LONDON — World champion Ronnie O'Sullivan is set to give up his title without a defense after it was announced Tuesday he does not plan to compete in any World Snooker Tour events for the rest of the 2012-13 season. Although the 36-year-old returned to play in a low-profile Players Tour Championship event in September, he withdrew from last week's International Championship in Chengdu, China, citing illness. World Snooker chairman Barry Hearn, quoted by the BBC, said: “I have spoken to Ronnie and he has decided to withdraw from any events he has entered. He will not play this season.” — Reuters