German Economy Minister Karl-Theodor zu Guttenberg has expressed himself to be unswayed by the merits of the three bids lodged for Opel Wednesday despite Fiat's unexpected submission of a revised offer at the end of the week. Fiat's new bid is now being examined in detail to see if it actually offers a more viable future for Opel.

Guttenberg told reporters today that Fiat's revised bid would be checked out to see "if they can stand up everything they say." News has also filtered through that Magna has also improved its bid, a source "close to the negotiations" told the Reuters news agency today. "There are indications that Magna has improved its offer," said the source.

Guttenberg has been tasked with finding a new investor for Opel as its parent company GM could plunge into the Chapter 11 bankruptcy process on June 1, the deadline set by the Obama Administration for the ailing American carmaker to come up with a viable restructuring plan. Three interested parties - Fiat, Magna International and RHJ International - all placed bids for Opel on Wednesday.

Today Guttenberg was highly dismissive of the three bids, saying "we still cannot be sure whether Magna, or Fiat, or Ripplewood will ensure that bridge loans won’t disappear into a black hole, that any further guarantees will be effective and that they’re really offering something more than high-minded romantic ideas." A successful bidder could unlock the doors to up to 7 billion euros of state aid. He also told the German newspaper Bild am Sonntag a similar story: "We need a high degree of certainty that the considerable sum of taxpayers' money we will have to put up is not lost. None of the three plans sufficiently meets these requirements at present."

Fiat raised its offer yesterday after it emerged that Magna had become the German government's favoured bidder. A meeting chaired by Chancellor Angela Merkel had decided to move forward for "concrete talks" with the Canadian automotive components and contract assembly firm as they believed this option presented the best route forward to developing new markets and that it also avoided "dependence on Fiat-Chrysler technology," according to comments made by Roland Koch, the Prime Minister of the state of Hesse, where Opel's Rüsselsheim headquarters are located.

Marchionne told Bild am Sonntag that the revised plan for Opel would see any job losses in Germany limited in number and all the plants would be kept open. "In the worst case a maximum of 2,000 jobs would be affected by the integration of Opel into a debt-free joint venture with Fiat,"

Another option for Opel now being considered by Guttenberg is a structured insolvency process. After expressing reservations about all three bids he said that "should those deficits remain, a structured insolvency would clearly be the better solution. That too could open opportunities for the future of Opel." Next week will be key in the timetable of resolving Opel's future. A further German government meeting will take place on Monday, again to be chaired by Merkel, with a strategy to resolve the situation expected to emerge in the following days.