investor MarioGabelli said CEO Philippe Dauman "has to leave" and that hisexit is "amatter of when, not if," Reuters reported July 7.

Gabelli, Viacom's second-largest voting shareholder,reportedly said he did not understand why the board and Dauman would their ouster, since ShariRedstone, who is the presidentof National Amusements and vice chairman of Viacom, "has 80% of thevote."

Dauman andViacom director George Abrams are challenging their from the Redstone family trustand the board of National Amusements, claiming that Shari Redstone is undulyinfluencing her father Sumner Redstone's business decisions. NationalAmusements also attemptedto oust five members of Viacom's board, including Dauman and Abrams, and thedirectors then filed a lawsuitto invalidate their ouster.

Accordingto the report, Gabelli did not state what changes he would like to see atViacom.