"I am sorry that I have been forced to make this revelation now," Ashe, 48, said at a hushed news conference that he called the day after a reporter for USA Today confronted him about his illness.

Ashe said that he would have had to lie to protect his family's privacy, which he and a few close friends had guarded since he discovered he had the disease in 1988. "No one should have to make that choice," he said.

"I don't like doing this under duress," he said. "It makes me angry. It's unnecessary."

Ashe said he contracted the virus from tainted blood transfusions he received during open heart surgery in 1979 or in 1983, several years before public blood supplies were routinely tested for the AIDS virus.

With his wife, Jeanne, standing stoically behind him, Ashe said that she and their 5-year-old daughter, Camera, were in excellent health and did not have the AIDS virus.

Ashe appeared slender and tired but as composed as he was on the tennis court when he was the world's top-ranked player. His voice broke only when he began to describe how he planned to prepare his daughter for the "sometimes cruel comments that have very little to do with her reality."

He said that he was not sick, although he was undergoing extensive treatments, including antibiotics and AZT.

The first black man to win one of tennis' Grand Slam tournaments became the second prominent athlete in recent months to announce he had become infected with the AIDS virus.

In November, Magic Johnson, the incandescent basketball star, announced his retirement from the Los Angeles Lakers after learning that he had contracted the virus that leads to AIDS. Johnson said he believed he had contracted the human immunodeficiency virus, or HIV, through heterosexual intercourse.

Ashe said that he would join Johnson to publicly campaign to raise awareness and compassion about AIDS.

Unlike Johnson, Ashe discovered his illness only after it had already progressed into AIDS.

Ashe coolly and clinically described how he lost the ability to move his right hand in 1988. A CAT scan of his brain revealed a mass that his physicians initially feared was either stroke damage or a tumor.

After exploratory brain surgery, doctors determined that Ashe instead was suffering from toxoplasmosis, a disease that damages the nervous system and that is considered a red flag for AIDS. Blood tests revealed he had the virus.

Ashe said that he and his family decided to keep knowledge of the disease private. "I wasn't ready to go public with it because I had some things I wanted to do unfettered, so to speak," he said.

Since learning that he had the disease, Ashe completed his third book, A Hard Road to Glory, a history in three volumes of black athletes in America.

He has also written a column on tennis and has appeared on television as a tennis commentator. The news conference yesterday was held at the headquarters of HBO, the cable channel for which Ashe works.

Ashe was accompanied at the news conference by his physicians and friends, among them New York Mayor David N. Dinkins, a tennis buff who has known Ashe for many years.

Ashe said he had also received telephone calls yesterday from President Bush and L. Douglas Wilder, the governor of Virginia, where Ashe was born.

Ashe, the son of a Richmond park maintenance worker, won the National Interscholastic Tennis Championships as a high school star in 1961.

He graduated from UCLA in 1966 and spent two years in the Army before he turned professional in 1968 at age 26. He instantly became the top-ranked player in the world.

Ashe scored his greatest triumph in 1975 when he became the first black man to win Wimbledon, defeating the flamboyant Jimmy Connors.

Meanwhile, Ashe became active politically. He was arrested in an anti-apartheid protest outside the South African Embassy in Washington in 1985, and helped lead a boycott of athletic events in South Africa.

In 1979, while making a comeback in the tennis world at age 36, Ashe was struck down with a heart attack after conducting a clinic for young tennis players in the Bronx.

He underwent a three-hour quadruple bypass operation at St. Luke's Hospital in New York in December 1979.

Ashe had the second bypass operation in 1983 after he suffered from angina. Two days after the surgery, Ashe said he accepted a doctor's advice to receive two units of blood to speed the recovery process. He believes it was that transfusion that infected him.

About 4,770 AIDS cases in the United States have been attributed to transfusions of blood or blood products, about 2 percent of the total. Almost all those infections occurred before the nation's blood supply began being screened for HIV in 1985.

Ashe said he had no plans to take legal action. "I am not suing," he said. "It doesn't do any good."

Ashe said only he and a small circle of friends knew he had AIDS.

"I have had it on good authority that my status was common knowledge in the medical community, especially here in New York City," he said. "And I am truly grateful to all of you, medical and otherwise, who knew but either didn't even ask me or never made it public."

Ashe said that he came to rely on "a silent and a generous conspiracy to assist me in maintaining my privacy."

But last week, USA Today learned about his condition. "Somebody just called and ratted on me," said Ashe. On Tuesday, a reporter confronted him with the information. Ashe and his wife, after a sleepless night, reluctantly decided they had to go public.

"I didn't commit any crime," Ashe said, under the hot blaze of a roomful of television cameras. "I'm not running for office. I should have the right to maintain my privacy."

A USA Today editor yesterday contended the newspaper was justified in pursuing a tip that Ashe has AIDS because he is "a public figure far beyond the world of tennis."