Viacom shares just spiked 2.0% after Reuters reported that Sumner Redstone’s National Amusements is about to call for Viacom and CBS to explore a merger.

The exhibition company, which owns 80% of the voting shares at the two media powers, will ask their boards to form independent committees to consider the advantages of a deal.

That call could come this week, the news service says citing “two people familiar with the matter.”

National Amusements has to handle the matter gingerly. Even though it has voting control of Viacom and CBS, each company’s directors also must protect the rights of independent shareholders.

That is a particular concern for CBS, which has been doing well. Some analysts worry that Viacom’s weakening cable network ratings reflect a shift by young viewers to digital platforms, and can not be fixed by the kind of program picking skills that CBS chief Les Moonves might bring.

CBS says in a statement that it “will always act in the best interest of all of its shareholders.”

Moonves told an investor gathering this month that he’s “very happy with the position we are playing now — we think we have a great future as the CBS Corporation now.” He added that the company is “never going to do anything that would harm the CBS shareholders.”

CBS shares are up less than 1% in mid-day trading.

Viacom desperately needs new leadership and a strategic vision. Interim CEO Tom Dooley — who recently replaced Philippe Dauman — plans to leave on November 15. Directors announced last week that they had scrapped the idea of selling a 49% stake in Paramount “in order to consider all options available to the Company.”

Redstone and his daughter, Shari, secured their control over Viacom in August. They reached a settlement agreement with Dauman ending his suits seeking to overturn Redstone’s moves to oust the CEO from the family trust and National Amusements board.

This week Barclays’ Kannan Venkateshwar said that he could envision deal terms that might satisfy Viacom and CBS shareholders. But “the key” is Moonves’ “motivation to take on the complexity of turnaround project when he could just execute on a defined plan for the simpler CBS story.”

But Redstone might make Moonves an offer that’s too sweet for him and his shareholders to refuse. Brean Capital’s Alan Gould said last week that “if the controlling shareholder of both companies wants the deal and [Viacom] makes an attractive enough offer, then we assume a deal can get done.”

Wells Fargo Securities’ Marci Ryvicker says a merger is “not [an option] that we like at the moment,” but adds that a call for one by National Amusements is “not surprising.”

She says a deal might be done if Viacom, which already shoulders a heavy debt load, borrows even more to pay $100 a share for CBS — a nearly 90% premium to its current trading price. Another possibility is for CBS to buy Viacom “at a discount,” a possibility that probably would anger its investors.

Viacom paid $35.6 billion for CBS in 2000, but decided in 2005 to spin it off. At the time it was thought that Viacom would be the fast-growing cable company while CBS would appeal to value investors who wanted predictable, if unexciting, returns.

But thinking about the companies changed as cable matured, and CBS opened a new revenue stream by negotiating retransmission consent payments from pay TV distributors.