U.S. District Court Judge Gerhard Gesell refused yesterday to delay the FBI's impending release of thousands of additional documents bearing on the assassination of President Kennedy, but agreed that author-critic Harold Weisberg should get a free set "with all reasonable dispatch."

The FBI plans to make public on Wednesday some 40,000 pages of headquarters documents on the 1963 assassination at a cost of 10 cents a page for those who want their own copies. The bureau released an initial 40,000 pages last month on a similar basis.

An outspoken critic of the Warren Commission and author of six books on the JFK murder, Weisberg noted that he has had freedom-of-information requests for such documents pending for years and that he had asked for a waiver of fees in mid-November. He filed for a federal court injunction in late December, arguing that he was entitled to a free set at least by the time the final batch was made public.

Charging that such voluminous FBI releases amounted to "media events" that effectively camouflage unjustifiable deletions and paper over "a very careful job of sifting and concealing," Weisberg said the Justice Department and the FBI had completely ignored his request for a waiver of the fees, which he said he could not afford.

Announcing his decision from the bench after an hour-long hearing, Gesell was sharply critical of the government's delay in responding to Weisberg's request for more than 50 days. The Justice Department offered him a reduced rate of 6 cents a page last week, but Gesell said, "it is apparent no consideration whatever" was given to Weisberg's claims of poor health and indigency.

"The equities are very substantially and overwhelmingly in plaintiff's favor," Gesell said. He said that the records would not be coming to light now were it not for earlier freedom-of-information litigation by Weisberg. This led to a congressional change in the law, opening the door to FBI investigatory records.

The judge, however, declined to hold up the Wednesday release, on grounds that the disclosure of the documents was the "pre-eminent consideration." Weisberg's lawyer, James H. Lesar, said later that he understood the FBI would mail Weisberg copies of the forthcoming 40,000 pages the same day.