The final decision to take over Adam Opel AG remained open Thursday after Germany's Economy Ministry said it isn't closing talks with alternate bidders to Magna International Inc. (MGA), the Canadian auto parts supplier the German government has named as the preferred bidder.

The German government chose Magna's consortium last week and pledged to provide EUR1.5 billion in bridge financing to keep the Ruesselsheim-based auto firm afloat following the bankruptcy filing of parent General Motors Corp. (GMGMQ) in the U.S.

Magna has said it expects to sign off on the deal in four to five weeks and aims for Opel entry in September.

But Economics Ministry State Secretary Jochen Homann said Thursday the government can't rule out the possible failure of Magna's offer.

"There is always a risk that it won't be successful in the end," Homann said, echoing remarks by Economics Minister Karl-Theodor zu Guttenberg who cautioned Wednesday that Magna's offer is non-binding.

Homann confirmed that China's Beijing Automotive Industry Holding has now presented a plan for Opel as well, and voiced interest in a second chance, should the deal with Magna turn sour.

Italian automaker Fiat SpA (F.MI) had launched a rival offer for Opel, as did U.S.-based investment firm Ripplewood.

Fiat, which was Magna's last remaining contender for Opel, skipped a decisive meeting with the German government last Friday, citing a lack of transparency over Opel's financial condition. But it said it remains interested in forging an alliance with Opel.

Speaking at the sidelines of a conference in Milan, Italy's Industry Minister Claudio Scajola said Thursday that recent comments from the German government "may mean that six months from now" Fiat's bid will be "reconsidered".

Separately, Magna's Russian ally OAO Sberbank (SBER.RS) Thursday said it would sell its stake in the German automaker if the consortium's deal goes through as planned. Sberbank's Chief Executive German Gref said it will sell its stake in Opel, potentially to a Russian investor, as the state-controlled bank is not planning on becoming a strategic investor. Still, he said the takeover should be fully completed by autumn.

Magna's consortium comprises Sberbank as well as troubled Russian automaker OAO GAZ Group (GAZA.RS).

"After we finish structuring the first part of the deal, we will think about who could be a strategic partner," Gref told journalists in St. Petersburg.

Magna and Sberbank will commit some EUR500 million that will be divided proportionally to their stakes, Gref said.

Under the plan, which is backed by Opel's works council, GM would retain a 35% stake in the company. Sberbank would take a 35% stake as well, with Magna holding 20% and Opel's employees with 10%.

The chief goal behind the deal is "to help restructure Russian assets," which are affected by GM's bankruptcy, Gref said. He added that the deal includes Russian rights to Chevrolet, the best selling foreign brand in the country.

In an interview with German tabloid Bild, Opel's supervisory board chairman Carl-Peter Forster said he is optimistic that the company can return to profitability before 2013. "All of my ambition is awakened to prove the opposite to Mr. Stronach," Forster is quoted as saying, referring to remarks made by Magna chairman Frank Stronach saying Opel will only be able to make a profit in four years' time, or 2013.

Company Web site: www.opel.com

-By Christoph Rauwald, Dow Jones Newswires; +49 69 29 725 512; christoph.rauwald@dowjones.com

(Andreas Kissler, Paola Longo and Lidia Kelly contributed to this article)