Regis Philbin said Monday that he will be leaving Live with Regis and Kelly in order to undergo hip-replacement surgery in New York on December 1. "It really is painful," he remarked on Monday's show, which originated from Las Vegas. A spokesperson for the show said that Philbin would likely return in four to six weeks. The announcement came as reports were circulating on the Internet that the 78-year-old personality is planning to step down as host of the syndicated morning show at the end of his contract in 2011. The tabloid The National Enquirer said last week that Philbin will be replaced by CNN's Anderson Cooper. Such speculation has been circulating since September. Today's (Tuesday) New York Post reported that Cooper will be one of the celebrities replacing Philbin during his absence. Others include Howie Mandel, Michael Bublé, and Christian Slater.