At the same, the U.S. automaker cast around for fresh options for Sweden's loss-making Saab after the collapse of its sale to luxury carmaker Koenigsegg added a new dimension to its tortuous European restructuring plans.
GM this month backtracked on months of talks to sell a majority stake in Opel to a Russian-backed group led by Magna International
Acting GM Europe head Nick Reilly said 50-60 percent of the proposed job cuts in Opel had been earmarked for Germany.
He said he hoped to wrap up details -- including the uncertain future of the Belgian plant in Antwerp -- during talks with labor leaders that he said were unaffected by the turmoil surrounding Saab.
Opel's top union boss, Klaus Franz, accused GM of sacrificing German jobs by shifting production of the Astra Caravan model to Britain's Ellesmere Port plant to secure UK state aid.
He also urged GM to expand the model range and powertrain options and export Opels as a way of saving jobs preventing GM from draining funds from Opel to Detroit.
Reilly said he was optimistic about prospects for getting both labor concessions as well as state aid from countries with Opel plants, which also include Britain, Spain and Poland.
Upto now, we have had a reasonably good response, not in terms of actual numbers but in terms of willingness, from everybody we've spoken to, including in Germany, he said.
The U.S. automaker emerged from bankruptcy in July and is fighting to redefine itself after crushing debt and legacy costs saw it fall victim to the worldwide auto crisis last year.
Some analysts say the European market in which Opel and Saab operate has as much as 20 percent too much capacity.
SAAB'S UNCERTAIN FUTURE
On Tuesday GM's deal to sell Saab to niche luxury carmaker Koenigsegg, backed by China's BAIC, collapsed after the buyer walked away.
Trolhattan, Sweden-based Saab has not made a profit since 2001 but Joran Hagglund, state secretary at Sweden's Industry Ministry, said GM appeared to still harbor hope of being able to sell it.
The Swedish government had effectively ruled out a state bailout of the 60-year-old auto brand, saying on Tuesday that a private buyer was the only option for Saab.
GM's board meets next week and the question of what to do with Saab will lead the agenda, a person with direct knowledge of the situation said on Tuesday.
No other bidders have so far emerged, meaning GM's only options would be to restart the sale process or to wind down the business, the more likely option, the person said.
BAIC, which had been part of the Koenigsegg-led consortium negotiating for Saab, said it was studying its options. Analysts said it was unlikely to bid for the whole of Saab alone, but might buy some of the assets.
(Additional reporting by Christiaan Hetzner, Maria Sheahan and Michael Shields in Frankfurst, Nick Vinocur and Simon Johnson in Stockholm and Doug Young in Hong Kong; Writing by Helen Massy-Beresford; Editing by David Cowell)