Libyan leader Muammar Qaddafi now has a few Soviet SA5 antiaircraft missiles at his disposal and is threatening to use them if U.S. Navy planes venture over the Gulf of Sidra, administration officials said yesterday.

Officials with access to the latest intelligence from Libya said Soviet advisers had cautioned Qaddafi against launching any of the newly arrived SA5 missiles during the current U.S. naval exercise off Libya, but that Qaddafi had replied that he would decide if and when to fire the weapons.

There has been debate in the U.S. intelligence community over whether the Soviet Union had retained command of the SA5s it sent to Libya, its second shipment outside the Warsaw Pact (the other was to Syria). Latest reports indicate that Qaddafi has control of the missiles, the first of which became operational a few days ago.

The SA5s, which have a range of about 150 miles but are ineffective against low-flying planes, are located on the Libyan coast at Sirte, officials said.

U.S. reconnaissance satellites have spotted SA5 sites at Tripoli and Bengasi but as yet there are no launchers or missiles in place there, according to informed officials.

The Libyans have been trained to operate the SA5s but still need on-site help from the Soviets, U.S. officials said.

So unsure are the Libyans of their capabilities, the officials added, that if they were to fire an SA5 on their own, they could be expected to make sure that all their aircraft were on the ground to avoid downing one by mistake.

Moscow has sent about 200 missile specialists to Libya to prepare sites and help operate the intricate gear, including radar, which goes with the SA5, officials said. Thus, any bombing of the Libyan SA5 sites would risk killing Russians and setting up a U.S.-Soviet confrontation.

The United States has two aircraft carriers, the USS Coral Sea and the USS Saratoga, conducting flight operations near Libya. But as of yesterday the planes had stayed out of the airspace over the Gulf of Sidra, which Qaddafi claims as Libyan territory. Pentagon officials said warships escorting the carriers are likely to go into the gulf to reassert international rights to that waterway.

Libya would be outgunned in any aerial dogfight with carrier planes, officials said, which may explain Qaddafi's interest in the SA5s as a way to rattle his saber.