Troubled car maker Volkswagen announces Porsche brand chief Matthias Mueller as new chief executive officer as the German car maker reels from the biggest crisis in its history.

The supervisory board, which met for seven hours on Friday, named four-decade company veteran Mueller to replace Martin Winterkorn, who resigned on Wednesday and took responsibility for the fraud but said he was not personally involved. Mueller will lead Porsche as well until a successor is found.

Mueller is the first non-engineer to run VW

Mueller, who studied information technology and joined the Audi division as a toolmaking apprentice in the early 1970s, is the first non-engineer to run VW since 1992, when Carl Hahn retired from the post.

Since Mr. Müller, 62, moved into the top job at Porsche in 2010, after its takeover by Volkswagen, he has won praise for increasing sales and profits at the sports car maker while preserving its cachet among aficionados.

“My most urgent task is to win back trust for the Volkswagen Group – by leaving no stone unturned and with maximum transparency, as well as drawing the right conclusions from the current situation. Under my leadership, Volkswagen will do everything it can to develop and implement the most stringent compliance and governance standards in our industry,” Mueller said in a statement.

Volkswagen Emissions Scandal:

But VW has admitted that about 11 million cars worldwide are fitted with the so-called “defeat device” – 2.8 million cars in Germany – and further costly recalls and refits are possible. VW shares closed down 4.85 euros on Friday, bringing their loss for the week to 34 per cent.

The US Department of Justice (DoJ) told that it will join the US Environmental Protection Agency’s (EPA) investigation into Volkswagen. “We take these allegations, and their potential implications for public health and air pollution in the United States, very seriously,” the DoJ added.