PURCHASE, N.Y. (AP) – Allan Stone, who used his Manhattan gallery, his obsessive collecting and his exuberant personality to encourage emerging artists while becoming an expert in Abstract Expressionism, has died at age 74.

Stone died Friday in his sleep at his home in Purchase, his daughter, Jeremy Stone, said Monday. She said he had not been ill and had planned to travel to her home in San Francisco for Christmas.

A graduate of Harvard College and Boston University Law School, Stone was a practicing lawyer in his late 20s when he decided to switch careers and open a gallery. He had bought a Willem de Kooning drawing for $250 while at Harvard, which prompted his father to cut off funds for a while.

In a soon-to-be-released documentary film by his daughter Olympia Stone, Allan Stone says of the art business, “I couldn’t say that I intellectually decided to go into it. I sort of got sucked into it, sort of the way a junkie gets sucked into a heroin parlor.”

He championed many artists who became famous, including de Kooning, Barnett Newman and Joseph Cornell, and was among the first to show Richard Estes and Wayne Thiebaud. He represented Thiebaud for 45 years.

Another of Stone’s six daughters, Claudia Stone, who directs the Allan Stone Gallery, said he offered a one-man show to Thiebaud at about the same time he offered a less-prestigious three-man show to Andy Warhol, Roy Lichtenstein and Jasper Johns.

“People said the market proved him wrong but to him that didn’t matter,” she said. “To him it wasn’t a business and it wasn’t about commodities.”

Claudia Stone said it was her father’s “greatest wish” that the gallery continue after his death, and she said it would.

She said no funeral is planned, but there would be “a celebration of his life” some time in January in Manhattan.

“We’re going to have a party, which is what he would have wanted,” she said.

Stone is survived by his wife, Clare, his six daughters and eight grandchildren.