Dutch auto maker Spyker is optimistic about its chances of buying General Motors' Swedish unit Saab and expects a response from GM this week.

"We expect an answer this week ... I am very optimistic," Spyker chief executive Victor Muller told the Swedish newspaper Svenska Dagbladet.

The paper last week said GM would not consider a renewed bid for Saab from Spyker and was planning to shut down the troubled Swedish brand.

Spyker renewed its offer on December 20, two days after General Motors said it wanted to close down Saab.

Swedish press reports have said GM agreed to re-open negotiations on the sale of Saab to Spyker after the withdrawal of two of Spyker's Russian investors.

GM was reportedly concerned about the transfer of technical know-how to Russia.

Svenska Dagbladet reported last week that Spyker's main investors, Vladimir and Alexander Antonov, with a 29.3 percent stake in the company, were no longer behind the Dutch group's bid for Saab.

Syker's second-biggest investor, Abu Dhabi state investment fund Mubadala Development, which owns 22.7 percent, was likewise no longer involved, according to the report.

Instead, an unidentified Dutch billionaire was putting up the money, the paper said.

General Motors has said it wants to sell Saab, which employs 3,400 people in Sweden, before the end of the year.