Volkswagen CEO Herbert Diess, whose image has been tarnished by the emissions fraud scandal, is leaving his post, the AP reported.

The Wolfsburg-based company unexpectedly announced Friday that Diess would leave his post on September 1 by mutual agreement with the board of directors. No reason was given for his departure. Oliver Blume, CEO of the VW Porsche brand, will succeed Diess.

Diess, who took over as CEO in 2018, led the company during a period of significant change in the industry, including a move to increase production of electric cars. His contract was set to expire in 2025.

Chairman Hans Dieter Pötsch thanked Diess in a statement and praised his role in driving the transformation of the company.

Diess has focused on Volkswagen's transition to zero-emissions cars, but analysts say he has failed to make changes within the company and that the automaker has lagged behind in some key developments, such as software implementation.