saab will now lead the agenda, said one person with direct knowledge of the situation.

There are no other bidders for the brand, meaning that GM's only options would be to restart the sale process or opt for closure, the person said.

Because of the pressure GM faces to focus on its remaining four core brands -- Chevrolet, Cadillac, Buick and GMC -- a wind-down of Saab operations is likely, the person said.

(Additional reporting by Bernie Woodall and Soyoung Kim)

(Reporting by Kevin Krolicki and David Bailey, editing by Dave Zimmerman)