SAN FRANCISCO (AP) _ After learning that he had AIDS, fashion designer Halston moved to California, where he spent some of his final days touring the majestic coast around Big Sur in his new, jet-black Rolls-Royce.

The designer, who transformed fashion in the 1970s, died Monday night. His brother said Tuesday that Halston had asked that the $300,000 Rolls be auctioned off, with the funds going to AIDS research.

Robert Frowick described his brother as intensely private, but said the family wanted to hold a memorial service that would accommodate Halston's many fans and friends. It will be held Friday at San Francisco's Calvary Presbyterian Church.

The 57-year-old designer died at Pacific Presbyterian Medical Center, where he had been hospitalized with Kaposi's sarcoma since December.

''We are all deeply saddened by Halston's death,'' said Ronald Perelman, board chairman of Revlon Group Inc. in New York. ''He was an American leader of design and style who helped to define his entire era. He will be sorely missed.''

Mr. Blackwell, the acerbic fashion designer known for his annual worst- dressed celebrity list, lamented Halston's loss.

''Halston in the last several years has been conspicuously absent from the scene. His death is a tragedy,'' Blackwell said from his home in Los Angeles.

Halston's first client was Fran Allison of ''Kukla, Fran and Ollie.'' Within months he was creating hats for Kim Novak, Hedda Hopper, Deborah Kerr and Shirley Booth.

Known for his signature black and red attire, the Ultrasuede shirtdress and the pillbox-style hat worn by Jacqueline Kennedy at the 1961 presidential inauguration, Halston also designed clothes for Lauren Bacall, Liza Minnelli, Carol Channing and Bianca Jagger. He opened his own couture house in 1968.

Through his work he collected a star-studded circle of friends, including artist Andy Warhol.

Born Roy Halston Frowick, the son of an accountant and a housewife, he took to fashion early on. At age 13, he made a red hat and veil for his mother to wear on Easter. His brother, Robert, said Halston always had an innate taste for clothes.

He began working in Chicago, where he sold hats at the Ambassador Hotel before moving to New York where he joined Bergdorf Goodman in 1957.

Halston quickly rose to fashion fame and fortune in the Big Apple, earning two prestigious Coty awards for fashion.

''He was temperamental, spoiled, always threatening to quit,'' Andrew Goodman, Bergdorf's president, said in 1973. ''But we indulged him because he was so talented.''

His hallmark cardigan draped over the shoulders, slinky jerseys, caftans and other designs swept the country, and he opened a Madison Avenue boutique.

But Halston's position at the pinnacle of the fashion industry began to slip in 1973, when he signed a $16 million deal with Norton Simon Inc. for his ready-to-wear line, his couture operation and the Halston trademark.

The agreement let Norton Simon use the Halston name for products he didn't design.

J.C. Penney Co. Inc. approached Norton Simon with the idea of a line of inexpensive Halston clothes to be sold exclusively in the low-price department stores, and Halston agreed. That deal was signed in 1982.

Shortly after that, Bergdorf Goodman announced it would no longer sell Halston clothes because of the association with Penney. Adding to the designer's woes, Norton Simon was acquired in a takeover of the Esmark Inc. conglomerate by Beatrice Cos.

Beatrice canceled Halston's limousines, dismissed staff and dismantled his company.

Revlon bought use of the Halston name in December 1986, although the designer retained the right to also use it. Revlon used it on a popular fragrance line.

Diagnosed about a year ago as infected with HIV, the virus that causes AIDS, Halston moved to northern California to join family members living in Santa Rosa.

He is survived by two brothers and a sister.