Sumner Redstone To Step Down As Head Of CBS; Moonves To Assume Role

Stocks in the Media group have gotten some solid post-market action Wednesday afternoon following a big management shake up related to legendary media magnate Sumner Redstone.

CBS Corporation (NYSE: CBS) announced the resignation of the media mogul from the role of Executive Chairman; he has been named Chairman Emeritus, a label meant to designate a long-standing honor.

The company announced current CEO and President Leslie Moonves will replace Redstone in the Chair role.

As the Redstone family has long been a majority holder in both CBS and close peer Viacom, Inc. (NASDAQ: VIA), shortly after the CBS press release was issued, Viacom published a press release announcing the "Board of Directors is scheduled to meet tomorrow."

As both investors and media heads began digesting the news, CNBC's David Faber tweeted "Viacom board to meet tomorrow to elect Redstone's replacement as Chairman-sources. Regardless, he's still the controlling shareholder."

A Reuters report from late Wednesday night suggested the Viacom meeting set for Thursday was likely to discuss and potentially announce Sumner Redstone will also be stepping down from its Board.

CNBC's David Faber Tweeted Thursday morning, "Viacom ceo Philippe Dauman seen likely to add title of Chairman over Shari Redstone's objections. Board meets this morning."

Taking a look around the Media sector, shares of CBS traded up about 4 percent after-hours and Viacom shares last traded at $51.25, up nearly 8 percent.

Other players like Twenty-First Century Fox Inc (NASDAQ: FOXA) and Comcast Corporation (NASDAQ: CMCSA) saw bidder and seller interest, however, were largely unchanged.