PANAMA CITY, Panama (AP) _ Dame Margot Fonteyn, the prima ballerina whose infectious smile and timeless grace thrilled dance lovers for 45 years, died of cancer Thursday in a hospital. She was 71.

She had been hospitalized for eight months in Houston and for the last month at a private hospital in Panama City, said Louis Martins, an adviser to President Guillermo Endara and a friend of Dame Margot.

He said in a telephone interview it was a long illness but she did not want people to know she had cancer. "She was very noble. She didn't want people to pity her."

In Houston, she expressed the wish to die in Panama and be buried next to her husband, Roberto Arias, at Panama City's Garden of Peace cemetery, Martins said. The funeral will be Friday.

Martins said Dame Margot was very moved when he visited her at Paitilla Hospital on Sunday to give her a testimonial scroll awarded her by Panama's National Ballet. He received the awarded in her name during a special performance in her honor last Saturday at the National Theater.

Until her retirement in 1979 at the age of 60, Dame Margot was a miracle of timelessness in the mercurial world of ballet.

Her artistry was legendary, once prompting 48 curtain calls for her Sleeping Beauty with Sir Robert Helpmann in New York in 1949. Just as legendary was the partnership she formed with the famed Russian dancer Rudolf Nureyev.

Queen Elizabeth II made her a dame - the female equivalent of a knight - in 1956.

"Dame Margot was a lady wonderfully down to earth and yet with an astonishing spiritual grace," said Mikhail Baryshnikov, who danced with her several times. "I think I never knew anybody like her and very much doubt that I ever will. I certainly will never forget her," he said in New York.

Nureyev was visibly shaken when he was told of Fonteyn's death. He had just gotten off a plane in Chicago, where he is performing.

"She will be remembered as the greatest dancer ever," he said. "She will be remembered as the kindest person with great concern for everyone. I was just very happy to know her."

At London's Royal Opera House, the audience stood in silence Thursday evening to remember her classic performances there.

"She was the complete professional, a true and glamorous star both on and off the stage, and an inspired and unique artist of whom we will never see the like again," said Anthony Dowell, director of the company.

During a recent visit to New York, Dame Margot told an interviewer that personality is conveyed across the footlights.

"It shows through your movement and your dancing," she said. "I think if your personality doesn't come through, then you're a little immature as an artist."

One of her final public appearances was in May, when she was given a standing ovation in the royal box at a gala in her honor at the Royal Opera House.

Dame Margot met Arias, son of a president of Panama, in Cambridge, England, during the summer of 1937 when the Sadler's Wells Ballet was performing there and he was in college.

They saw each other in 1938 and 1939 and then not again for 14 years.

They were married in 1955 and he was made Panamanian ambassador to Britain. In 1964, when he was running for office in Panama, bullets from an assassination attempt left him paralyzed.

"It's not death I'm afraid of. It's living too long," Dame Margot had said after Arias died in 1989.

She remained to manage the ranch, trying to continue her husband's cattle breeding plans.

She retired from the Royal Ballet without a pension and reportedly had financial difficulties after her husband's death.

Born Peggy Hookham in Reigate, Surrey, the future ballerina moved to China with her family at age 9, and spent much of her childhood there.

Her ballet career began when she was spotted in the early 1930s by Dame Ninette de Valois and invited to join the Vic-Wells Ballet, now the Royal Ballet, at 14.

After two years with Dame Ninette the young Margot, who had changed her name, was dancing lead roles and soon afterward succeeded Dame Alicia Markova as prima ballerina of the fast-evolving company.

Beginning in 1959, Dame Margot was listed as a guest artist with the Royal Ballet. Three years later she teamed with Nureyev, and the two starred in the company's premiere of "Romeo and Juliet" in 1965.

Of the partnership, The Sunday Times commented last year: "If Fonteyn was grace, he was elemental power. But the Russian, (who had) recently defected to the West, was only 22; Fonteyn was 20 years older ... Chronology, it turned out, was of no importance. Once they had contracted to dance together, they became the most inspired balletic partnership of the century, adored to the point of idolatry by a public craving heroes."

Dame Margot remained as trim in retirement as when she performed her lightning fast pirouettes and delicate adagios with Nureyev.

She remained content on the ranch, greeting visitors with her husband on the large veranda of their house on the crest of a hill near the sea, near the village of El Higo, 60 miles southwest of Panama City.

She used to push him around in his wheelchair, often inviting guests to join them under an open thatched hut. In her spare time, she advised the National Ballet Company of Panama.

The couple had no children, but Arias had three children by a previous marriage and several grandchildren.

In an interview a few years before her death, she said she did not miss the limelight.

"I do not feel that there has been a drastic change in my life," she said. "I am happy here. This is home. I do not really miss the past. I do not wish I were back there."