DETROIT — General Motors Co. announced yesterday it will begin winding down its Saab operations after concluding "certain issues" arose that prevented the brand from being sold off to a potential buyer.

GM had hoped to sell Saab to Koenigsegg Group AB, but that deal fell through last month. Then GM entered into discussions with Spyker Cars.

"During the due diligence, certain issues arose that both parties believe could not be resolved. As a result, GM will start an orderly wind-down of Saab operations," GM said in a statement.

The Detroit automaker said Saab will continue to honor warranties and provide service and spare parts to current Saab owners.

"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. In order to maintain operations, Saab needed a quick resolution," GM Europe President Nick Reilly said in a statement.

"We regret that we were not able to complete this transaction with Spyker Cars. We will work closely with the Saab organization to wind down the business in an orderly and responsible manner."

The failure to sell Saab comes after a deal to sell GM's Saturn division fell apart at the last minute and GM's board of directors undid a deal to sell the Opel operations.