DETROIT (AFP) - Spkyer has the money to buy Saab and GM is "considering" its offer very seriously, the head of the Dutch sports car maker said Tuesday.

GM has begun the orderly wind down of Saab and the fate of the Swedish car maker seemed sealed last week when GM chief Ed Whitacre said the US auto giant had done everything it could to find a buyer but so far nobody had come up with the money.

But Victor Muller, founder and chief executive of Spyker Cars said the death knell had not yet rung.

"We have shown Mr. Whitacre the money," said Victor Muller, founder and chief executive of Spyker Cars.

"We are absolutely definitely negotiating in good faith with GM to buy Saab," Muller told a conference hosted by Automotive News in Detroit.

"They are considering offers very, very seriously."

Muller said he is "not very concerned about all the steps that are being taken with the wind down" because they are consistent with the plan GM set forward after a deal to sell Saab to Swedish sportscar maker Koenigsegg.

General Motors announced on December 18 that it would wind down the brand which has barely turned a profit during two decades under GM ownership, but several groups have since made last-ditch bids for it.

They include Spyker, a group comprised of Formula One boss Bernie Ecclestone and Luxembourg investment firm Genii Capital, and a Swedish group fronted by the former chief executive of German truck manufacturer MAN and a former politician.

"If the sale of Saab doesn't generate more than the wind down scenario costs, for them it's clearly not attractive," Muller said.

"So it was my job, our job, at Spyker to put forward a proposal that is attractive enough for them to reverse the position."

Muller declined to provide details of the offer.

Several thousand people gathered for a demonstration in Sweden on Tuesday to call for Saab to be rescued from its owner GM's plan to shut it down, a union official said.

Saab, which employs 3,400 people in Sweden, is one of four storied brands being shed by GM as part of a massive restructuring effort that began in 2005 and accelerated last year when the largest US automaker went bankrupt.

Analysts have warned that some 8,000 jobs could be lost with Saab's closure.