MUNICH, JUNE 20 -- Hundreds of East German intelligence officers have defected since the Communist government collapsed, providing Western intelligence agencies with a gold mine of information on spies in the West and East German connections to international terrorism, according to a senior West German official.

The official said this new wave of defectors has helped the Bonn government crack spy rings and arrest suspected terrorists and has confirmed Libyan involvement in the 1986 La Belle discotheque bombing in West Berlin.

The flood of defecting East German espionage operatives and officials in the last six months, compared to fewer than a dozen last year, has raised the promise of one of the most bountiful harvests of intelligence information in years for West Germany and, indirectly, such allied countries as the United States.

Information provided by the East German officials is thought to be particularly valuable because the border between the two Germanys was for years the front line in Cold War espionage battles. In addition, East Germany was known as a frequent destination for Middle Eastern extremists seeking help with logistics and medical care.

The West German official, who is familiar with information provided by the defectors, said a number of East German agents in West Germany already have been arrested and their support networks broken up as a result of the new intelligence data handed to the West German external intelligence agency, the Bundesnachrichtendienst, or BND. He did not say whether any of those arrested were Bonn government employees, as has been the case in the past.

With help from defectors' information passed back across the border, authorities of the new East German government have arrested in the past two weeks nine West German fugitives linked to bombings and assassinations mounted by the Red Army Faction, a radical-left West German terrorist organization whose members had been protected in East Germany.

The East German State Security Ministry and the powerful secret police, the Stasi, had a long history of cooperation with Middle Eastern secret services, particularly those of Syria, South Yemen and Libya, as well as with radical Palestinian groups such as George Habash's Damascus-based Popular Front for the Liberation of Palestine and its more extreme offshoots, the official said.

Shared information on these contacts is expected to be valuable to U.S. anti-terrorism specialists. One Stasi defector has provided independent confirmation of previous U.S. intelligence that agents based at the Libyan embassy in East Berlin provided logistical help for the Palestinian bombing of the La Belle discotheque in West Berlin, according to the West German official.

The terrorist attack on the disco, on April 5, 1986, killed two American soldiers and a Turkish woman and left more than 150 persons wounded, including an estimated 50 U.S. servicemen. In retaliation, president Ronald Reagan ordered U.S. warplanes to attack Libyan military targets on April 14.

East German Security Ministry officers had prior knowledge of the La Belle bombing, although they did not help carry it out, the official said the BND has learned.

Under the new government elected last March, East Germany's policy toward terrorist groups and the secret services of nations friendly with the former regime has been reversed. An Interior Ministry spokesman in East Berlin said recently that the ministry has recalled all East German security specialists who had advised such leftist governments as that of Nicaragua's Sandinistas on airport security, personal protection and telephone tapping.

Information concerning East German espionage nevertheless has come directly from defecting intelligence officers, some of whom arrived with their files in hand, rather than from the new Interior Ministry in East Berlin. The official noted that this is not from lack of goodwill, but because the new government has been unable to get a grip on information about the former intelligence establishment.

Markus Wolf, the former head of East Germany's espionage operations, said in a West German television interview last night that the BND is reaping such a rich harvest, in part, because it is offering defectors payoffs of up to 1 million marks, in addition to immunity from prosecution. Wolf, who is wanted in West Germany for espionage, said he himself had been approached but had refused to cooperate.

In response, the BND and the Office of the Protection of the Constitution, West Germany's internal security agency, denied today that large amounts of money are being paid for information.

West German intelligence officials have no authority to grant immunity, but courts can drop charges or show leniency for East German intelligence agents who have provided valuable data, the official explained.

Chancellor Helmut Kohl's government in Bonn, preparing for unification before the end of the year, is readying an amnesty bill that would clear the slate for most of the 85,000 East Germans estimated to have worked with the Security Ministry under the Communist government, he said. The amnesty, to take effect after unification, would exclude those recruited inside West Germany or agents convicted of gross human-rights violations.

The government is still undecided, however, on how far down in the East German Security Ministry hierarchy former intelligence officers should be held responsible for departmental activity, the official said.

The West German opposition Social Democrats have suggested some terrorist acts may have been planned by Red Army Faction members in East Germany and that high-level East German officials, as well as other government figures, including former president Erich Honecker, must have known what was going on.

East Germany's democratization and the prospect of imminent unification have removed the BND's traditional espionage target -- the Communist government in East Berlin and its security apparatus.

Its remaining tasks, the senior official explained, include monitoring the 350,000 Soviet troops still in East Germany, ferreting out Stasi operatives believed to have melted into the East German army and watching for Soviet intelligence agents likely to be among the thousands of East Germans who will take up new lives in what is now West Germany after unification.