BERLIN (Reuters) -- General Motors Co. will return the money it was loaned by Germany to help Opel, German Economy Minister Rainer Bruederle said today after the U.S. carmaker decided to keep its European unit.

"We will the get the taxpayer's money back," Bruederle told reporters in Berlin, calling GM's behavior over the future of Opel "totally unacceptable."

GM's board had previously opted to sell a 55 percent stake in the money-losing Opel unit to Canadian group Magna International Inc. and its Russian partner Sberbank after seven months of talks.

Juergen Reinholz, economy minister of Thuringia, one of the states in Germany that hosts Opel plants, said GM had signaled it would pay back a 1.5 billion euro German bridge loan for Opel by the end of November.

GM only owes German state and federal governments about 900 million euros because it has already paid back some of the bridging loan it received, Dirk Pfeil, a member of the trust overseeing Opel, told Reuters on Wednesday.

Pfeil said that Opel had borrowed a total of 1.1 billion euros from the state and federal governments -- less than the maximum 1.5 billion euros they had made available. Pfeil said that 200 million euros had already been repaid.

No insolvency risk

GM also has made clear insolvency is not an option for Opel, a German government spokesman said on Wednesday.

"GM has said that is not an option," government spokesman Ulrich Wilhelm told a regular news conference, when asked about the possibility of insolvency.

In addition, GM has promised to present Germany a restructuring plan for Opel soon, Economy Ministry spokeswoman Beatrix Brodkorb said on Wednesday.

A government spokesman added that he understood GM's decision not to sell Opel was final.