Barbara Gladstone, an art dealer whose eye for spotting talent and knack for nurturing it helped her to build one of the largest and most influential contemporary art galleries in New York, died on Sunday in Paris. She was 89.

Her gallery said her death, in a hospital, was caused by an ischemic event, whose symptoms are similar to those of a stroke. Ms. Gladstone, who was on a working trip to Paris, lived in Manhattan.

Ms. Gladstone represented more than 70 artists and estates, including Americans like Robert Rauschenberg, Keith Haring and Elizabeth Murray; the provocative video and installation artist Matthew Barney; pivotal figures of the Italian Arte Povera movement like Mario Merz and Alighiero Boetti; Richard Prince, the pioneer of photographic appropriation; the diffident realist painter Robert Bechtle; the Iranian American filmmaker and photographer Shirin Neshat; and stars of more recent vintage like the sculptor Wangechi Mutu and the photographer LaToya Ruby Frazier.

What brought these disparate artists together on her list was her abiding interest in them personally and the devoted way she husbanded their work.

“At the core,” Mr. Barney said in a phone interview, “Barbara was a romantic.”

He recalled the trust she showed him when he was preparing their first show together, in 1991, which turbocharged both their careers. “We made a video within the gallery and ended up having to shoot through the night because we weren’t very organized,” Mr. Barney said. “Barbara gave me the keys and said, ‘Make sure you lock up when you leave.’”