-- As many as 10,500 jobs at Adam Opel GmbH, or about 20 percent of the work force, may be eliminated as part of a restructuring plan for the German carmaker, said the co-chief executive of Magna International Inc., one of the prospective new investors in Opel.

The cuts outlined Monday by Siegfried Wolfof Magna were broadly in line with the job reductions described in June when Magna outlined its proposal for Opel, one of General Motors Co.'s overseas subsidiaries.

Wolf said about 4,500 of those cuts could be in Germany, which is home to Opel's headquarters in Rüsselsheim and half of its 50,000 employees across Europe.

His comments seemed aimed at quelling concerns among other European governments that Germany had offered Opel loans in exchange for preserving German jobs.

Opel's top labor representative, Klaus Franz, the vice chairman of the carmaker's supervisory board, said Wolf's remarks did not come as a surprise.

"Unions can't be comfortable with job cuts. But we've known these figures from the beginning," said Franz, who strongly backed a joint bid for Opel from Magna and its Russian partner Sberbank.

"We know Opel Europe must be restructured," he said. "These are the brutal facts, and we understand that."

But he said Magna had given assurances that the job cuts would be achieved through early retirements and buyout offers, with no forced redundancies.

Politicians in Europe, particularly in Belgium where Opel's Antwerp plant appears threatened, have asked the European Commission to ensure that Germany hasn't secured protection for its workers in exchange for loans to Opel. The German government has extended $2.1 billion in bridge loans to Opel and offered another $6.4 billion in loan guarantees if GM agreed to the Magna-Sberbank offer.

In a conference call in Canada, Magna's other chief executive, Don Walker, said Magna might dispatch some executives to work at Opel, but said they would not be employed then by Magna.

Magna said it expects Opel to start repaying its loans in 2015, but declined comment on comments last week from a senior GM official that Opel was expected to return to profit in 2011 under the Magna-Sberbank plan. Opel has been losing money for several years in the cutthroat European market.

Last week, General Motors Co. agreed to sell 55 percent of the unit to Magna and Sberbank in a 50-50 split. GM will keep 35 percent, the biggest single stake in Opel, and Opel workers will hold 10 percent.

The deal, announced Thursday, still hinges on conditions that could take weeks or months to work out, such as final agreement for government financing and union support for what could be painful cuts. Chief GM negotiator John Smith indicated then that the Antwerp plant could be wound down.

Belgium has asked the European Union to investigate the deal to make sure Germany is not violating anti-trust rules.

Magna had promised to keep Opel's four plants in Germany -- Eisenach, Bochum, Russelsheim and Kaiserslautern -- open.

Opel has been losing money for years. Its European operations, which include Opel, Vauxhall and Saab, posted an operating loss of about $2 billion in the first quarter of 2009 and a total of nearly $3.7 billion for 2006-2008. Analysts say most of the losses can be attributed to Opel and Vauxhall.

GM had sought to unload Opel since it ran into severe financial trouble late last year, seeking state help in November 2008. Industry analysts say the unit has too many employees and too much factory capacity for its sales level and its costs are too high.