CBS
Corp.
and
Viacom
Inc.
said Thursday that their boards have formed special committees to evaluate a potential merger, a deal that would reunite the two big pieces of the Redstone familyâs media empire.
Shari Redstone, vice chairman of both companies, is pushing for a merger, people close to the discussions say. She, along with her 94 year-old father, Sumner Redstone, controls CBS and Viacom, with a roughly 80% controlling stake in each company through their holding company National Amusements Inc.
This is the second time in less than two years that Ms. Redstone has tried to get CBS and Viacom back together, after they split up in 2006.
Ms. Redstone believes both companies need greater scale to better compete against bigger rivals, people familiar with her thinking say. The new push comes as
AT&T
Inc.
tries to acquire
Time Warner
Inc.
and
Walt Disney
Co.
has a pending deal to purchase the majority of
21st Century Fox
âs
entertainment assets.
CBS Chief Executive
Leslie Moonves
has previously resisted attempts to merge with Viacom and people close to him say he is wary of the combination.
In a statement, National Amusements said it supports the moves by CBS and Viacom to explore the deal, âwhich we believe has the potential to drive significant, long-term shareholder value.â
CBS and Viacom said in statements they wouldnât comment further on the matter.
Ms. Redstone took pole position in the family empire in 2016 after a power struggle in which Viacomâs earlier management team was ousted.
Now she faces the challenge of setting up both companies for the future, especially Viacom, owner of more than two dozen cable channels including MTV, Nickelodeon and Comedy Central and the Paramount Pictures studio. Viacom was especially hard hit in recent years as young viewers migrated away from its networks.
Merging with CBS is a tempting solution: It would help shore up Viacomâs balance sheet and combine its channels with a valuable portfolio that includes prime-time CBS programming, sports content such as NFL football and the premium cable channel Showtime.
Ms. Redstone reached out to with Mr. Moonves last month to make the case for restarting merger talks, people familiar with the situation said. Ms. Redstone also began pressing for new blood on CBSâs board, the people said.
CBS isnât opposed to growing, but it isnât yet convinced that Viacomâs assets are the best path to scale, a person familiar with Mr. Moonvesâs thinking said.
Viacom Chief Executive Robert Bakish, meanwhile, has been attempting a turnaround there. When Mr. Bakish was named chief executive just over a year ago, the company was losing revenue, its debt was teetering on junk status, its channels were losing audience and its Paramount studio had just lost nearly half a billion dollars in a single year.
He has tried to right the ship by improving relations with Viacomâs distribution partners, slimming the companyâs strategic focus to six flagship cable channel brands, starting a digital content studio and improving collaboration between divisions.
Under Mr. Bakish, Viacom has maintained its cable channel-carriage agreements but it has been forced in some cases to accept lower fees, hurting the long-term outlook for its distribution revenue.
Analysts think Viacom would have greater leverage to negotiate with distributors if it were part of CBS. MoffettNathanson analyst Michael Nathanson said a deal also could offer âsubstantial cost synergies.â
Others counter that in this case bigger may not be better. âWe do not view âscaleâ as an all-encompassing positiveâespecially when âscaleâ just means slapping two completely different companies together just to get bigger,â said Wells Fargo analyst Marci Ryvicker in a recent note.
Both Viacom and CBS had fallen short of analystsâ initial expectations for profitability in 2017âalthough Viacom fared much worse than CBSâand the pressure to consolidate has only increased, people close to the situation say.
Ms. Redstone believes Mr. Bakish would make sense as Mr. Moonvesâs eventual successor at a merged company, the people familiar with the matter said.
Inside CBS, Chief Operating Officer Joe Ianniello is seen as Mr. Moonvesâs successor and has a clause in his contract allowing him to leave at the end of this year if he isnât named president or if someone else is named president or chief executive, according to a regulatory filing.
Mr. Moonves, who is well-regarded by Wall Street, has a few cards to play against Ms. Redstone if he ultimately isnât convinced that a merger is the right move. According to his contract, he can leave for âgood reasonâ if a non-executive chairman is appointed, or if the board âceases to consist of âoriginal independent directorsâ and âqualified replacement directors.â â
Ms. Ryvicker said in her report that a departure by Mr. Moonves would weigh on CBS shares.
Write to Joe Flint at joe.flint@wsj.com and Keach Hagey at keach.hagey@wsj.com