The manufacturer of the 911 sports car currently owns 31 percent of the shares in VW and plans to raise its stake to more than 50 percent at an unspecified point in the future.

Porsche said it had called on Volkswagen to propose changes to its articles of incorporation at a shareholders' meeting April 24 and to eliminate clauses deemed illegal by a European Union court in October.

The amendments would include annulling the right of the German government, and the state of Lower Saxony which holds a 20 percent stake in VW, to send representatives to the car maker's supervisory board.

Porsche also said the VW corporation bylaws should remove a clause that caps voting rights at 20 percent regardless of the number of shares owned by an investor.

A clause that defines 80 percent of VW shares represented at the general assembly as a "qualified majority" vote should be reduced to 75 percent, Porsche said.

A qualified majority vote from the assembly is required on certain strategic issues, effectively giving Lower Saxony a veto over some decisions.

Porsche said it wanted the amendments included in the assembly agenda because VW had not implemented a ruling from the European Court of Justice.

The court ruled that certain clauses of the so-called Volkswagen Law, passed by the German government in the 1960s to protect the carmaker from hostile takeovers, violated EU laws on free movement of capital.

Porsche urged the German government to scrap the VW law altogether, after officials said they were working on a new draft that would pass EU muster.

The luxury sports car maker has called in the past for the government to begin considering VW as "a normal company."