Germany reportedly wants takeover plans of Adam Opel GmbH from leading bidders Fiat Auto Group and Magna International Inc. by May 20, and has begun formulating a government plan for temporary financing to back the auto maker if parent General Motors Corp. files for bankruptcy.

“We are dealing with two potential investors at the moment, with Fiat and Magna,” Germany’s Economy Minister Karl-Theodor zu Guttenberg says after a meeting with colleagues on the topic earlier today, Reuters reports.

“By May 20, the two investors want to present their proposals. We are hoping for a more sustainable concept than has been presented to us so far.”

Fiat CEO Sergio Marchionne is looking to add Opel to his empire after gaining clearance last week from a U.S. bankruptcy judge to potentially build a future stake of as much as 35% in Chrysler LLC.

He also wants GM’s Latin American operation, but the Detroit auto maker reportedly is resisting giving up the profitable unit without a major stake in the new global automotive conglomerate Marchionne intends to spin off from parent Fiat SpA after gaining Opel.

The Financial Times says talks between Fiat and GM, which dissolved an engine partnership earlier this decade due to engineering differences, have become snagged over the Latin American unit and GM’s future stake in Fiat/Opel.

Opel’s labor group also appears to be getting cold feet over the deal with Fiat, fearing job losses. Opel employs 25,000 people in Germany.

Magna publically disclosed its intentions to gain a stake in Opel last week, but since has declined further comment. Russian auto maker OAO Gaz confirmed Tuesday it would like to join with Magna on joint venture for manufacturing cars in Russia if the parts maker is successful in its bid.

Belgian holding company RHJ International also has shown an interest in Opel, according to news reports, but Guttenberg confirms only two bidders for Opel at this time.

GM, surviving on $15.4 billion in U.S. taxpayer loans, has its own deadline to meet. The auto maker must restructure its business by a government-imposed deadline of June 1 or enter bankruptcy.

The financing deal under way by the German government would ensure Opel takeover talks continue and taxpayer money is not wasted if GM enters Chapter 11 in the U.S., Reuters reports.