"Despite the best efforts of all involved, it has become very clear that the due diligence required to complete this complex transaction could not be executed in a reasonable time," GM Europe President Nick Reilly said in a statement. "In order to maintain operations, Saab needed a quick resolution."
GM was scheduled to provide more details during a conference call with reporters Friday morning. The Detroit automaker said it will continue to honor Saab customer warranties.
GM first sought a buyer for Saab in January as part of its restructuring, which included plans to downsize its brands to four from eight. It was previously in talks to sell Saab to a consortium led by the Swedish sports car maker Koenigsegg Group AB, but it turned to Spyker after Koenigsegg withdrew from the talks in November.
Speculation has since been rampant on the future of Saab. Earlier this week, GM Chairman and CEO Ed Whitacre told reporters he had "a sense it's possible" that the sale to Spyker would go through, but conceded the brand would close by the end of the year if the talks fell apart.
On Monday, China's Beijing Automotive Industry Holdings -- originally part of the Koenigsegg consortium -- announced it had agreed to buy some powertrain technology from Saab. It gave no details of costs or timing of that purchase.