Spyker has extended the deadline for its offer to buy Saab, raising hopes that talks with GM are progressing, according to reports.
However, the Swedish government has warned that there is only a "very, very slim" hope of saving Saab.
Spyker had previously given GM until 10pm tonight UK time to consider its latest proposal, but sources have now said that the deadline has been extended indefinitely as negotiations continue.
Unions and Swedish government officials held emergency talks today in Saab's manufacturing hub of Trollhatten to discuss the likely closure of Saab.
Sweden's enterprise minister, Maud Olofsson, said: "We hope, naturally, that even if it is a very, very slim thread of hope, there is a chance of finding some kind of solution to the question of Saab."
The new Spyker offer does not require accelerated approval of a loan from the European Investment Bank, which was a sticking point.