"I'm rather surprised," said Roger Stevens. "And delighted. But I haven't a clue as to why it descended on me."

He was referring to knighthood, which descended on him during a brief lunch-time ceremony Friday at the British Embassy.Stevens' wife Christine and his British son-in-law Hugh Gough attended as Ambassador Nicholas Henderson bestowed decorations on a group of nine Americans.

The honor was not accompanied by a citation, and embassy officials were unable to explain the specific achievements that had brought it about. But Stevens' role as a producer in London and as importer of Plays by Tom Stoppard, Harold Pinter and Alan Ayckbourn is regarded a likely cause. Besides Stevens, the short list of American knights includes actor Douglas Fairbanks Jr. and S. Dillion Ripley, director of the Smithsonian Institution.

At the Kennedy Center yesterday, Stevens' associates debated whether to add the "Sir" before or after his existing title, "chairman" of the Kennedy Center. But the knight himself, after consultations with Fairbanks, has decided to leave his name alone.

"Since the U.S. doesn't recognize these, it's not official in this country," Stevens explained. He might be entitled to a "Sir" if he should happen to visit England, he said, "but I don't think I'd make a point of it.