Volkswagen AG, Europe's biggest carmaker, and Porsche SE should sell a stake in the company resulting from a merger to a foreign investor, according to Germany's Lower Saxony, the VW shareholder with veto power.

The German state has no intention of increasing its 20 percent stake in VW after the carmaker's planned combination with Porsche, Lower Saxony Prime Minister Christian Wulff said late Monday in Volkswagen's hometown of Wolfsburg. About 30 percent of the new company will be available to investors once the owners sort out its structure, he said.

"This is a considerable portion that would be open to many possible investors," Wulff, 49, said. "We're open to those investors. Lower Saxony's role will remain the way it is now."