The head of Sweden's influential IF Metall union urges US automaker General Motors to seriously consider Dutch sports carmaker Spyker's renewed bid for Saab Automobile.

"I understand the frustration felt by everyone who is dependent on Saab, to be thrown between hope and despair is terrible. GM must now respond with a serious examination of the new bid," IF Metall chairman Stefan Loefven said in a statement.

Spyker said Sunday it had made a new bid for Saab, two days after its American owners General Motors said it would close the loss-making unit.

"The Spyker leadership has submitted a renewed offer in the hopes of securing a future for Saab, its employees and the brand -- despite the announcement that the winding down of Saab would begin," the company said in a statement.

Spyker said it hoped "the renewed offer would remove each of the obstacles that were standing in the way of a swift transaction."

Loefven said the new bid "demonstrates there is a significant interest" in Saab, and called on Sweden's centre-right government to get involved in the talks with GM.

"It is now important that the talks with GM be carried out at the highest level. It is our opinion that this is a matter for the prime minister and enterprise minister," he said.

Spyker chief executive Victor Muller said in the statement he was confident a deal could be done by the December 31 deadline set by GM to complete the sale.

Spyker's new offer remains valid until 2200 GMT on Monday.

GM has been trying to sell the loss-making unit since the start of the year.

Saab employs about 3,400 people in Sweden. According to media reports, Saab's closure could lead to more than 8,000 job losses, including subcontractors and others dependent on the carmaker.