MARINA DEL REY, Calif. (AP) _ Soviet emigre Vladas Sakalys left his homeland the hard way, walking 350 miles across electric-fenced forests, fording ice-cold marshes and throwing off tracking dogs with mothball flakes.

The defector, who works at a Los Angeles electronics company, said he once escaped detection by a Soviet military ship during his three-week ordeal by submerging himself beneath frigid waters and breathing through a reed.

Feverish and barefoot, he stumbled into Sweden on July 19, 1980.

Sakalys, 44, whose run-ins with the KGB began at age 13 when he helped print pamphlets urging ''Soviets Go Home 3/8'', was frequently imprisoned in camps in Siberia, near Moscow or in his Lithuanian homeland because of his anti-Soviet activity.

And he was again in trouble in 1980, he recalled, when he became one of 45 dissidents who signed a declaration demanding an end to the Soviet occupation of the Baltic countries. Lithuania is one of those countries; it was a separate nation before it was swallowed up by the Soviet Union during World War II.

He said the KGB picked him up on a Friday, questioned him, released him and told he would be brought back Monday to swear that his signature was a forgery - or face a possible 15 years in prison.

That Sunday, Sakalys went into hiding to plan his escape.

He told the Los Angeles Times he now feels free to speak after learning that his companion-in-escape, who changed his mind and turned back at the Soviet border, was later arrested for trying the same thing a second time and is now serving a 15-year sentence.

He recalled that he and his friend slipped onto a train headed for the northwestern border, a train loaded with drunk, rowdy soldiers, he said.

The train halted for a moment and they jumped, ran, and then walked for what Sakalys estimates was 127 miles in 10 days, sometimes waist-deep in icy water. At the first electric sensor fence near the border, they waited for the dog patrol to pass.

''I said, 'Let's go.' He said 'No, I'm afraid.' It was maybe the worst moment of my life.'' But he understood his friend's reluctance: ''I was in a desperate situation and he wasn't.''

Sakalys stood on his friend's shoulders and vaulted the fence. Before moving on, Sakalys sprinkled the ground with naphthalene - mothball flakes - to throw the dogs off his scent.

For days more, he ran, walked and swam in freezing water. On one lake he saw a cutter flying the Russian naval flag, and submerged briefly, breathing through a reed.

There was no naphthalene left when he ''decided just to run, because it was my last hope.'' When he reached Finland, it was ''the best moment of my life,'' he said, although Finnish authorities would send him back if they captured him.

At an isolated farmhouse, an elderly man fed him, gave him a cigarette, packed three pounds of rye bread and gave him a map to Sweden. Sakalys gave the man his last possession of value - his watch - and kept walking.

Ten days later, on July 19, he swam across rapids, stumbled up to a teen- age boy and asked, ''Is this Finland or Sweden?'' The boy said Tornio, Sweden.

''Telephone police,'' Sakalys pleaded. He estimates he had walked 350 miles at that time.

Swedish authorities jailed him until other Soviet emigres who had seen him in labor camps identified him. Sakalys came to the United States through an aunt in New Jersey.