World heavyweight champion Vitali Klitschko has said he will defend his WBC belt against both British fighters Dereck Chisora and David Haye in 2012 before deciding whether to retire. The 40-year-old Klitschko will fight Chisora on Feb.18 in Munich with a potential bout against former ex-WBA champion Haye pencilled in for June, although the final date and location have yet to be decided. Although Haye retired on his 31st birthday in October, the Brit has said he will come out of retirement to face the elder Klitschko brother, but he has yet to sign a contract.Klitschko turns 41 on July 19 and says he will leave a decision on his retirement until after the bouts and has no desire to become the world’s oldest heavyweight champion. “The fans can decide whether or not I have enough steam left in my fists,” the Ukrainian told German daily Bild.“I will not break the age record of George Foreman, who was still boxing when he was 45.”