MOSCOW (AFP)--Russian state lender Sberbank said Friday that a deal to buy Adam Opel GmbH with Canada's Magna International from bankrupt U.S. giant General Motors Corp (GMGMQ) had to meet Russia's conditions or it could fall through.

"The new conditions have to satisfy the bank and the Russian Federation. If the conditions suit us then we can close this deal," Sberbank chief German Gref was quoted by RIA Novosti news agency as saying at a press conference.

Asked about the possibility of the negotiations falling through, the deputy head of the bank, Denis Bugrov, said: "I am not excluding it."

If there is an agreement, Gref said the deal could be signed in September.

The German government last month announced a rescue plan for the German auto unit Opel under which 55% of the company would go to Canadian auto parts manufacturer Magna International and Sberbank while 35% would stay with GM.

Negotiations have since stalled as GM is trying to raise the price of the deal.