The deal will include £367m of funding from the European Investment Bank, guaranteed by the Swedish government. It is not known at this stage how much the deal is worth.
Meanwhile, GM Europe is also set to sell its Vauxhall and Opel operations to a group led by Magna International, the Canadian auto parts company.
In the US, GM has filed for Chapter 11 bankruptcy and is rationalising its range of brands as it moves to restructure its loss making business.
In a statement, GM says the sale to Koenigsegg is “expected to close by the end of the third quarter of this year”. Saab went into creditor protection on February 20.
Koenigsegg is a small player in the car industry and produces only 18 cars a year, while employing 45 people. In contrast, Saab last year sold 93,000 cars.