"Under a unifed management company the 10 brands are to stand alongside each other in the final structure, whereby the independence of all the brands, and thereby also that of Porsche, will remain," the Porsche Holding statement said.

With details still sketchy, the German Press Agency dpa learned that a capitalisation increase may be sought in order to reduce debts, while a joint VW-Porsche working group is to work out the structure of the future concern over the next four weeks.

Current large-scale stakeholders such as the state of Lower Saxony and employee groups would have a "major" role in such talks.

In an initial reaction, Lower Saxony Premier Christian Wulff said he was prepared for such talks. The state has a blocking minority stake in VW, which is based in the city of Wolfsburg and so has veto rights over any major decision.

"We are ready for talks, which must quickly be carried out with all the parties - Porsche, Volkswagen, worker representatives and the state of Lower Saxony," Wulff said.

Porsche, after gaining a 51 percent stake in VW, is now struggling under debts of $9 billion ($12.7 billion), in turn derailed the company's initial aim of boosting its stake in Europe's largest automotive group to 75 percent.

With Wednesday's announcement, that aim of a 75 percent stake was finally laid to rest, industry analysts said.