The move is prompted by a sense of urgency concerning the situation at Opel, which employs around 25,000 people in Germany, daily Financial Times Deutschland reported.
To date, Berlin has only evoked the possibility of providing loan guarantees to help Opel obtain critical financing as GM goes hat in hand to the US government for aid as well.
Opel supervisory board member Armin Schild has estimated the German car maker needs at least €3.3 billion ($4.2 billion) in cash to survive.
The company will go bankrupt by May or June if no state aid is forthcoming, mass circulation daily Bild reported Saturday.
Some politicians would like the government to take a direct stake in Opel, but the idea is subject to debate within Germany's broad left-right ruling coalition.
Berlin has told Opel to present a viable business plan if it wants public aid, which the company will likely do on Friday.
A separation from GM is also under consideration.
General Motors has opened the door to getting rid of Opel as part of a broader restructuring plan which includes laying off 47,000 workers worldwide, slashing production and closing plants.