Defense Secretary Caspar W. Weinberger yesterday appeared to contradict an official Pentagon statement about an errant Soviet cruise missile that flew over Finland last month, but the Defense Department stood by its statement.

Weinberger told the Senate Foreign Relations Committee that the Soviets shot down one of their cruise missiles that strayed over Norway and Finland. His statement appeared to confirm an account, denied by the Pentagon, that appeared yesterday in the London Daily Express.

"They shot down one of their own cruise missiles that got away from them and was starting to work its way across Norway and Finland," Weinberger said of the Soviets. But Pentagon spokesman Michael I. Burch said later that Weinberger was referring to Soviet capabilities, not actual events.

"The secretary did not mean to imply that the missile was shot down," he said. "The Soviets didn't shoot the missile down. It ceased to fly."

Officials speculated that the confusion may have resulted from the recent discovery of the wreckage in Finland that indicated the errant missile was a target drone and not a weapon. Officials believe that the Soviets had intended to test their defenses by shooting down the drone but that it flew off course.