Comedian Chris Rock has officially ruled himself out of the running as host for next year's Academy Awards. Rock took on Oscar-hosting duties for the first time in February, and while he drew younger viewers his jokes skewering stars like Jude Law, Tobey Maguire and others alienated some members of the Academy of Motion Picture Arts and Sciences. His comments prompted Sean Penn, when he took the stage later, to defend Law as "one of our finest actors". And following months of speculation over whether Rock will return for the March 5 ceremony, his publicist Matt Labov says, "He is not hosting the Academy Awards." Labov adds that Rock doesn't want to do the show "in perpetuity" but would "like to do it again down the road." A spokesman for the Academy has declined to comment about the hosting duties, although an announcement on the selection is expected in the next few weeks.