Canadian auto supplier Magna International aims to close a deal with General Motors over its Opel unit in September, Magna's co-Chief Executive Siegfried Wolf said Wednesday.

The comments come in the wake of a deal struck over the weekend between Magna, General Motors and the U.S. government for the sale of parts of its Opel unit.

German carmaker Opel's Chairman Carl-Peter Forster said a lot of details of Canadian auto parts group Magna International's deal to buy the company still needed to be clarified.

The chaiman's comments come in the wake of a deal struck over the weekend between Magna, General Motors and the U.S. government for the sale of parts of its Opel unit.

The future of General Motors Europe's plants was uncertain, Opel works council head Klaus Franz said. Negotiations over Opel's plants including Britain's Luton, Belgium's Antwerp and the German city of Bochum would be tough, Franz said.

The Magna deal included bridge financing worth 1.5 billion euros ($2.14 billion) and an interim solution in the form of a trustee model for Opel.

Initially, Magna had said it would loan Opel 300 million euros to cover short-term liquidity needs, but German Finance Minister Peer Steinbrueck said on Tuesday that the deal had changed and Magna would not be part of the bridge financing.

Magna will hold 20 percent of the new company, and Russia's Sberbank will hold 35 percent. Franz said he expected Sberbank to pool its votes together with Magna's.

(Reporting by Christiaan Hetzner; Writing by Maria Sheahan)