Opel CEO Karl Friedrich Stracke stepped down from his post Thursday, the German unit of General Motors said.
Stracke, 56, will be replaced on an interim basis by GM Vice Chairman Steve Girsky. Girsky has in recent months headed the Opel supervisory board.
GM said Stracke will take on special assignments for the US carmaker and report directly to GM CEO Dan Akerson. The company will appoint an interim chairman of Opel soon.
The departure of Stracke comes as Opel, which has been losing money, is about to embark on another restructuring. Parent GM has made clear that, while other divisions of the group are performing well, it also wants Opel to be profitable.
German press reports say the latest Opel reorganization will involve the closing of one or more plants in Europe.