In his recent book on "Great Male Dancers of the Ballet," critic Walter Terry singles out Ivan Nagy as "very probably the most perfect danseur noble of our day-he has the bearing of a prince, the gallantry of a cavalier, the walk of an aristocrat, the sensitivity of the poet." Few observers would care to contradict him.

Nagy also has a gift for waspish bons, mots, mostly aimed at himself. Tonight at Kennedy Center, at age 35, he makes his last appearance, not only with American Ballet Theatre-in a special gala honoring him-but in ballet together, after a career of 29 years that put him in the very highest rank of dance artists. He's calling the occasion "the funeral."

Nagy, however, who was born the same year as Antony Dowell, and whose age is exactly midway between Baryshnikov and Nureyev, is perfectly assured about his decision to retire from the stage.

"I always prayed," he says, "that I'd have the strength to get out graciously. I've never been jealous of others, but you never can tell and I'm afraid of bitterness, which I hate. I see a new generation of dancers coming up-I look around a ballet classroom at 65 or 70 dancers and see I'7 the oldest. I feel like a wax museum piece. I know I could go on a few more years, but I think, given my limitations, I've reached my peak. Being a male chauvinist pig, I feel very responsible to my family, and fortunately I'm psychologically young and strong and energetic enough to try a second career. I really have no desire to wait around till all I can do is 'character roles,' and have to beg for a Sunday matinee spot-it's a matter of self-respect."

Perhaps because Nagy has played a prince so often he has come to look like one, or maybe it's the other way around. In any case, his handsome appearance-tall, spare, with classic features and glinting green eyes-has suited him naturally to the leading roles of the standard ballet repertory: Albrecht in "Giselle," Siegfried in "Swan Lake," Franz in "Cooppelia," James in "La Sylphide," and so forth, though his performances have spanned an enormous range of styles.

He chafes a bit, though, when he's described, as he so often is, as the "ideal partner," for his notable pairings with the likes of Gelsky Kirkland, Natalia Makarova, Margot Fonteyn and Cynthia Gregory. "It makes me absolutely mad, furious," he says, "always putting me automatically in this category. I can dance my head off and the critics write that I 'partnered so-and-so beautifully.' It's true, I suppose, I've been a basically reliable partner, But I never did much to achieve this-my 'line' and so forth-it was just there."

In a way, he feels he was doomed by fate to the shadow of ballerinas. "My temperament, my looks and my talent made me right for the so-called Prince Charming roles, I couldn't help that," he says. "But those parts are basically supportive-in classical ballet, it's mainly been the woman, up there on her point shoes with her legs bared, who's the center of attention. In 'Swan Lake,' the Prince may be on stage for three hours, but he's got three minutes of dancing to himself."

The secrets of partnering, Nagy thinks, lie in being sensitive to the musical score, and in an emotional commitment of the partners. "It's nothing sexual," he says, "but I must feel a kind of love for the ballerina. I have to believe the two of us are of one heart. Of course, this makes people outside the theater think I'm some kind of whore. Even my mother. says to me, aren't you luckly your wife is an ex-dancer who you understand this, otherwise you marriage would go down the drain."

Nagy is married to the former Marilyn Burr, an Australian-born dancer who was long a ballerina of Washington's National Ballet. They met when Nagy left Hungary in 1965 at the invitation of the National's director Frederic Franklin-he began his U.S. career here and danced with the National for three years before joining the New York City Ballet, and then ABT. His wife will be in the audience tonight with their two young daughters, Aniko and Tatjana; Nagy's mother, who was his first dance teacher, is also coming from Hungary for the occasion.

What happens after tonight's farewell performance? Nagy has an invitation to assume directorship of the Australian Ballet, and will go there in February for two months as a "guest producer." "I'm very stubborn, and at first I said I don't want even to hear about it, but after they twisted my arm for a while I said I guess I really should give it a try."

In the meantime, he's toying with sundry other options for the future. He's thought of opening a restaurant in New York ("I love to eat, to entertain and I think one can make an art of a restaurant"); he'd like to resume painting, a childhood enthusiasm, "not professionally, but for my own sake"; he wants to do more flying (he's a licensed pilot) and language study, particularly Spanish (he has a cottage in Spain); luckily, he says, "In no form or shape do I want to be a choreographer"; and he's looking forward to spending, at long last, more time with his family.

Nagy declines to answer when asked about his "favourite" roles or ballerinas, or about who in the dance world most shaped his own ideals. "The truth is I have learned from and admire all my colleagues-all those people who are crazy enough, disturbed enough and who have suffered enough to be in this unpredictable, hideous, gorgeous, beautiful profession." CAPTION: Ivan Nagy, by James M. Thresher-The Washington Post