Viacom Sumner Redstone

Redstone, as executive chairman of both Viacom and CBS, had controlled the two companies through privately held National Amusements

Redstone, as executive chairman of both Viacom Inc and CBS Corp , had controlled the two companies through privately held National Amusements

A big step toward a potential management shake-up of the almost $20 billion company

Reuters reported Tuesday that Redstone, who turns 93 next week, had the power to remove certain members of the trust, including Dauman