A joint statement from Zurich-based GM Europe, German-based unit Opel and employee representatives said it is necessary to ensure that the European business stands on a 'sustainably healthy financial basis.'

It said that, if it makes sense for the 'sustainable success' of GM Europe and Opel, management is 'prepared to talk with third parties about partnerships and participations.'

It said management and employee representatives would start immediately to discuss a restructuring process and address how layoffs and plant closures might be avoided.

'Both sides -- employees and management of GME and Opel -- are of the firm opinion that Opel, as the core brand of the European GM business with a successful model policy, has a good future,' assuming financial issues can be resolved, the statement added.

GM Europe officials met with the German government in November to discuss possible loan guarantees, but no decision has yet been made. Chancellor Angela Merkel made clear Wednesday that it is up to the company to make the next move.

'A concept must be put on the table that shows what positive prospects for Opel could look like,' Merkel told reporters in Berlin.

'At the moment, politicians can't do anything because the necessary concepts from Opel are not available,' Merkel said. 'And that can't happen without the parent company in Detroit.'

Opel employs approximately 25,000 workers in Germany, and also builds cars in Belgium, Poland, Portugal and Britain. It is the third-most popular brand in Germany, behind Volkswagen and Mercedes-Benz.