Viacom's president and chief operating officer Mel Karmazin has resigned, it was confirmed today.

"After more than 20 years with the Company, for personal and professional reasons, I have decided to leave Viacom and pursue other challenges," explained Karmazin. "Viacom is performing exceptionally well with leadership positions in all of its businesses. The Company’s very talented management team will ensure its continued success.???

A corporate succession plan was immediately announced by the company, which is installing MTV Networks chief Tom Freston and CBS Entertainment president Leslive Moonves as co-presidents and co-Chief Operating Officers.

Current chairman and CEO Sumner Redstone will be leaving the post of CEO at Viacom some time in the next three years, and commented today that "Tom and Les are the two leading candidates to be the next CEO of Viacom."