Casey Stoner announces retirement from MotoGP at the end of 2012

The news comes after the the Australian, a two-time MotoGP champion, had denied speculation about his exit from the sport in the previous race.

He confirmed at Le Mans on Thursday however, that this will be his last season in MotoGP.

"After a long time thinking, a lot of time talking with my family and my wife, this has been coming for a couple of years now but at the end of this 2012 season I will be not racing in the 2013 championship," said Stoner.

"I will be finishing my career at the end of this season in MotoGP, and go forward in different things in my life.

"After so many years of doing this sport which I love, and which myself and my family made so many sacrifices for, after so many years of trying to get to where we have gotten to at this point, this sport has changed a lot and it has changed to the point where I am not enjoying it. I don't have the passion for it and so at this time it's better if I retire now.

"There are a lot of things that have disappointed me, and also a lot of things I have loved about this sport, but unfortunately the balance has gone in the wrong direction. And so, basically, we won't be continuing any more.

"It would be nice if I could say I would stay one more year, but then where does it stop? So we decided to finish everything as we are now."

In the previous race, the Australian had said speculation about his exit was unfounded.

"Everyone seems quite good at stories and making them up," said Stoner at Estoril earlier this month. "I've said many times in the past that my career's not going to go on much longer, I'm not going to keep going and riding until I'm in my 30s and things like this.

"For me at the moment, I haven't decided what I'm going to be doing, and certainly no one else is going to know what I'm doing."

The 26-year-old from New South Wales had made his MotoGP debut in 2006, after finishing runner-up in the 250cc championship the previous year.

He moved to Ducati in 2007, taking the title with 10 wins, before switching to Honda at the start of the 2011 season. Stoner won his second championship last year, also with 10 victories.

Stoner has scored a total of 35 wins in the top category.

He is currently leading the championship after having won two of the first three races.