U.S. District Court Judge David Edelstein today denied a request by the International Business Machines Corp. that he disqualify himself from presiding over the massive Justice Department anti-trust case against the computer gaint.

On July 19, IBM stunned participants in the decade-long case by accusing the 70 year old judge of showing "bias and prejudice" throughout the case, which has been at the trial stage since May 1975.

But today, in his 33 page decision on IBM's motion, Edelstein said the company's allegations -- which were supported with 2,000 pages of documentation -- "demonstrate no personal extra-judicial bias or prejudice on the part of this court."

Edelstein borrowed fellow U.S. District Court Judge John Sirica's words from his denial of a similar motion against him in the U.S. vs Mitchell case, when he said: "Defendants' best effort consists of alleging a battery of facts from which it is hoped one would infer some bias favorable to the prosecution. Even then, defendants have cited nothing to suggest that any such bias, which the court assures them does not exist, is personal."

IBM had charged that Edelstein, who is hearing the trial without a jury, has demonstrated "a personal bias and prejudice against defendant (IBM) and in favor of plaintiff (U.S)" during his seven years as presiding judge over the case.

Addressing the question of why it had waited seven years to accuse the judge of prejudice -- an unprecedented amount of time -- IBM stated in an affidavit that "what in the past we saw as extremely vexatious and wrong-headed actions by Chief Justice Edelstein may now, we believe, be seen as strong indications of bias and prejudice."

The IBM motion for disqualification was supported by an affidavit signed by five prestigious IBM directors who are lawyers, former Transportation secretary William Coleman Jr., former Housing and Urban Development secretary Carla Hills, former Pennsylvania governor, congressman and U.S. ambassador to the United Nations William Scranton, Du pont co. chair- man Irving Shapiro (a former Justice Department antitrust attorney along with Edelstein) and former U.S. ambassador to France John Irwin II.

But Edelstein was not swayed by IBM's arguments, which cited the fact that a disproportionate number of his courtroom decisions went against the company and for the government, and that he constantly had berated IBM's attorneys and witnesses in court.

"What IBM fails to note is that IBM itself was responsible for raising the overwhelming majority of objections at trial," Edelstein said in his ruling. "The fact that IBM lost a majority of its objections and motions indicates not bias of the judge but rather lack of merit to the objections and motions."

"More important, IBM's claim of bias upon the court's adverse ruling is legally insufficient," he added.

As for the charge that he was hostile to IBM attorneys and witnesses, Edelstein said, "Even if IBM's allegations with respect ot the court's treatment of witnesses were true, the court finds them legally insufficient to support a claim of bias.

"IBM has made no showing that the court's treatment of witnesses stems from an extrajudicial source rather than from its duty to protect the record from distortion and obfuscation," he said.

The IBM case is one of the most controversial in the Justice Department's history of antitrust enforcement. During the decade since the company was charged with unfair practices in the computer business, that industry has changed dramatically, with hundreds of new firms entering the market.

There have been indications from government attorneys and from high Justice Department officials that the case should be settled. It already has filled 90,000 pages of transcript and spanned 612 days in court.

IBM today declined to comment on the latest ruling. But legal experts say it is likely the company will appeal the action to the U.S. Court of Appeals, an action likely to tie up the case even longer. It already has been suspended for several weeks while Edelstein considered the removal motion.