It follows the announcement of cost-cutting measures by the sport's world ruling body, the FIA.
Citroen - heading for a third straight constructors title this year - and Peugeot, will not compete in the 2006 championship for financial reasons.
Both teams were awaiting measures to be taken by the FIA to cut costs before announcing a return to competition.
Citroen, who are owned by the same company as Peugeot, PSA, will return to racing without Peugeot in 2007.






