Germany would consider a temporary state-trusteeship for General Motors Corp.'s (GM) Adam Opel AG unit, if investors present detailed, feasible bids by Wednesday, Economic Minister Karl-Theodor zu Guttenberg said Thursday.

"And I emphasize the word 'if,'" zu Guttenberg said at a press briefing following a top-level internal meeting on Opel in Berlin, which included Chancellor Angela Merkel and Finance Minister Peer Steinbrueck.

In such a temporarily state-trusteeship of Opel, the company might get a credit line provided by state-owned bank KfW and state-owned Landesbanken of the states with Opel plants.

The two investors that have expressed interest in Opel include Fiat SpA (F.MI) as well as a consortium that involves Canadian auto parts maker Magna.

"It is important to know that until May 20 the two investors, or interested parties, want to provide their concepts, at least we hope for a more sustainable concept than the only very rough plan presented so far," he said. "On the basis of the sustainability of this plan, we will then decide what to do."

He added the government is striving for a trustee solution if a sustainable plan emerges.

"This solution must ensure that the negotiations will continue and secondly that tax payers' money won't be wasted," he said.

He said the trustee solution might be needed because "it is quite possible that there will be a fundamental decision in the United States within the next weeks regarding the future of General Motors, Chapter 11 is being discussed," he said.

Further, zu Guttenberg didn't rule out that there could be other potential investors for Opel.

-By Nikki Houston and Andrea Thomas, Dow Jones Newswires; +49-30-288-8410; andrea.thomas@dowjones.com