A bipartisan group is in talks to allow votes on some nominees and avoid a showdown over the minority party’s filibuster rights.

Efforts to avert a confrontation over federal judicial appointments intensified Thursday, even as Republicans drew closer to forcing a vote on one of President Bush’s controversial nominees.

Senate Majority Leader Bill Frist (R-Tenn.) said he would file a motion today that would start the clock ticking toward ending the debate on Bush’s nomination of Texas Supreme Court Justice Priscilla R. Owen to the U.S. 5th Circuit Court of Appeals in New Orleans.

Barring a last-minute compromise, Frist’s move would lead to what has become known as the “nuclear option” -- a GOP push early next week to change procedures to prevent Democrats from blocking votes over controversial judicial nominees, including those for the Supreme Court.

A group of a dozen or so moderate senators seeking a compromise to derail the showdown held closed-door meetings throughout the day.

Senators exiting the sessions reported making progress, but provided no details.

“We’re as optimistic as we’ve ever been, but we’re not quite there yet,” said Sen. Mark Pryor (D-Ark.).

The group of six Republicans and six Democrats is attempting to undercut the drive by Republicans to eliminate filibusters of judicial nominees by reaching their own deal: Democrats would pledge not to filibuster upcoming nominees except in “extraordinary circumstances.” Republicans would not vote for changes in the filibuster rules, except if, in their view, Democrats at some point violate the spirit of the agreement.

Sen. Ben Nelson (D-Neb.), who has played a major role in seeking a compromise, said that much effort in the last few days had been spent on building trust among the group.

“Every time we’ve gotten together, we’ve increased that trust, that mutual respect and the desire to work together,” Nelson said after one session.

The talks disbanded in the early evening Thursday, with the senators agreeing to resume their deliberations Monday.

“Let’s pray about it,” said Sen. Robert C. Byrd (D-W.Va.), another of the leading negotiators.

The issue at the forefront of current negotiations is a proposal championed by Byrd and Sen. John W. Warner (R-Va.) to create an independent, bipartisan commission -- under the auspices of the Senate Judiciary Committee -- that would pick a nonbinding pool of nominees to propose to the president to fill any Supreme Court vacancies.

By proposing nominees, the commission would signal that the potential picks would have bipartisan support, said Byrd spokesman Tom Gavin.

Owen is one of 10 Bush nominees to the federal appellate courts that Democrats blocked during his first term through threat of the filibuster.

This year, Bush renominated seven of them, including Owen, sparking the dispute over use of the filibuster against them.

It takes 60 votes to end a filibuster; Republicans want to change the rules so that all judicial nominees would have an up-or-down vote and win confirmation if they gained 51 votes, a simple majority, in the 100-member Senate.

On Thursday, Owen spent a second day on Capitol Hill, meeting privately with senators, including at least one of the moderates who is contemplating compromise, Sen. Ken Salazar (D-Colo.).

“He has not made a decision on any of the nominees at this point,” Salazar spokesman Cody Wertz said after the meeting.

Frist convened a second day of floor debate, noting that he expected many more hours of discussion before the conflict reached a climax next week.

“In the days ahead, we will continue that debate -- 10 hours, 20 hours, 30 hours, as many hours as it takes for senators to air their views,” Frist said. “But at some point, that debate should end and there should be a vote.”

As Republicans and Democrats traded lecterns throughout the day, there were signs of growing acrimony.

One of the key disagreements involves which side is breaking precedent in the dispute.

Democrats accuse Republicans of violating Senate rules in their drive to end filibusters of judicial nominations.

Republicans accuse Democrats of violating precedent by using the filibuster to block nominees who are supported by a majority of senators.

In perhaps the day’s most contentious remarks, Sen. Rick Santorum (R-Pa.) invoked the name of German dictator Adolf Hitler in making the Republicans’ case.

“Imagine, the [precedent] has been in place for 214 years that this is the way we confirm judges, broken by the other side two years ago” through threat of filibusters, Santorum said.

He then said that for the Democrats to attack Republicans for trying to break Senate rules is “the equivalent of Adolf Hitler in 1942 saying, ‘I’m in Paris. How dare you invade me? How dare you bomb my city? It’s mine.’ ”

Sen. David Vitter (R-La.), a freshman, took the unusual step of criticizing the senior senator from his state, Democrat Mary L. Landrieu, for joining her party in blocking a vote on Miguel Estrada, a Bush judicial nominee, in 2003.

“Many folks, including me, quite frankly, were disappointed that Sen. Landrieu a few years ago filibustered and supported that filibuster,” Vitter said. “Well, this is an opportunity to set that record aside and do the right thing and give all of these judicial nominees a fair up-or-down vote.

Sen. Mitch McConnell (R-Kan.), the majority whip, accused Democrats of “shutting down the work” of Senate committees by refusing to waive a rule that limited hearings to two hours while the Senate was in session.

That prompted a response from Senate Minority Whip Richard J. Durbin (D-Ill.), who offered a motion to immediately start a debate on four less controversial judicial nominations whom Republicans have set aside to focus on Owen.

“We could have approved four more judges for President Bush ... moved forward on a bipartisan basis and done it before lunch,” Durbin said. One senator referred to the new “Star Wars” movie in his remarks. Sen. Frank R. Lautenberg (D-N.J.) compared the scenario playing out in the Senate to the plot of the new George Lucas “Star Wars” film: “Episode III Revenge of the Sith.”

“In this film, the leader of the Senate breaks the rules to give himself and his supporters more power,” Lautenberg said, unveiling a large poster of the character in the film. “As millions of Americans go to see this film this week and in the weeks ahead, I sincerely hope it doesn’t mirror actions taken in the Senate of the United States.”

Times staff writers Richard Simon and Janet Hook contributed to this report.