Volkswagen CEO Martin Winterkorn reportedly plans to retire in the next three to four years.

Although VW’s advisory board wants to extend his contract by another five years in 2011, in order to find a suitable replacement, Winterkorn would like to retire ahead of that before reaching the age of 67, sources close to the CEO told Financial Times Deutschland.

The paper said the favoured replacement is ex-Continental CEO Karl-Thomas Neumann who is now to head of VW’s most important unit, VW China. His predecessor as Chinese head, Winfried Vahland, meanwhile, will become CEO of Czech unit Skoda. Audi CEO Rupert Stadler became a VW management board member in early 2010 and VW production chief Matthias Mueller is now Porsche CEO.