AT&T; Studies Plan to Link Cable Firms : Communications: A network of networks would allow customers to talk, exchange messages, play games.

American Telephone & Telegraph Co. has approached several of the nation’s cable operators about the possibility of creating a network of networks that would allow customers across the nation to talk, exchange electronic messages and play games through their cable lines.

A Wall Street Journal report about the firm’s interlinking vision sent AT&T;’s stock up $2 to close at $62.75 on the New York Stock Exchange on Friday, while shares in the largest cable company, Tele-Communications Inc., soared $1.25 to $25.75 on NASDAQ, an all-time high.

But AT&T; officials sought to downplay the report, stressing that the idea of dozens of smaller networks strung together by AT&T; fiber is “only a concept” and will not become a reality anytime soon.

Still, analysts said the notion of communication between cable systems is a logical next step, and AT&T; is well-positioned to take it. The phone giant, which has moved to stake out a claim in nearly every growth segment of the multimedia and telecommunications market, is one of only a handful of carriers with a sufficiently far-reaching and capacious network to permit the two-way transmission of video and data as well as conversations. Rivals could include MCI and GTE or satellite.

“As a consumer with cable, you interact with a database,” said Bill Weiss, communications director for AT&T;’s consumer services. “What AT&T; is trying to do is make real human interactivity happen through the network.”

AT&T; is trying to persuade the two cable operators in whose interactive television tests it is participating to allow their programs to be a model for the nationwide hookup. It wants a sophisticated video server at the firm’s Bell Laboratories in Murray Hill, N.J., to link Time Warner Inc.’s test system in Orlando, Fla., with Viacom Inc.’s trial in Castro Valley, Calif., scheduled to start this fall. But Weiss said no agreement has been reached.

Customers in both places could then presumably communicate through their televisions.

A Time Warner Cable spokesman would not say whether the company is considering a linkage between its Orlando test--to begin early next year--and that of its competitor in Castro Valley. Viacom officials could not be reached for comment. But TCI Senior Vice President Bob Thomson had a cautiously favorable response.

“We’ve always thought that there would be a network of networks, and there’s no question that AT&T; would have a prominent role in making it function,” Thomson said. “There may be more than one. But the fact that AT&T; has expressed a general willingness to be supportive in our common goal of building a national ‘infostructure’ has been received positively by us and probably by other cable operators as well.”

A physical link between cable systems would not ensure easy communication. The computer, cable and telecommunications industries are hashing out standards for a common interface and language to make all this possible.

But given the conflicting interests and billions of dollars at stake, it has proved no easy task. Likewise, AT&T; says the implementation of its networking ideas may be a long way off.

“This is not a project we have on the boards,” Weiss said. “There’s nothing imminent in this tomorrow or next year or even the next few years.”