At movie screenings here in Tinselvania, people applaud everything but the Exit signs. And yet the ovations seemed spontaneous and genuine when Laurence Olivier, 71, was honored Friday with a tribute at the closing night of Filmex, the Los Angeles International Film Exposition.

Indeed the crowd jumped so eagerly to its feet for the standard standing O that Olivier, having made his way to the podium, said, "Please, I simply don't want you to get tired," and gestured for everybody to sit down. In a neatly cropped gray and white beard, Olivier could be mistaken for either a very wealthy pawn-broker or a psychoanalyst. Of course, he was mistaken for neither.

The evening included the premiere of Olivier's 60th film, "A Little Romance," which is also the first movie from Orion Pictures, a company formed last year when most of the top creative people at United Artists walked out in a king-sized huff. They were feuding with Transamerica, the conglomerate that owns UA.

Orion threw a feud party, dubbed with brazen incongruity, "a little supper" after the film's screening, and also a spokesman said, flew 50 "key" critics and show biz journalists from all over the country in for the affair.

Before the film, Olivier made a little speech that was so slavish in its humility, that one young producer at the party asked, "Was the world's greatest actor really that grateful or was he merely being the world's greatest actor?"

Considering his age and his illnesses of recent years, Olivier's most moving comment on the tribute was, "It is something which I will treasure for the rest of my days and for once in my life, I might wish they would be a little longer so I might enjoy it a little longer."

Olivier was introduced by Gregory Peck who co-starred with him in his previous film, "The Boys From Brazil." In that one Olivier watched as Peck, playing a fugitive Nazi doctor, was chewed to bits by Doberman pinschers.

Peck called Olivier "the inspiration of actors the world over" and told him, "We're all better off because of you."

In "A little Romance" Olivier plays a cuddly old pickpocket who helps two very intelligent teen-agers in Paris run off to Venice so they can smooch under the Bridge of Sighs. One party-goer observed that director George Roy Hill may have made the picture mainly so that he could have a European vacation but the audience loved the film - a cute, dewy sweetie-pie sort of a movie - and all but clapped their hands into plowshares.

They also roared at the "in" jokes in the film - scenes from "The Sting" and "Butch Cassidy and the Sundance Kid" dubbed into French. Hill directed those movies too.

When the film ended, a spotlight shone down on Olivier, who stood up with Hill and with Diane Lane and

Thelonious Bernard, the two ultra adorable kids from the film. There was more applause and then an enormous silence. Nobody moved. Olivier just stood there. Apparently somebody had forgotten to do something.

So finally a member of the audience shouted out, "God Bless Sir Laurence!" and everybody started cheering again while he was led out. Actually he is not "Sir" but "Lord" having long since been so honored by the queen.

Guests at the party included Paul Newman - carting around his customary Coors - Michael Caine, playwright Neil Simon and his actress-wife Marsha Mason, veteran director King Vidor, and rock star Peter Frampton, who wore black leather pants and white bucks. A young woman threatened to pinch his derriere as he stood near her table, laughing hysterically with actor Dudley Moore but she managed to restrain herself.

Bette Midler, whose forthcoming film "The Rose" is the talk of the town, forthcame in oodies of light with her hair now shreds and curls of angelic blondness. The entourage surrounding her was exceeded only by the moat of Orion honchos shielding Olivier.

Olivier left the party with Robert Wagner and Natalie Wood, the husband-wife acting team with whom he made a disastrous TV version of "Cat on a Hot Tin Roof." As they and those guarding them moved toward a waiting limo searchlights ravaged the sky - and the windows of the Century Plaza Hotel across the street - and photographers snapped madly away.

"You've got enough, you know you'-ve got enough," one flack shreiked at a picture-taker. But he took another one anyway as the old man was spirited into the car.