BERLIN, Germany - Chinese carmaker BAIC has proposed taking a majority stake in GM's European arm Opel with a bid worth 660 million euros, a move that could boost negotiations for the unit, reports said Sunday.

BAIC submitted a non-binding offer for GM's German-based unit Opel late Thursday, just before a deadline for prospective buyers, according to China's Guangzhou Daily newspaper, the Financial Times and Dow Jones Newswires.

Beijing Automotive Industry Corp.'s offer was said to be worth 660 million euros (S$1,343 million dollars).

German newspaper Frankfurter Allgemeine Zeitung reported that BAIC had sent a letter to several members of the German government proposing to take a 51-percent stake in Opel with state guarantees of 2.64 billion euros.

In the letter, BAIC chief Xu Heyi pledged "no Opel factory in Germany will be closed," though job losses were not ruled out, the paper said.

The Chinese company's offer could put pressure on negotiations already underway for Opel.

Russian state lender Sberbank is also in the bidding in partnership with Canadian auto parts manufacturer Magna International.

The German government in May announced a rescue plan for Opel in which 35 percent of the firm would go to Sberbank and 20 percent to Magna, but talks have since become bogged down.

According to the FT, RHJ International, a Brussels-based industrial holding linked to US buy-out group Ripplewood, has also made a non-binding offer.

Fiat is also interested in Opel, but has pledged no cash for the stake.

The head of GM Europe has said he hopes Opel will be bought by Magna by mid-July, and that the Canadian firm has a "considerable lead" on other possible buyers, Frankfurter Allgemeine Zeitung reported.

"The only thing remaining is for the details to be agreed" between the two businesses, Carl-Peter Forster told the newspaper.

Forster also said the fact that "there are other candidates that stimulate the process can only help from the point of view of the seller, GM," the paper reported.