OSLO, JULY 30 -- The Norwegian government has ordered a Soviet diplomat and three trade delegates to leave the country, accusing them of gathering high-technology intelligence for the KGB, Foreign Minister Thorvald Stoltenberg said today. He said the expulsion orders were issued July 15, but kept secret for two weeks in hopes of preventing a retaliation by Moscow.

But the Soviet Union declared two Norwegians -- a diplomat and a former staffer at Norway's Moscow embassy -- persona non grata three days ago, Stoltenberg said.

"The Norwegian government regrets the Soviet behavior in this affair. We cannot accept that illegal intelligence activities are carried out in Norway," Stoltenberg said.

In Moscow, a Soviet Foreign Ministry official said he knew nothing about the Norwegian action, and declined further comment.

Stoltenberg identified the diplomat as Valentin Korpusov, a second secretary. He said three of the four Soviets had already left Norway and the fourth should leave soon."

Justice Minister Helen Boesterud said the four had shown interest in companies dealing with offshore oil exploitation, and underwater optics and acoustics.

"For years they have hunted for company secrets at smaller Norwegian high-tech companies and tried to establish contacts with people within Norwegian industry, even suggesting meeting them in third countries," Boesterud said.