Unable to find a buyer for Saab after a year-long search, General Motors said Friday that it would begin shutting down operations at the Swedish carmaker, according to The New York Times.

G.M. had been in final sales negotiations with a Dutch maker of high-end sports cars, Spyker Cars, but issues arose during the due diligence process that made the sale impossible before G.M.'s Jan. 1 deadline, the company said in a statement.

"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," the president of G.M. Europe, Nick Reilly, said.

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

Saab will continue to honor warranties, while providing service and spare parts to current Saab owners around the world, G.M. said. Mr. Reilly said that the move was not a bankruptcy or forced liquidation, so he expected Saab to pay its debts, including those of suppliers.

But with a narrow, though loyal, customer base focused on Sweden, Britain and the American Northeast, Saab has proved too small to lure the world's big automakers, many of which are seeking tie-ups to increase economies of scale.

Earlier this month, the Beijing Automotive Industry Holding Company struck a deal for the right to produce versions of the older 9-5 and 9-3 models in China.

In late November, the Swedish sports carmaker, Koenigsegg, backed out of the deal to buy the unit. It was the third time in less than two months that a sale of a G.M. brand has been called off, reflecting the difficulty of selling underperforming divisions in the midst of a global sales slump.