Winfried Vahland, a company veteran and currently CEO of Volkswagen's subsidiary Skoda, resigned from his post on Wednesday after more than 25 years at Europe's biggest carmaker.

Vahland had been recently appointed as head of VW's North American division as part of a restructuring plan pushed by the carmaker's new CEO Matthias Müller.

However, differences of opinion over the company's organization of its North American business led Vahland to decide not to take over the new post as had been planned, Skoda said in a statement.

"This decision is expressly not connected to the current events around the diesel topic," the statement said.

The German automaker is facing its biggest crisis in its 78-year history following revelations that the company had manipulated emissions tests by installing faulty software in its diesel-powered cars.

How many were involved?

The scandal has shattered trust in the company and rocked both the global car industry and the German economy.

While VW's stock has so far lost a quarter of its market value, the firm is also facing the prospect of massive fines and compensation claims running into billions of euros.

Meanwhile, German magazine "Der Spiegel" reported on Wednesday that at least 30 VW managers were involved in the scandal.

But Volkswagen has denied the Spiegel report. The company stressed that only a small group of executives had overseen installing software in the group's diesel vehicles aimed at cheating on exhaust emissions tests around the world.

"This number is completely unfounded," a spokesman at VW's headquarters in Wolfsburg, Germany said.

sri/uhe (Reuters, dpa, AFP)