Spyker Cars' renewed approach came just two days after last-ditch talks with GM over a rescue of the loss-making Swedish manufacturer collapsed.
On its website, GM said that since Friday's announcement that it would start the orderly wind-down of Saab, it had received inquiries from several parties.
We will evaluate each inquiry. We will not comment further until these evaluations have been completed, GM said in a statement.
Abandoning the 60-year-old Swedish auto brand would eliminate 3,400 jobs in Sweden and drop 1,100 Saab dealers.
Spyker said on Sunday it has submitted a renewed offer including an 11-point proposal addressing issues that arose during the due diligence process.
We're very confident we have put forward a proposal that can convince GM in time, Spyker Cars Chief Executive Victor Muller told Reuters in a telephone interview.
The jury's still out. We will see what happens next.
Spyker Cars said the new offer eliminates the need for a European Investment Bank (EIB) loan approval prior to year end, which would allow the deal to be concluded within GM's deadline.
Muller said the financing for the Saab offer was in place, but did not reveal any further details.
GM -- which had previously entered talks with Spyker after a deal with Swedish luxury car builder Koenigsegg collapsed last month -- had set an original deadline of December 31 to seal a deal.
Spyker's renewed offer is valid until 5 p.m. EST on Monday, December 21.
We have made every effort to resolve the issues that were preventing the conclusion of this matter and we have asked GM and all other involved parties to seriously consider this offer, Muller said in a statement.
The primary backers of Spyker Cars -- which last year sold 43 cars at prices of at least 200,000 euros ($287,800) -- include Russian banking tycoon Vladimir Antonov and his Convers Group, which has a stake of almost 30 percent in the firm.
Jeroen Willard, an analyst at Dutch brokerage AEK, has said that for Spyker -- which has struggled for years -- to finance the deal it would likely issue shares to its Russian backers.
Spyker Cars said if a deal could be agreed, Saab would provide it a global distribution network, production facilities and solid engineering, sourcing and R&D, while Saab would receive financial backing to compete as a global brand.
(Reporting by Aaron Gray-Block, editing by John Stonestreet and Matthew Lewis)