UPDATE 1-SolarWorld CEO says Opel must be freed from GM

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BERLIN, Nov 20 (Reuters) - German automaker Opel must be freed from the constraints of its U.S. parent company General Motors GM.N if it is to develop cars of the future, SolarWorld (SWVG.DE) Chief Executive Frank Asbeck told German radio on Thursday.

SolarWorld shocked markets on Wednesday when the 10-year old solar energy company unveiled plans to acquire venerable Opel, which has come under financial pressure because of the woes of its U.S. parent and a sharp downturn in demand for cars.

"I see a need to overhaul our manufacturing sector. Just like we have seen in the alternative energy area, the auto industry must be overhauled. That means we need to build cars of the future -- electric, hybrid engines, this can't be left to the Japanese," Asbeck told Deutschlandfunk radio.

"This is already in the heads of the developers at Opel, but they must be freed from the restraints of General Motors," he added.

GM Europe was dismissive of SolarWorld's overture on Wednesday and said Opel, which is seeking about 1 billion euros in guarantees from the German government, was not for sale.

But Asbeck said he had detected mixed signals from GM, which itself is lobbying for a government rescue in the United States.

"There are contradictory signals. We've seen different comments from the headquarters and from Ruesselsheim," Asbeck said, referring to Opel's main site in Germany.

"This shows that a big company has a lot of different opinions, that it can be quite contradictory and also slow. But we may need a quick rescue."

Asbeck reiterated that he was serious about acquiring Opel, a prospect many analysts have dismissed as far-fetched, and said he was not concerned about a sharp drop in his company's share price in response to the bid plans.

(Writing by Noah Barkin; Editing by Erica Billingham)