BERLIN, May 24 (Reuters) - Germany's Economy Minister, Karl Theodor zu Guttenberg, said on Sunday the three bids for General Motors' unit Opel were still unacceptable because too much potential financial risk would lie with the government.
Speaking to journalists ahead of a meeting on Monday with Chancellor Angela Merkel and top ministers, Guttenberg said bids from Magna International, Fiat and industrial holding company RHJ International had to be improved.
"The plans are not yet at a level where we would have sufficient security," Guttenberg said. "They need to be improved quite considerably."
Guttenberg said Fiat had "hinted" it would be willing to take a share of the risks. He said he expected Magna to put forth "considerably improved" plans.
Guttenberg reiterated that a controlled insolvency could not be ruled out. "We obviously want to avoid that. But on the other hand we can't squander billions of euros in taxpayer money."
Both General Motors and the German government are in a race against time to finalise a sale of Opel, which is headquartered in Ruesselsheim near Frankfurt.
The U.S. government has given GM until June 1 to restructure its operations and prove it can be viable without state aid, or face probable bankruptcy.
The decision on who gets Opel will be taken by GM but the German government will also play a big role because it would likely supply billions of euros in financing guarantees. (Reporting by Andreas Moeser; writing by Erik Kirschbaum; Editing by Dan Lalor)