Two more leading dancers of the fabled Russian Bolshoi Ballet Company have defected to the United States, fleeing from Soviet agents in the last hours before the dance troupe left Los Angeles for home today.

U.S. officials said that Leonard Koslov and his wife Valentina Koslov sought political asylum Sunday night just after they danced in the company's final appearance of its lengthy American tour. State Department officials said they were granted asylum today.

The Koslovs, both principal soloists with the world-famous ballet, thus join a long line of prominent Russian dancers who have opted for life in the West. The latest was Alexander Gudonov, the Bolshoi star who defected last month in New york.

This latest episode is sure to doubly embarrass already red-faced Soviet officialdom because Leonid Koslov had been picked to replace Gudonov in several key roles.

Details of the defection were sketchy, with both local and federal authorities close-mouthed. Nevertheless, some facts were learned.

The Koslovs originally contacted Los Angeles police by telephone Sunday night about defecting and were taken into protective custody early this morning at the Wilshire Division police station.

It was then that the Koslovs filed their formal application for political asylum to the Immigration and Naturalization Service. In the meantime, federal security agents took over their protection.

The official caution about the affair appeared based on two grounds: The safety of the Koslovs, and the desire to downplay any possibility of the notoriety that billowed about the Gudunov defection. A major storm developed when Gudunov's wife, also a dancer, stayed with the company. When she attempted to return to Moscow, the State Department kept her plane on the ground for more than 70 hours in New York while trying to determine if she was returning to Russia of her own free will.

The Koslovs are in their mid-to-late 20s and were making their first tour as soloists with the Bolshoi. They had been members of the corps de ballet, and made their American solo debut with a lesser company last December.

It appeared that the double defection was not impetuous but carefully planned.

The Koslovs eluded Soviet security during the bedlam that accompanied the closing performance at the immense and extremely crowded Shrine Auditorium here.

They contacted an American intermediary, who made the phone call to police initiating the defection. Because the arrangement called for the Koslovs to meet the police and federal officials this morning, the couple stayed the night in hiding with the intermediary.

Soviet officials apparently did not have a clue about the defection until the couple didn't return to their hotel soom Sunday night. When the Koslovs didn't show up the Russians became nervous, and dancers in the lobby were rushed to their rooms.

Again this morning, officials and agents counted heads in the lobby, and when it was clear the Koslovs still hand't returned, there was an agitated meeting in the middle of the large room. It was obvious that something was wrong, although ballet memebers refused to talk.

Buses left at 10:30 a.m. for the airport without the Koslovs. Left behind was an interpreter with instructions to keep them in the hotel if they returned.

Also, the hotel manager received a phone call from a Soviet official just before the chartered jet left for Moscow. The manager was told that the Koslovs had missed the plane; if they showed up they were to be kept in the hotel until Russian consulate officials arrived.

But the only item that could greet a Soviet diplomat was the suitcase left behind by the Koslovs.

While not yet stars, the Koslovs were described by many as having great potential. In fact, the couple in a dramatic pose from "The Stone Flower" adorn the back cover of the Bolshoi program.

Los Angeles Time reviewer Martin Bernheimer wrote of the couple after a performance in "The Stone Flower":

"They are fresh, attractive, promising. They dance, for the most part, with skill and valor. But they cannot etch indelible images. They do not project striking personalities. They offer correctness when what we want is eloquence."

In another performance, Leonid was judged as dancing very roughly. But by the end of the Los Angeles appearances, Koslov regained his form, and his performance -- his last performance -- improved.

When he took the first curtain call to "Romeo and Juliet" alone Sunday night, the audience went wild. It was quite a performance for a man who intended to change the course of his personal as well as artistic life.