Two U.S. Supreme Court justices yesterday denied appeals that would have blacked out a scheduled segment of last night's edition of "60 Minutes," the high-rated CBS News program, in the city of Dallas. The rulings ended 48 hours of frantic legal maneuvering that began Friday when a U.S. District judge in New Orleans issued a restraining order that would have made the blackout nationwide.

Justice Byron R. White and Chief Justice Warren Burger both denied appeals that a segment of "60 Minutes" concerning charges of civil rights violations filed against seven New Orleans policemen be blacked out in Dallas on the grounds that the report would prejudice anyone who saw it. The officers are scheduled to go on trial there next month, and jury selection is about to begin.

The show was broadcast in Dallas as scheduled, following a National Football League play-off game.

After a day of hectic scrambling to revise the program if the courts ruled against CBS News, Don Hewitt, executive producer of "60 Minutes," said from his office in New York, "I sometimes think it presumptuous of news people to label Supreme Court decisions as being 'for' or 'against' journalists, but I think there's little doubt that what justices White and Burger did today was a plus for everybody's rights."

The backstage drama began on Friday, when U.S. District Judge Adrian Duplantier, after requesting and being denied an advance transcript of the "60 Minutes" segment, issued a restraining order prohibiting nationwide broadcast of it.

CBS spokesmen had maintained that the original order issued by Duplantier was "clearly unconstitutional" and amounted to prior restraint. Lawyers for CBS News said the blackout order would have meant an infringement of freedom of the press "unprecedented in the history of our nation." On Saturday the Fifth U.S. Circuit Court of Appeals in New Orleans stayed the order.

Then on Saturday night, Duplantier issued another order restricting the blackout to Dallas, the site chosen for the trial because of the intense publicity the case had received in New Orleans. The appeals court stayed that order as well, and attorneys for the seven policemen appeared at the Supreme Court early yesterday morning asking White to nullify the appeals court decision and reinstate the Dallas blackout.

Shortly after noon, White denied the request. "I am not myself convinced that the Court of Appeals was in error in issuing the stay," White wrote in his statement. "And I do not think that if the application were before the full court, five justices would vote to vacate the stay. Accordingly, I deny the application to vacate the stay."

Lawyers for the policemen re-applied at the Supreme Court and their request was again denied, this time by Burger and without comment, at 2:05 p.m.

"60 Minutes," frequently the top-rated show in the nation, has been in and out of court over the years, but Hewitt said yesterday afternoon he could recall no case of similar magnitude in the program's 14-year history. As he spoke, he and members of the "60 Minutes" staff were preparing an alternate segment that Hewitt would not identify--one which had been scheduled for a future broadcast--to fill in the space left by the New Orleans report if it had to be pulled from the show.

There was also the possibility, Hewitt said, that if a judge in Dallas ruled against "60 Minutes" even after the Supreme Court decision, the CBS affiliate in Dallas would join "60 Minutes" in progress--18 minutes and 19 seconds after the start of the program--to avoid airing the New Orleans segment, which was scheduled to open the show. Mike Wallace, correspondent for the report, was returning from Geneva and could not be reached, Hewitt said, so fellow correspondent Ed Bradley had been called in to the CBS News studios to tape a new conclusion for the report, detailing the brief but frenzied legal tussle that almost prevented it from being seen.

Lawyers for the seven New Orleans policemen reportedly emphasized to the courts not only the extreme popularity of "60 Minutes" in Dallas and elsewhere, but the fact that it would be immediately preceded on the air by the Dallas-Green Bay football game, certain to draw a huge local audience. It is estimated that 50 million viewers nationally see "60 Minutes" each week; it always places among the top 10 shows in weekly national ratings compiled by the A.C. Nielsen Co.

In last week's ratings, "60 Minutes" was again No. 1, with a 32.6 rating and a 46 percent share of viewers watching television at the time it was on.

The controversial segment deals with charges of police brutality leveled against the New Orleans Police Department that stem from the November 1980 shooting of a New Orleans police officer, Gregory Neupert, and the subsequent police investigation of that crime. Four black citizens of the city's Algiers district were shot and killed by police in the course of their investigation. Police said all four were killed while shooting or reaching for weapons.

A federal grand jury found no wrongdoing in the shootings, but returned indictments against seven policemen, charging them with violating the civil rights of those questioned in connection with the case. "Among other things, the officers handcuffed or tied persons in their custody to a chair, struck them over the head with a large book, struck them in the chest with their fists, and 'bagged' them--placed a bag over their head and sealed it off at the bottom to cut off the person's air supply," the indictment said.

Lawyers for the policemen argued that broadcast of the segment would make a fair trial impossible. In the appeal brief filed by CBS lawyers after the initial Duplantier decision, CBS contended that "the prior restraint contained in this broad restrictive order is unprecedented in the history of our nation and constitutes a blatant violation of the petitioner's freedom of speech and the press."

In August 1981, Duplantier was interviewed on camera for a two-part "CBS Evening News" report on federal judges who had argued that they should not have to disclose in annual statements how much money they have and what they own, the Associated Press reported.

Asked about his previous contact with CBS News, Duplantier told AP Sunday, "I'm not going to discuss that."

Duplantier and several other judges had argued they should not have to comply with the Ethics in Government Act of 1978. The Supreme Court ruled in January 1981 that all federal judges must comply.

William Leonard, former president of CBS News, said from his Washington home yesterday that while he had no knowledge of the content of the "60 Minutes" report, "the principle at stake is a familiar one, and I gather that common sense seems to have prevailed." Leonard said there had been similar cases during his years at CBS News "but they almost always get reversed before air time. Sometimes it gets a little hairy, though."

Hewitt is known for his zest for controversy, but yesterday, after hearing of Burger's decision, he said, "I'm getting too old for this."