Four-time World Touring Car champion Yvan Muller has announced he will retire from the series at the end of the season to bring an end to the most successful career in the championship's history.

The 47-year-old has made the official announcement on the eve of the WTCC Race of China marking the end of the 11-year career stint in the series having claimed four titles (2008, 2010, 2011 and 2013), 29 pole positions, 48 race wins, 125 podium finishes and 38 fastest laps.

Muller confirmed the decision was not solely down to age or Citroen withdrawing its factory effort from WTCC at the end of the season in order to focus in efforts in the WRC, but he has also lost the 'desire and motivation' for a full WTCC campaign.

"I am not sure that age is the main factor when it comes to ending a career. It's more a matter of desire and motivation," Muller said. "With all the testing, the simulator sessions, the physical training and the travel to the race venues, a season of professional motor racing requires a level of personal commitment that I am no longer prepared to put in.

"I am at a time of my life where I want to do something else and I am happy to be able to make that decision after eleven seasons of FIA WTCC. I've had some great experiences over my career.

"These three seasons with Citro?n Racing have been particularly special, even though I never managed to be World Champion driver with this team. But I will always be proud of having helped to build our racing programme and develop the Citro?n C-Elys?e WTCC. I have also met some great people who are passionate about their job and have a fierce competitive spirit."

Muller began his racing career in karting, taking the World Championship runner-up in 1985 and being European Championship winner in 1986 before progressing to become British Formula 2 champion in 1992.

Despite being denied opportunities in F1, Muller switched to touring cars becoming French Supertouring champion in 1995. The French driver then switched to the British Touring Car Championship in 1998 after stints in Germany and Italy and enjoyed a successful eight year highlight by a title in 2003.

After brief dips into ETCC Muller made the full-time switch to the WTCC in 2006 going on to claim titles with SEAT and Chevrolet.

Muller joined the Citroen effort at the start of 2014 but has had to play second-fiddle to Jose Maria Lopez with two consecutive runner-up finishes in the championship.

"The whole Citro?n Racing team is proud to have Yvan Muller in its ranks," Yves Matton, Citroen Racing team principal, said. "Every time we get involved in a competition, we look to recruit the best drivers. That is why we invited Yvan to join us from the start of our involvement in FIA WTCC. We will not forget his contribution.

"Coming in from rally driving, we had everything to learn, and he has always been more than happy to offer the team the benefit of all his experience. He is a great competitor and a great guy, who has always put Citro?n's interests first.

"It is to Yvan's credit that, after three seasons with us, he has decided to end his career at a point when he is still capable of winning pole positions, races and titles. He will always be part of the Citro?n Racing family and we wish him all the best for the next stage of his life, which we will follow with interest."