Shari Redstone got her wish.
After more than a decade apart, CBS and Viacom, both under her control, agreed to merge on Tuesday in a deal that will reunite a roster of once-mighty media businesses. Viacom’s Paramount film studio and MTV and Nickelodeon cable networks will be added to the broadcast giant CBS and the book publisher Simon & Schuster.
The combination of CBS and Viacom is a victory for Ms. Redstone, the leader of a family business that has led the two media giants for two decades. Their reunification (the two companies were once a single entity, called Viacom, until they were split up in 2006) was seen as necessary at a time when television audiences have eroded. Tech platforms like YouTube, Instagram and Netflix have chipped away at big media, eating into the once-fat profits that companies like CBS and Viacom reaped.