General Motors has said it is still in talks with potential buyers for its German Opel unit.

“GM remains engaged in discussions with the interested buyers, the German government and labour leadership, and any solution must be suitable for all vested partners,” GM said in a statement.

Credit lines worth EUR1.5bn extended by German federal and state governments will last until around January next year, according to economics minister Karl-Theodor zu Guttenberg.

He has opposed suggestions for a partial nationalisation of Opel, adding the government continued to work for an investor solution, Dow Jones reported.

According to a letter seen by the news agency, Opel’s management has asked all parties to work toward finding a solution before the Frankfurt motor show which begins on 17 September. Opel managing director Hans Demant wrote: “We need this most important automotive show to position ourselves for the future.”

The German government has lobbied hard for a bid by a consortium led by Magna International though the GM board wants a bid from RHJ given equal consideration.

German politicians set their preference for Magna “far too soon,” Fred Irwin, chairman of the trusteeship that will make the final decision on Opel’s future, told Dow Jones Newswires.

Once GM has selected a preferred bidder and the government has commented, the trustees will make a final decision.

Separately, zu Guttenberg told a German newspaper it was “hardly realistic” for GM to hold onto Opel.

Guttenberg also told the Frankfurter Allgemeine Zeitung that Opel bidder Magna still needed to clarify certain aspects of its offer for Opel, Reuters reported.