"I am doing this in the interests of the company even though I am not aware of any wrongdoing on my part," Winterkorn said after an emergency meeting with Volkswagen directors.

Winterkorn, 68, was Volkswagen (VLKAY) CEO for eight years. The German company, which also owns the Audi and Porsche brands, had just achieved his long-standing goal of overtaking Toyota (TM) to become the biggest automaker three years ahead of target.

But his position had looked increasingly precarious since the scandal broke Friday, when U.S. regulators said the company had deliberately programmed some 500,000 diesel-powered vehicles to emit lower levels of harmful gases in official tests than on the roads.

The crisis escalated Tuesday when Volkswagen revealed it had found significant emissions discrepancies in 11 million diesel vehicles worldwide.

Winterkorn, an engineer and former head of Audi, said he was stunned by the scale of the misconduct, and was accepting responsibility to clear the way for a "fresh start" for the company.