The chief executive of General Motors’ European operations resigned yesterday following the American car company’s decision to retain ownership of Vauxhall and Opel.

Carl-Peter Forster will be replaced temporarily by Nick Reilly, the British head of GM’s international operations. Fritz Henderson, GM chief executive, said that an external search for a permanent chief executive would begin immediately.

He said no other management changes were being considered for the European operations and that proposals for the future of Opel and Vauxhall would be finalised next week.

Mr Forster, who has been GM’s top European executive since June 2004, backed the Magna deal before the sale was abandoned.

“Such a sudden shift isn’t comprehensible,” Mr Forster said on Wednesday about GM’s decision not to sell the units to Magna. “I hoped that it would have come to a much different outcome.”

Mr Reilly runs the Chevrolet brand, which has long been favoured by Detroit over Opel.

After his spell at Ellesmere Port, in Cheshire, he was sales and marketing chief for GM Europe in Zurich before moving to Asia to run GM operations there. He is thought to want to retain the bulk of Vauxhall’s 4,500 workers.

An Opel union representative said: “Reilly is more than capable — someone we’ve got some respect for, since the one thing he did have was integrity. But I don’t think he’s the sort of person who would make a decision based with any affinity for any one country.”

As a result, Magna’s plans that would have largely spared cutting jobs in Germany look set to be abandoned.

Angela Merkel, the German Chancellor, had invested much time, political capital and state aid — a promised €4.5 billion (£4 billion) — to seal the Opel sale to Magna, the Canadian carparts maker. It is feared that as many as 10,000 of the 25,000 Opel jobs in Germany could go in a GM restructuring plan that, in the words of IG Metall union leaders, takes “no heed of personal pain, pride in the job or the future”.

Der Spiegel reported that Mr Reilly would cut thousands of posts: “The appointment of this manager is a provocation for the German carmaker, because up to now he was responsible for the Asia business and the cheap marque Chevrolet, which made life for Opel in Europe much harder. While GM expanded Chevrolet into new growth markets, Opel was downgraded to a regional European brand. Opel staff will not be impressed with this news.”

There were reports that Bob Lutz, 77, an industry veteran with vast experience on both sides of the Altantic at BMW, Ford, Chyrsler and GM, would replace Mr Forster as head of Opel’s supervisory board.

Meanwhile, Philip Gordon, America’s Assistant Secretary of State, said yesterday that the Obama Administration had played no part in General Motors’ decision to keep its European division. GM announced its decision on Tuesday, just after the departure from Washington of Mrs Merkel.

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