Michael Sohn, AP
Newly appointed Volkswagen CEO Matthias Mueller during a press statement after a meeting of Volkswagen's supervisory board in Wolfsburg, Germany, Friday, Sept. 25, 2015, after CEO Martin Winterkorn resigned on Wednesday amid an emissions scandal. (AP Photo/Michael Sohn)

BERLIN — Volkswagen's board has named Matthias Mueller, the head of the group's Porsche unit, to be the new CEO and to lead the world's top-selling automaker past a growing emissions-rigging scandal.

Friday's appointment by the supervisory board meeting comes after the previous CEO, Martin Winterkorn, quit the job this week over the scandal, which has damaged the company's reputation and threatens its business.

Volkswagen has admitted to cheating on diesel car emissions test in the U.S. by using a software on 482,000 cars. It has said some 11 million cars worldwide have the software. The company now faces a mountain of difficulties, from class action lawsuits to fixing the software itself.

Mueller, 62, on Friday pledged to do everything to win back the trust of the public.

"We stand by our responsibility," said, adding, however, that "carefulness is even more important than speed."

Mueller said the company would introduce "even tougher compliance rules" and pledged to make VW "an even stronger company."

Winterkorn, who had been CEO since 2007, said he took responsibility for the "irregularities" found by U.S. inspectors in VW's diesel engines, but insisted he had personally done nothing wrong.

Pylas contributed from London.