LAS VEGAS, United States (AFP) - Vitali Klitschko will have right knee surgery this week and have 90 days to reschedule his heavyweight title defence against Hasim Rahman, frustrating the challenger as well as promoter Don King.

The Baltimore Sun reported Monday that Klitschko will undergo surgery to repair a torn meniscus and that the World Boxing Council agreed to a plea that allows him to remain champion despite a fourth postponement of the Rahman bout.

The WBC told Klitschko he must fight Rahman, who captured an interim crown in August by beating fellow American Monte Barrett, or lose the title. A new date for the fight is expected this week.