What's hot at CBS (CBS)? Despite lukewarm ratings for its network TV shows, the stock could sizzle. According to Street pros, moguls such as Barry Diller and Sumner Redstone are interested in acquiring the CBS TV network and its 18 TV stations--if not the whole company.

The stock, now at 31, has gained only 16% this year. But it has more than doubled since 1996, when it was still called Westinghouse Electric. If buyout speculation spreads, the stock could soar.

The likely outcome, says Mark Boyar, who heads the New York investment firm that bears his name, may be CBS selling or spinning off its TV network and its 18 owned stations, and retaining the radio operations--Infinity Broadcasting, CBS Radio Network, and more than 70 stations. CBS has also bought American Radio Systems, which owns and provides programs for 100 stations. In addition, CBS owns two cable-TV networks: The Nashville Network and Country Music Television.

Mel Karmazin, the new COO at CBS, ''is a dynamic executive and a winner: He gets upset when the stock is down,'' says Boyar. ''So he won't stand in the way of enhancing CBS's value--including the sale or spin-off of assets.'' And Diller, he notes, has always wanted CBS. Six months ago, rumors also swirled about Diller's attraction to CBS.

Tom Graves of Standard & Poor's isn't sure a deal is imminent, but notes that CBS is a ''logical'' candidate for either USA Networks (USAI), which Diller heads, or Viacom (VIA), which Redstone runs. A CBS merger with either company ''could make sense--but more so with Diller's company,'' says Graves. USA Networks operates TV stations devoted mostly to local programming. If Diller owned the CBS network and TV stations, says Graves, Diller would have extensive outlets for his TV shows.

Analyst Edward Hatch of Warburg Dillon Read figures that its TV stations alone are worth $8.4 billion, or 14 a share, and its TV network $3 billion, or 5 a share. The radio assets, he adds, are worth much more--$25 billion, or 25 a share. The cable network is worth another $2.5 billion, or 4 a share.