The Justice Department has asked the West German government to find and then extradite three associates of political extremist Lyndon H. LaRouche Jr. who are scheduled to go on trial Monday on criminal charges, but who are still fugitives in Europe.

Assistant U.S. Attorney John Markham, who is handling the prosecution in Boston, said the West Germans are searching for the three LaRouche fund-raisers, Michael Gelber, Richard Sanders and Charles Park. Each faces credit card fraud and obstruction-of-justice charges in connection with LaRouche's 1984 presidential campaign.

The charges of obstruction of justice -- against LaRouche himself, the three fund-raisers and eight other associates -- center in part on the group's alleged efforts to send the three out of the United States and keep them in Europe soon after the FBI started an investigation in 1984.

At the request of the U.S. prosecutors, West German authorities have interviewed several LaRouche associates there in an effort to find the fugitives.

LaRouche group lawyers have filed motions in Boston to have a federal judge limit the West Germans' investigation. Markham said in response on Friday that the judge should not now alter its extradition request to West Germany, in part because of recent disagreements between the two countries concerning the extradition of Lebanese terrorist suspect Mohammed Ali Hamadei.

In June the Bonn government, fearing the response of terrorist groups, refused U.S. requests to extradite Hamadei, who faces U.S. charges of air piracy in connection with the 1985 hijacking of a TWA plane and the slaying of a Navy diver.