The Anti-Defamation League of B'nai B'rith has asked a federal judge to order Lyndon H. LaRouche Jr. and his two attorneys to pay the league $300,000 for allegedly wasting its time and playing dirty tricks during a recent controversial libel suit in which it was involved.

In a motion filed in U.S. District Court in Alexandria this week, the league charged that the perennial right-wing presidential candidate and his attorneys were "playing fast and loose" during the libel trial against NBC. The ADL was a codefendant in the case.

Meanwhile, attorneys for LaRouche have filed a motion in the same court asking the judge to set aside a verdict that orders LaRouche to pay NBC just over $3 million for interfering with the network's business.

The case centered on two NBC broadcasts aired this year in which LaRouche was cast as the anti-Semitic leader of a "political cult." A federal jury in Alexandria rejected this month LaRouche's $150 million libel suit that claimed NBC was part of a conspiracy to destroy his reputation and defame him.

Instead, the jury ordered LaRouche to pay NBC $3,002,000 on the network's countersuit that LaRouche and his associates tried to sabotage an interview the network had scheduled with Sen. Daniel P. Moynihan (D-N.Y.) to talk about LaRouche. The ADL and the director of its fact-finding division, Irwin Suall, were named as codefendants in the suit, stemming from a statement made by Suall in one of the broadcasts that LaRouche is "a small-time Hitler."

In its recent motion to District Court Judge James C. Cacheris, the ADL alleges that LaRouche, who currently resides on a heavily guarded estate in Leesburg, Va., named the ADL as a codefendant solely as a means of harassment.

LaRouche and his attorneys, Odin P. Anderson of Boston and Michael F. Dennis of Mineola, N.Y., failed to produce witnesses and relevant documents and produced little evidence in court that ADL had libeled LaRouche, according to the papers. In court records, ADL cites 23 incidents that it says show "egregious conduct which was designed to harass ADL and increase the costs of litigation."

Anderson and Dennis yesterday maintained that the handling of the suit against NBC and ADL was "absolutely proper" and said they will oppose the ADL request.

Specifically, ADL claims Anderson and Dennis acted improperly by repeating to the court claims by LaRouche that he was being threatened in connection with the case and that the jury might be tampered with without having any first-hand knowledge of those claims.

ADL's request relies on a rule in the Federal Rules of Civil Procedure, standards governing the conduct of attorneys and parties involved in litigation, according to ADL's Washington attorney, Rodney F. Page.

LaRouche alleges that the verdict should be overturned or a new trial set because there was not enough evidence presented in court to sustain it. Robert Rossi, an attorney in Anderson's Boston firm, said yesterday there was not enough evidence to prove that someone had actually tried to sabotage the interviews or that NBC had suffered as a result.

The recent court papers also said the NBC award, $3 million in punitive damages and $2,000 in actual damages, was excessive and the "result of passion and prejudice or other improper influence" on the jury.