Casey Stoner to Retire from Motorcycle Racing

Two-time world MotoGP champion Casey Stoner has announced he will quit motorcycle racing at the end of the season for "family reasons."

Stoner, who has won 35 MotoGPs in his career and leads the current standings after winning two of the season's three events, made the announcement at a news conference ahead of Sunday's French Grand Prix.

The 26-year-old Australian won world titles in 2007 and 2011.

He became a father for the first time in February when his wife Adrianna gave birth to a daughter.

Stoner said "after a long period of thought and numerous discussions with my wife and family, I have decided to stop competing at the end of the season."