General Motors is understood to be preparing to part with a controlling stake in Opel/Vauxhall for nothing and will look to invest in a new company formed from its European business, according to reports.
Potential buyers are expected to have up to three weeks to indicate their interest. It is believed that an investor will be asked to pay at least $652m (440m) in equity, with the money to be put directly into Opel/Vauxhall.
The struggling car maker is also preparing to offload Saab, its premium Swedish marque that filed for creditor protection earlier this year.
GM has lost over 55.7bn since 2005 and has been handed $13.4bn (9.2bn) in loans from the US government.
It is also seeking a further $16bn (10.9bn) from the government. It has been given until June 1 to come up with a restructuring strategy that will cut costs and debt levels.
Last week Vauxhall announced its intention to pull out of the British Touring Car Championship next year