Bob Pisano will resign his post as Screen Actors Guild CEO and will be replaced by Greg Hessinger, national executive director of the American Federation of Television & Radio Artists, sources said Tuesday.

An SAG spokesperson said the guild will not confirm or deny the shakeup until after a board of directors meeting this Sunday. The board reportedly must vote on Mr. Hessinger's appointment.

"SAG has scheduled a meeting of its board this week to discuss issues related to its executive leadership," the spokesperson said. "But we will not comment on any future changes until the board has a chance to discuss and vote on those issues."

Mr. Pisano also serves as national executive director of SAG.