German carmaker Opel and its U.S. parent General Motors
GM Europe President Carl-Peter Forster had previously said Opel and UK-based Vauxhall unit would have an acute liquidity problem from next quarter.
GM Europe submitted a rescue plan for Opel last month under which Opel and Vauxhall would be partly spun off into a new subsidiary. It said the independent unit would need 3.3 billion euros ($4.3 billion) in state aid.
German Economy Minister Karl-Theodor zu Guttenberg met with GM's Chief Executive Rick Wagoner on Monday night and said it was essential for GM to find a private investor.
According to Woehrl, Guttenberg's visit to the United States earlier this week had moved the Opel issue a step forward. She added, however, that some questions remained open.
Germany is open to the possibility of helping Opel but has said it needs to be sure no state support would find its way to parent company GM, which is seeking more bailout help from the U.S. government to survive.
Opel works council head Rainer Einenkel said on Wednesday it was now the duty of the German government to help Opel.
The German government is now under an obligation to do something. It should no longer find excuses for a way out, Einenkel told NDR Info radio.
He said the government could provide loan guarantees in order to attract investors. A German association of Opel dealers is due to meet on Thursday to discuss the possibility of investing in Opel to secure their business.
Norbert Reithofer, chief executive of BMW
(Reporting by Gernot Heller and Angelika Gruber, writing by Paul Carrel and Marilyn Gerlach)