(August 18, 2009) General Motors Corp. said Tuesday it has signed an agreement to sell its unit Saab Automotive to Sweden's Koenigsegg Group AB, confirming an announcement in June, although government officials warn that more capital is needed before the deal can be closed.

GM said the deal, whose financial details were not disclosed, is subject to a funding commitment for Saab from the European Investment Bank, to be guaranteed by the Swedish government. The Swedish government is negotiating with Koenigsegg on a possible guarantee for a loan to Saab from the European Investment Bank.

The companies signed a stock purchase agreement that would give the tiny Swedish supercar maker 100 percent of Saab's shares, GM Europe said in a statement.

"This contract is an important step in the journey to a potential deal," GM Europe President Carl-Peter Forster said in the statement. "We will continue to work with all parties to define the final details and ensure a fast closure of the deal."

Koenigsegg spokeswoman Halldora von Koenigsegg told Reuters on Tuesday that the firm expected to close the deal within about a month, while GM said it saw the deal closing by the end of the year.

As part of the proposed deal, GM and Saab will continue to share technology and services for a set time period. GM did not say how long the two companies would work together. GM and Saab will use license and service agreements to manager their future relationship.