MOSCOW, JULY 2 -- The general believed to have been in charge in the Soviet Far East when a Korean airliner was shot down in 1983 was identified today as the new chief of Soviet air defense forces.

Gen. Ivan M. Tretyak replaces Chief Marshal Alexander I. Koldunov, who was fired after a West German teen-ager entered Soviet airspace in a Cessna airplane on May 28 and flew unimpeded all the way to Red Square.

The unauthorized flight of Mathias Rust, 19, touched off a shakeup in Soviet military ranks, the replacement of the defense minister and harsh criticism from the ruling Politburo.

The flight also was an embarrassment to the Kremlin leadership, which long has boasted of the Soviet military's ability to detect any kind of aircraft trying to penetrate Soviet skies.

Today's edition of the Defense Ministry newspaper Red Star said Tretyak addressed the top Communist Party members of the air defense troops on their role in strengthening military preparedness.

The meeting touched on the "reliable defense of state borders," Red Star said, without specifying when or where the speech was made.

Tretyak, 64, was named commander of the Far Eastern military district in May 1976. Western military attaches in Moscow said Tretyak apparently was in that post when a Soviet fighter shot down a Korean Airlines jumbo jet in Soviet airspace.

All 269 people aboard the Boeing 747 were killed in the Sept. 1, 1983, incident, which provoked a storm of criticism worldwide.

The Soviet Union maintained that the plane was on a spy mission, and asserted its right to defend its airspace.

One military attache said that little was known about Tretyak, but his post as commander in the Soviet Far East would indicate that he was greatly trusted in Moscow.

The Far Eastern command, which has headquarters in the Pacific port of Vladivostok, contains some of the Soviet Union's largest and most sensitive defense installations.

Gen. Dmitri T. Yazov, who was named May 30 to replace Sergei L. Sokolov as defense minister, served as commander in the Soviet Far East after Tretyak.

Military attaches also said it was unclear when Tretyak had left the Far Eastern command and what his most recent post had been, but that he recently had been working in Moscow.