"I regret the resignation of Ferdinand Piech, but it was unavoidable in the end," Stephan Weil said in a statement.

Deputy Chairman Berthold Huber, who is to take over from Piech until a permanent successor has been named, echoed his comments, saying an end had to be put to uncertainty among employees of Volkswagen caused by the leadership crisis that started earlier this month.

(Reporting by Jan Schwartz; Writing by Maria Sheahan; Editing by Georgina Prodhan)