N.Y. City Ballet delights London audiences

''You either love them or hate them,'' said the gray-haired Englishwoman sitting in the (STR)21 ($31.50) seat beside me. Clearly she was in some difficulty with the New York City Ballet Company on its latest European tour (London, Copenhagen, Paris): ''I'm trying to love them - I've been here three times already this week - but I still find their style ugly. Their arms are so angular and severe.''

But she was heavily outnumbered by other balletgoers here.

Earlier the same day, Barbara Neuman, author of the ballet book ''Striking a Balance,'' was one who had sung the company's praises. Pausing in amazement when I told her that I had never seen them perform, she said, ''Just imagine what thrills and joys await you . . . I envy you the experience . . . .''

The company - product of the late choreographer George Balanchine - was at the Royal Ballet Company at Covent Garden for two weeks, its fifth visit since 1950. With a style so unlike that of the usually conservative, purist Royal Ballet Company (''my idea of a perfect company,'' the Englishwoman had added), the US dancers still received rave reviews.

Headlines read ''Welcome back,'' ''Movement to a magic formula,'' ''Top form, '' and ''A new generation of generous genius.''

In the London Sunday Times, David Dougill began his article this way: ''Bliss is to have the New York City Ballet back at Covent Garden.''

Veteran critic Clement Crisp waxed lyrical in the pink-colored sheets of the respected Financial Times, starting off with, ''I think Balanchine's 'Divertimento No. 15' (based on the Mozart work) a near-perfect work of art.'' He ended, ''(The NYB season) is a joy not to be missed.'

For this first-time viewer, the impression was one of exhilaration and admiration for the energy, dedication, and sheer enjoyment of dancing expressed by everyone on stage.

At no time during the evening was there a feeling that the works had been performed before. The dancers attacked the choreography with the same vigor and zeal that one sees at the performance of a new work.

Yes, the arms were angular, and some of the movements unexpected. But the thin, shapeless bodies and long, long legs of the ballerinas achieved nonstop fluid motion, making the evening one of pure delight.

Everything looked so effortless on stage. Yet that morning I had sat in the wings watching various dancers rehearse not only their movements but, more so, their timing. Concentration was evident on flushed faces as they mouthed aloud the beats of the particularly hard tempos of Stravinsky's ''Agon.''

Dressed in white Levi's and tennis shoes and a collarless, striped shirt, Peter Martins, the ballet in chief (a role he shares with Jerome Robbins), stopped and started the various rehearsal excerpts behind a closed curtain on the main stage.

The Danish-born Martins will retire from dancing after this tour to devote his full time to directing the company. He has been a principal since 1970, has choreographed pieces for the company, and since 1981 worked alongside Balanchine until the founder's passing earlier this year.

The evening program began with the ''Divertimento No. 15.'' ''What an introduction to the company,'' marveled Ms. Neuman. Balanchine wrote that the score was the one he admired most in the world, describing it as one of many pieces written for special occasions ''to divert and charm audiences that expected to be entertained.''

And charm it did. Elegantly and with great feeling for every nuance of the music, five principal women, three men, and eight corps de ballet members interpreted the various movements.

A sky-blue backdrop on a setless stage and simple classical tutus that resembled decorated birthday cakes set off the complete freedom and precision of the dancing. Most of the audience (though not the woman beside me) sat bolt upright, transfixed by the action on stage.

Of special note was the outstanding partnering. It appeared that the dancers were linked by some invisible thread that drew them smoothly and naturally to one another.

Returning for the final matinee, I saw those particularly hard tempos of ''Agon'' danced with a remarkable oneness of music and bodies.

The grand finale was an exciting, brilliant, and beautiful ''Symphony in C,'' by Bizet. The company left England in glory.