U.S. carmaker General Motors could cut between 9,000 and 10,000 jobs as part of a restructuring of its European operations, Nick Reilly, interim head of GM's European business, said on Tuesday.

The company must reduce its production across Europe by between 20 and 25 percent as part of the 3.3 billion euro ($4.9 billion) plan, he told a news conference in London.

Details of where and when the jobs will be lost have yet to be decided, he added. He would not say how much of the funding will come from governments and how much from the company.

It could involve closing a plant, he said. We haven't 100 percent decided.