The Bush administration has become entangled in a bitter, decade-long battle between the three television networks and the Hollywood studios that produce most of their shows, signaling to the Federal Communications Commission that it sides with the networks.

Next month, the FCC is scheduled to rule on the fate of federal regulations that now prevent the networks from owning and syndicating the entertainment programs they air -- a regulation that grants the studios and independent producers an effective monopoly over TV reruns worth billions of dollars.

On Friday, the White House made public a letter from Chief of Staff John Sununu opposing extension of the so-called financial syndication rules after the Los Angeles Times reported that the administration was moving toward the studio position. The article said the change reflected Hollywood's "behind-the-scenes political clout," which to many in Washington fingered Jack Valenti, the colorful president of the Motion Picture Association of America.

"They {Hollywood} blew this thing up and forced {Sununu} to say something," said a White House official involved in the issue who asked not to be identified.

Valenti, who has spent 10 years fighting the "fin-syn" battle inch by inch, story by story, was quick to respond yesterday. He denied he had spoken to the Times or attempted to claim victory in the lobbying battle. Instead, he suggested he was the object of a smear campaign.

"Practically all of the network guys I know are first-class professionals. But obviously one person is doing some very professionally organized disinformation on this issue. If you can destroy Jack Valenti by portraying him as a roaring braggart, you destroy the case of the producers."

Valenti, who with a salary of $672,500 is the city's highest paid association executive, took pains to play down his reputation as one of Washington's foremost power brokers.

"I have never laid claim to being a powerful lobbyist," said Valenti. "I am not a powerful lobbyist. I have no special insights or influence at the White House."

The studios have employed former Reagan White House officials Craig Fuller and Kenneth Duberstein to lobby their case.

The White House position has become a critical factor in the fin-syn debate. The term of FCC commissioner James Quello will expire in June, while the four other commissioners -- all Bush appointees -- will face reappointment over the next four years.

This is not the first time the White House has weighed in on the issue. Back in 1983, the FCC voted to repeal the financial syndication rules. But after Ronald Reagan received a complaint from his former agent, Universal Pictures head Lew Wasserman, commission members were called to the White House for a dressing down. They later backed off from the earlier position.

According to one congressional source, Alfred Sikes, the FCC's current chairman, wants to avoid a rerun of the 1983 turnabout by understanding clearly what the administration's position is on the fin-syn rules.

"If {Sununu's} letter wasn't an endorsement of {a change in the rules}, I'm not sure what an endorsement would look like," the White House official said yesterday. "It was intended to be an endorsement."

Currently, the networks are prevented by the rules from sharing in the sale of these programs to independent domestic and foreign stations and cable operators, and have lobbied for repeal or revision of the regulations.

Meanwhile, the studios, which are entitled to resell the programs they produce, are attempting to protect the status quo, arguing that the rules have fostered increased competition, both among broadcasters and within the production community.

The administration first signaled its tilt toward the network position last week in a single paragraph buried in the 411-page Economic Report of the President.

White House economic adviser Michael Boskin wrote that "government restrictions on ownership, carriage, or syndication of programming inhibit competition, reduce efficiency, and are generally an ineffective means of addressing any problems of market power that may exist."

But Hollywood's lobbyists quickly contacted reporters and told them the White House was willing to publicly distance itself from Boskin's written comments. The White House then issued a statement on Wednesday saying it would have no comment on the matter because "the syndication rules are a matter before the FCC."

On Thursday, the Los Angeles Times carried an article portraying the White House's statement as evidence of Hollywood's success in persuading the administration to back away from the Boskin report. That prompted Sununu on Friday to reinforce the administration's support of the Boskin report in a letter sent to Rep. Michael Oxley (R-Ohio), who had requested a clarification.

Although favoring some change in the fin-syn rules, the White House has not blatantly spelled out its position because it may be wary of the broad political consequences of doing so, according to one congressional source.

By coming out too strongly in favor of the network position, the administration could risk losing whatever financial support Hollywood's producers may give to Republican candidates next year when California will be choosing two new senators and more than a dozen new members of the House.

Studio executives and Hollywood figures often lead major political fund-raising efforts, although Hollywood historically has supported Democratic candidates and liberal causes.

JOHN SUNUNU: His letter reaffirmed White House opposition to rules preventing the three television networks from owning and syndicating the entertainment programs they air. "They {Hollywood} blew this thing up and forced {Sununu} to say something, as opposed to letting two obscure sentences go at that," said a senior White House official.

JACK VALENTI: The Motion Picture Association of America president says he was not behind claims by the movie industry of early victory on the syndication rules issue. "Obviously one person is doing some very professionally organized disinformation on this issue," Valenti said. "I have never laid claim to being a powerful lobbyist."

ALFRED SIKES: The Federal Communications Commission chairman, a Bush appointee, has already come out in favor of some modification of the syndication rules. With the FCC set to make a decision within weeks, the administration's stand could influence the debate within the agency. At stake are billions of dollars in revenue from the sale of TV program reruns.