Germany has a plan to protect the assets of carmaker Opel from creditors if its U.S. parent General Motors is forced into bankruptcy next month, German Economy Minister Karl-Theodor zu Guttenberg said in an interview with a German weekly.

In the interview with Der Spiegel magazine published on Saturday, Guttenberg urged those investors interested in acquiring GM's European operations, including Opel, to move fast given the threat to the U.S. parent.

We want rapid, reliable information from the investors because we can't rule out that GM in the United States will have to file for bankruptcy at the beginning of June, Guttenberg said.

This could come at the same time interested parties are finalizing a deal with GM on Opel. Then we need to ensure Opel assets are protected from creditors. We are preparing for this scenario.

Italian carmaker Fiat is seeking a three-way merger with Chrysler and GM's European operations. Austrian-Canadian car parts maker Magna is also interested in pursuing Opel, most likely in concert with Russian investors.

Guttenberg said in the event of a GM bankruptcy, Opel assets could be handed over to a trustee who would ensure the interests of creditors. At the same time, a consortium of banks could provide Opel with bridge financing.

In this way the firm's continued existence would be assured until a final deal (with investors) was reached, Guttenberg said.

A senior German official told Reuters in Abu Dhabi, where Guttenberg was traveling on Saturday, that the government could also provide bridge financing for Opel.

In the magazine interview, however, Guttenberg ruled out the government taking a stake in the carmaker to help tide it over.

(Additional reporting by Gernot Heller in Abu Dhabi; Writing by Noah Barkin, Editing by Peter Blackburn)