NEW YORK (AP) CBS and Viacom said Tuesday they will reunite, bringing together their networks and the Paramount movie studio as traditional media giants challenge streaming companies like Netflix .

Viacom CEO Bob Bakish, who will become CEO of the combined company, said the new ViacomCBS will be one of only a few companies with the breadth and depth of content and reach to shape the future of our industry.

Analysts say the reunion will help both companies navigate an ever-competitive streaming landscape.

Viacom owns Paramount Pictures and pay TV channels such as Comedy Central, MTV and BET, while CBS has a broadcast network, television stations, Showtime and a stake in The CW over-the-air network. MoffettNathanson analyst Michael Nathanson said Paramounts movie library could be added to Showtimes premium networks and streaming service, for instance, while CBS streaming service could get a boost from Viacoms Nickelodeon video.

The deal is an all-stock transaction. CBS shareholders will own about 61 percent of the combined company and Viacom shareholders will own 39 percent. The companies say the combined company will have $28 billion in revenue. The reunion, expected to be completed by the end of the year, will be beneficial to earnings and lead to $500 million in cost savings, the companies say.

Acting CBS CEO Joe Ianniello will become chairman and CEO of the CBS division in the combined company.

CBS was one of the first media companies to launch its own streaming service, CBS All Access. The $6-a-month service now has a new Star Trek series, a revival of The Twilight Zone and archives of old and current broadcast shows. CBS says All Access and its Showtime streaming services have 8 million subscribers combined. Thats far less than the 60 million U.S. subscribers that Netflix has, though its comparable with the estimated number of subscribers to HBO Now, that networks stand-alone streaming service.

Now, Disney, Comcasts NBCUniversal and AT&Ts WarnerMedia are jumping in with their own services as well to challenge Netflix, Amazon , Google and other tech companies encroaching into entertainment. To expand its library, Disney bought Foxs entertainment businesses for $71 billion in March, while DirecTV owner AT&T bought Time Warner last year for $81 billion.

Moodys media analyst Neil Begley said the CBS-Viacom reunion would help cut costs and provide greater scale for creating and distributing content.

Theres growing pressure on companies to bulk up content libraries and merging is the easiest and safest way to do that, Begley said.

The combined company would still be small compared with behemoths like Disney, with a vast library of movies and shows, and Netflix, the pioneer in streaming technology. CBS has a market value of $18 billion and Viacom has a market value of about $11.7 billion. Disneys is nearly $245 billion and Netflix is at $136 billion.

Begley said the combined entity might have to consider other acquisitions to keep up with competitors. However, the number of possible targets is dwindling, he said, with whats left mostly smaller companies such as the Discovery and the AMC television networks and the MGM and Lionsgate movie studios.

CBS and Viacom have had an on-again, off-again relationship.

CBS split from Viacom in 2006, but both remained controlled by National Amusements. Shari Redstone, daughter of media mogul Sumner Redstone, runs the holding company.

The split was a way to separate Viacoms networks like MTV, Nickelodeon and BET, which were very successful at the time, from the slower growth of the CBS network.

But over time, the two companies fates were reversed. CBS under longtime chief Les Moonves became more profitable and Viacom struggled, hurt by weakness in its Paramount studio and people dropping cable in favor of streaming.

A recombination makes sense now because media companies are bulking up their content offerings to better compete for ad dollars. But Moonves was against the idea, as CBS was stronger and more profitable than Viacom.

Moonves ouster last year in the face of multiple sexual misconduct allegations changed the dynamic. Under an agreement, Shari Redstone agreed not to push for a reunion for at least two years, but that left open the possibility of CBS itself pushing for it.