Subterfuge and sleight-of-hand were not involved when the Senate last week quickly and quietly suspended limits on members' outside incomes, Majority Leader Robert C. Byrd said yesterday.

Responding to criticisms of the Senate action, Byrd said there had been ample forewarning and anyone who had paid attention would have known the matter was due on the floor last Thursday.

But with no debate and no roll-call vote -- Byrd himself left the floor just before the voice vote -- the Senate suspended a strict limitation that was to have taken effect last Jan. 1.

That limit would have restricted a senator's outside income to $8,625 annually -- or 15 percent of a senator's salary of $57,500.

Thursday's action, however, delayed the effective date of the limitation to at least 1983 and left in effect an earlier limit of $25,000 that applies only to income from speeches given outside the Senate.

David Cohen, president of Common Cause, which pushed for the new limitation, reacted to the vote by saying, "They took the money and ran."

It was nothing of the sort, Byrd told reporters yesterday at his weekly press conference. He had reversed his own support of the strict limit, he said, because he feels outside income and possible conflicts of interest are protected by "adequate" disclosure requirements.

Byrd also said he believes increased U.S. economic aid to Turkey will be "right up front" as an issue when and if the Senate takes up a strategic arms limitation treaty (SALT) with the Soviet Union.

The question of verification of Soviet compliance with a SALT pact -- already hotly debated -- is closely related to economic and political conditions in Turkey, Byrd said.

He said the loss of U.S. intelligence gathering stations in Iran increases reliance on Turkey, where electronic monitoring facilities also listen in on activities within the Soviet Union.

Stability and development in Turkey, "a democracy, pro-Western and strategically located," Byrd said, would be enhanced with more U.S. economic help.