Mikko Hirvonen will join long-time championship rival Sebastian Loeb at the Citroen team next year, it was confirmed on Wednesday.
The 31-year-old Finn had been competing with Ford in the World Rally Championship since the 2003 season, having scored 14 wins in total.
Hirvonen has finished runner-up to Loeb in the championship three times over the past four years.
The Finn will replace Sebastien Ogier at Citroen, the Frenchman expected to be confirmed at Ford.
"Initially contracted until December 2013, Citroen Racing has finally decided to finish their collaboration with Sebastien Ogier and Julien Ingrassia at the end of the 2011 season," Citroen said in a statement.
The French car maker said Hirvonen has signed a two-year deal until the end of 2013.
"Seeing Sebastien Ogier and Julien Ingrassia leave strikes a particular emotional chord in the whole team," said Citroen team principal Olivier Quesnel.
"Citroen Racing trained them, first of all in the JWRC and then in the Citroen Junior Team and the Citroen Total World Rally Team.
"They had a very good season with five victories and third place in the Drivers' World Championship, and they made a productive contribution to the conquest of the manufacturers' title alongside Sebastien Loeb and Daniel Elena who have claimed their eighth consecutive world crown, a unique achievement in motorsport.
"Now, we're very happy to welcome Mikko Hirvonen and Jarmo Lehtinen. They've been our toughest rivals over the last four seasons and we're really looking forward to our future collaboration. Mikko is a talented driver and his consistency will be a big help in our fight to retain the manufacturers' title."