Stockholm - Swedish luxury carmaker Koenigsegg and Norwegian investors have struck a preliminary deal to buy General Motors' Swedish unit Saab, a source familiar with the matter said on Thursday.The source told Reuters a letter of intent had been signed between the parties and said the financing of the deal had been agreed, leaving only minor issues to be resolved."The deal is there now and a few minor details remain," said the source, who declined to be identified.Saab spokesman Eric Geers declined to comment on the report, saying the carmarker was "in the final stages of negotiations" and was still targeting a sale by early July.Swedish television channel SVT, citing unnamed sources, reported the deal had been struck after intensive negotiations in Zurich, Switzerland. "Final negotiations about details on the deal will go on in the next months," SVT said on its website.Saab Automobile, which was put up for sale by its now bankrupt US parent earlier this year, had been in talks with two or three bidders in the past weeks with Deutsche Bank advising in the sales process.The brand, whose sales comprised just over 1% of GM's total sales volume last year, has been hit hard by the economic downturn that has savaged sales on both sides of the Atlantic.Saab, one of Sweden's best-known brands, has said it needs $1 billion of financing to help it overhaul production and launch new models while absorbing expected losses of about 3 billion crowns ($370 million) this year.Luxury carsKoenigsegg, founded by Christian von Koenigsegg in 2004, makes luxury sportscars. The company's headquarters is located in Angelholm, in southern Sweden, which currently houses 45 full-time employees, according to its website.The tiny vehicle maker, part-owned by Norwegian entrepreneur Bard Eker through his holding company Eker Group AS, had sales of 106 million crowns last year.The Swedish government said on Thursday it had authorised the debt office to begin talks with Saab on state loan guarantees. "The decision means that the Debt Office can initiate negotiations with Saab, the EIB and the coming owner, once one is revealed, about terms for state guarantees," the government said in a statement.The guarantees are needed for Saab to receive loans from the European Investment Bank to finance environmentally friendly vehicles.Sweden has until now said it was not prepared to consider loan guarantees for Saab unless the carmaker finds a private investor to underwrite its business plan.