MOSCOW, JULY 28 -- West German teen-ager Mathias Rust, who shocked the Soviet leadership by landing a small plane in Red Square two months ago, will be tried within a month on charges carrying penalties of up to 10 years in prison, Soviet officials said today.

Rust, 19, whose exploit May 28 led to the retirement of the Soviet defense minister and ouster of the air defense chief, will be charged with illegal crossing of Soviet borders, violating international flying regulations and aggravated hooliganism, a West German Embassy spokesman said, quoting a Soviet investigator.

Diplomatic sources said the first charge carries a maximum penalty of 10 years in prison and a fine of 1,000 rubles -- about $1,600. They said the hooliganism count could bring a prison sentence of up to five years and the international flying violation a three-year sentence. Under the Soviet criminal system, sentences are usually served concurrently.

Foreign Ministry spokesman Gennadi Gerasimov said the principal issue of the trial would likely be "the degree" of Rust's guilt. "Nobody doubts" that Rust violated laws, Gerasimov said at a news conference.

The announcement of the charges was in line with previous indications by Soviet officials that Rust would be tried, despite occasional hints that his case would be handled with leniency. However, the three criminal counts went beyond the charge of border violation that authorities earlier had suggested was the minimum case he faced, and appeared to underline the seriousness with which the Soviet leadership treats the affair.

The Hamburg teen-ager, flew from Helsinki to Moscow in a Cessna, avoiding Soviet interception throughout the five-hour flight and landing just outside the Kremlin.