The Reagan administration, parrying Nicaragua's "propaganda blast" against the United States in the International Court of Justice, yesterday issued a 130-page report accusing the Sandinista government of supporting, training and arming leftist guerrilla forces in neighboring Central American countries.

In releasing the report, Elliott Abrams, assistant secretary of state for inter-American affairs, acknowledged that it was intended as a partial response to Nicaragua's charges before the Hague tribunal, known informally as the World Court, that the United States is waging aggression against it by supporting anti-Sandinista rebels known as contras.

The United States announced in January that it would boycott the proceedings because it does not recognize the court's jurisdiction over what the administration contends is a political rather than a legal dispute.

"The timing is not coincidental," Abrams said. "Nicaragua is in the middle of a propaganda blast, and it has chosen the World Court as its forum. They are putting out an awful lot of lies. In our view, it is timely to set the record straight."

Abrams said the report refutes Nicaragua's "lie" before the court that the Sandinista government never engaged in aggression against neighbors. Although he noted that the report contains new information derived from declassified U.S. intelligence, captured documents and statements by guerrilla defectors, reporters at his briefing immediately dubbed the report "son of the White Paper."

That was a reference to a controversial 1981 document in which the administration first detailed its charges that Nicaragua was providing arms and other aid to guerrillas in El Salvador. In that report, and in several later statements, the United States contended that the Sandinistas, shortly after gaining power in 1979, began supporting guerrillas in El Salvador and elsewhere in Central America.

The newest report is essentially a restatement of those charges, including the contention that a Salvadoran guerrilla leader visited communist capitals in 1980 to obtain promises of arms aid and arranged to have the arms smuggled into El Salvador through Nicaragua.

"With substantial Cuban assistance, the Sandinistas helped unify guerrilla groups in El Salvador, Honduras and Guatemala; provision, train, direct and advise guerrillas in El Salvador; insert guerrilla groups into Honduras, and sustain radical antidemocratic parties and associated armed elements in Costa Rica," the report said.

"By late 1980, Nicaragua was the hub of a flow of hundreds of tons of weapons from the Soviet bloc to El Salvador, serving both as staging point for insertion by air, land and sea routes," it added. "By January 1981, the rebels were armed with modern weapons, including M16s drawn from stocks left behind by the United States in Vietnam."

In one new piece of substantiating testimony, the report quoted a Salvadoran guerrilla defector as saying he was part of a force that prepared for a successful 1983 attack on a Salvadoran army base with practice maneuvers in Cuba, using a model of the garrison constructed from sketches. The report added that the weapons and explosives used in the actual attack were sent to El Salvador through Nicaragua.

The report said these activities demonstrate why the United States was forced to conclude that its attempts to deal with Nicaragua through friendship and diplomatic negotiation were not working and that support for the contras, or counterrevolutionaries, was necessary to put "effective pressure on the Sandinistas to halt their policies of aggression, achieve internal reconciliation and contribute to regional peace . . . . "