A U.S. District Court judge denied a motion by the Anti-Defamation League of B'nai B'rith yesterday that Lyndon H. LaRouche and his two attorneys pay damages of $300,000 to the league for harassment during a recent libel trial.

The ADL alleged in its motion that LaRouche had named the league as a codefendant in his libel suit against NBC for no other reason than to harass its members.

LaRouche, 62, a right-wing political leader who lives on a guarded estate in Leesburg, was listed last month on the presidential ballot in 18 states and the District.

In his $150 million libel suit, LaRouche accused NBC, with the help of the ADL, of conspiring to defame him in two broadcasts. The jury rejected that charge on Nov. 1 and instead awarded $3.002 million to the television network. NBC, in its successful countersuit, charged LaRouche and his associates with sabotaging an interview about LaRouche with Sen. Daniel P. Moynihan (D-N.Y.).

The ADL's Washington attorney, Rodney F. Page, argued yesterday that LaRouche did not have adequate evidence that the ADL had libeled him when the claim was filed on Feb. 24, violating a federal court procedural rule.

However, U.S. District Court Judge James C. Cacheris said that even though LaRouche filed the libel suit prior to the "First Camera" broadcast on March 4, in which an ADL official called LaRouche a "small-time Hitler," he had sufficient evidence to name the organization in the lawsuit.

Page also argued that NBC conducted 108 interviews, most of them critical of LaRouche, and yet LaRouche and his attorneys chose to single out the ADL. "From day one they were anti-ADL," Page said. "Their only intention was harassment."

Cacheris said he will rule in January or February on LaRouche's new request that the $3.002 million verdict be overturned or a new trial set. But yesterday the judge indicated that he was pleased with the findings of what he called an "intelligent jury."