WOLFSBURG, Germany: The biggest car maker in Europe, Volkswagen, has announced the unexpected departure of its ceo just six months after the company renewed his contract.

Bernd Pischetsrieder will step down at the end of the year and will be replaced by Martin Winterkorn, the current head of the firm's Audi unit.

VW has given no reason for the move, but chairman Ferdinand Piech, who hired Pischetsrieder in 2000, had raised questions earlier this year about his reappointment because of his clashes with unions over 20,000 job cuts in Germany.

The board, however, unanimously extended Pischetsrieder's contract through until 2012 and his future seemed assured.

VW's French competitor, Peugeot Citroën, meanwhile, has named has named Christian Streiff, former Airbus head, as its next ceo.

He will take over from Jean-Martin Folz, who will quit in January when he turns 60. He has been at the Peugeot helm for ten years.

Streiff lasted just 99 days at Airbus. He resigned after clashes with the board over radical reforms, including big job cuts that he planned to introduce to combat the problems facing the A380 airliner program.

Data sourced from BBC Online and Financial Times Online; additional content by WARC staff