NEW YORK (CNN/Money) - With chairman Sumner Redstone as its champion, a proposal to split Viacom in two seemed like a done deal.

Now, according to one media analyst, Viacom honchos may be rethinking their divorce.

"(T)here's a growing sense in financial circles that the company will stay together," wrote Jack Myers, an analyst who publishes Jack Myers Report, a daily industry newsletter.

Myers' warning Thursday comes after a series of news articles and public statements by Redstone signaling that the breakup plan is moving forward.

At Viacom's annual shareholder meeting last week, Redstone told investors that a final decision on the proposal to create separate, publicly-traded companies would come by the end of June.

Myers, however, noted that the initial enthusiasm toward a Viacom (Research) split has since cooled. Viacom shares rallied on the March 16 announcement -- which also fueled speculation that other media giants, including CNN/Money parent Time Warner, would consider similar divestitures. Today Viacom stock is trading near pre-announcement levels and 13 percent off January's 52-week high.

Myers said there's growing concern that a breakup could put the companies into play -- and potentially into "unfriendly hands."

A Viacom spokesman Thursday called the Myers report "ludicrous," noting that a takeover or merger involving either company would be "more than unlikely" given Redstone owns 78 percent of Viacom stock.

Redstone has said he's "committed" to the plan, which came about after years of acquisitions failed to boost Viacom's stock price.

Redstone is looking to excite investors by creating two companies, one slow-growth and the other fast-growth.

The more staid company would consist of Viacom's CBS and UPN broadcast networks, its Infinity Broadcasting radio and outdoor advertising business, and its book publishing division. The strong cash flow generated by these properties would be used to pay higher dividends and buy back shares. Current Viacom co-president Leslie Moonves would lead the company.

The other company would comprise Viacom's high-growth businesses, including MTV Networks and the Paramount Pictures movie studio. Viacom co-president Tom Freston would head up the second operation.

Redstone has said any breakup would happen in early 2006.

Now, according to Myers, there's concern that such a move would expose both companies to a buyout within 12 to 18 months after the split.

Myers cited Verizon Communications (Research), Vodafone Group (Research) and Comcast Corporation (Research) as potential MTV suitors. SBC Communications (Research), Kirk Kerkorian or Kohlberg Kravis Roberts & Co., he said, could make a grab for CBS.

Calling these takeover scenarios "likely," Myers said they're causing Viacom executives to think twice.

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