LAS VEGAS — Firing the latest salvo in the great media ownership debate, NBC Universal, News Corp. and Viacom will join the Tribune Co. in asking the Supreme Court to uphold the relaxation of media ownership rules.

But the biggest question remained unanswered Wednesday: Will the Bush administration also petition the court to reinstate the Federal Communications Commission regs, which were tossed out by a U.S. appeals court in Philadelphia?

Appearing at NATPE, Tribune chairman-CEO Dennis FitzSimmons said the chances of the court agreeing to hear the case would be greatly increased with such a nod from the White House and the FCC.

That nod would come from U.S. Solicitor General Paul Clement, who has already been granted two extensions. His final deadline to appeal is Monday.

FitzSimmons and the other members of the panel, who include Washington media watchdog Andrew Schwartzman, said they had no idea which way the administration, including outgoing FCC chair Michael Powell, would go.

Nor did Democratic FCC commissioner Michael Copps, who addressed the NATPE sesh via a satellite video link from Washington, know what Powell’s thinking might be.

If Clement asks for the appeal, it would prove a seminal moment for the White House, which has been largely hands-off on media and entertainment policy. Industry insiders said Powell is surely consulting with Clement in making the decision whether to appeal.

At the center of the legal battle is the FCC’s decision in June 2003 to raise the cap on how many TV stations one company can own and to loosen duopoly rules to allow companies to own multiple media outlets in one market. News Corp. and Viacom are pushing the limits of the current owner cap, while Tribune is pushing the duopoly cap.

Copps and Schwartzman, who are close allies in fighting further expansion by the major media companies, said there’s no better example of the ills of consolidation than the NATPE floor. All but gone are the independent TV studios; instead, the floor is dominated by the major studios, all owned by the entertainment congloms.

Copps urged the FCC to abandon any Supreme Court effort and focus on rewriting the rules, as ordered by the Philadelphia court. He said the high court probably wouldn’t even hear the case until late this year or early 2006, with a final ruling months away from that.

“Now is not the time for more litigation and more delay,” Copps said. “If we don’t do this now, we will go past the point of no return.”

But Bear, Stearns & Co. broadcasting analyst Victor Miller disagreed that the FCC could act any faster than the Supreme Court. He believes the market knows best, and that deregulation promotes competition, which in turn creates more diversity.

Copps, who will begin another round of public field hearings on media ownership in the coming months, called on the Hollywood creative community to hold a forum on independent programming and how to promote diversity in a consolidated market.

The panel’s participants did not want to predict who would replace Powell, although all agreed FCC Republican commissioner Kevin Martin is the top candidate.