Obituary: Leo Castelli

THE NEW York art world was still a very small and provincial outpost of the international art market when the Jewish Italian-born Leo Castelli established his gallery there in 1957, but within just a few years he was acknowledged as one of the most influential art dealers in the world and as a leading player in the displacement of Paris by New York as the foremost centre of contemporary art.

Having earned a degree in law at the University of Milan, Castelli worked in insurance and banking during the 1930s while beginning to collect art, developing a particular interest in the work of the Surrealists. In 1938 he opened his first gallery, the Galerie Rene Drouin in Paris, with his wife Ileana (who, on her remarriage, as Ileana Sonnabend became a prominent dealer in her own right) and the architect and interior designer Rene Drouin. The Castellis departed for New York in 1941, leaving the gallery in the hands of Drouin, who established himself as one of the most important dealers of contemporary art in Paris.

Leo Castelli served in the US Army and continued to work in manufacturing as late as 1949. By this time he had met the New York art dealer Sidney Janis and the American Abstract Expressionist painters, such as Jackson Pollock and Willem de Kooning, who were then being lionised as the heirs to the great European modernists.

It was through his friendship with Peggy Guggenheim and exiled Europeans such as Marcel Duchamp and Matta that Castelli expanded his contacts in America, and in 1950 he organised an exhibition for Janis entitled "Young Painters in the US and France", which paired such celebrated Europeans as Jean Dubuffet, Nicolas de Stael, Matta and Pierre Soulages with the artists he regarded as their American equivalents, such as de Kooning, Mark Rothko, Arshile Gorky and Franz Kline, many of whom had themselves been born in the Old World or had been formed artistically by their contact with European models.

In May 1951 Castelli mounted "The Ninth Street Show" in the heart of New York's community of Abstract Expressionist painters, convinced that the most ambitious painters of that generation, such as Pollock, de Kooning, Kline and Rothko - all of whom had work included in the show - were yet to be given their due by American museums and collectors. Among the 60 or so artists featured in this exhibition, which in retrospect marked a turning-point in the credibility of American art, was Robert Rauschenberg, an artist then in his mid-twenties who by the end of the decade was to be represented by Castelli and to be recognised as one of the great figures in contemporary art.

Castelli was nearly 50 years old when he finally established his own New York gallery bearing his name. The opening exhibition in February 1957 - which included the work of European heavyweights such as Robert Delaunay, Alberto Giacometti, Fernand Leger and Piet Mondrian alongside de Kooning, Pollock and the sculptor David Smith - was an immediate success, but it was only with Jasper Johns's inaugural solo show in January 1958 that Castelli's true genius as a dealer became evident.

Having seen a single work by Johns, Green Target, in a group exhibition at the Jewish Museum, he was thrilled to be introduced to him three days later when visiting Rauschenberg in his studio in the same building. The encounter with Johns's flag and target paintings was, he later explained, love at first sight, and he offered Johns a solo show at that very first meeting.

Johns, who was looking for a gallery that was not obviously associated with any one style or tendency, readily agreed. The show was greeted with an unprecedented critical acclaim and commercial success, especially for an artist then aged only 27: a painting was featured on the cover of Artnews magazine, three works were acquired by the Museum of Modern Art and the reputations of both artist and dealer were made.

The Johns exhibition, like the solo show accorded to Rauschenberg's "combine paintings" a month later, was immediately recognised as the start of something new and as a radical declaration of independence from Europe. Rauschenberg's winning of the Grand Prize in Painting at the 1964 Venice Biennale, though marred by controversy, was seen as a symbolically important event marking the final triumph of American art.

The Leo Castelli Gallery quickly became the place for ambitious and iconoclastic young artists to be seen, and with Ivan Karp then working in the gallery as an additional talent scout, many of the likely stars of that generation were offered shows and the rare security of a guaranteed stipend. Among those who joined in the gallery's early days were the abstract painter Frank Stella in 1960 and Roy Lichtenstein with his paintings derived from comic strips in 1962, followed in 1964 by Andy Warhol, who had been desperate to join the gallery since the turn of the decade.

Castelli became known as the champion of Pop Art, showing also the work of Claes Oldenburg, James Rosenquist, Richard Artschwager and Edward Ruscha, but he was equally sympathetic to the work of Minimalists and post-Minimalists such as Donald Judd, Dan Flavin, Robert Morris, Bruce Nauman and Richard Serra, to the hard-edged abstraction of Ellsworth Kelly, to more painterly abstract artists such as Cy Twombly and to conceptualists such as Joseph Kosuth, Lawrence Weiner and the German Hanne Darboven.

His judgement was not unerring - as a glance through the roll- call of his exhibition programme will attest - but in his openness to new developments he epitomised and became inseparably associated with contemporary American art at its freshest and most daring. He cut an elegant figure, and visitors to his gallery could expect to see him at his desk when he was well into his eighties. With his death, an effervescent era in American art can truly be said to have drawn to a close.

Leo Krauss (Leo Castelli), art dealer: born Trieste, Italy 4 September 1907; married 1933 Ileana Schapira (one daughter; marriage dissolved 1960), 1963 Antoinette Fraissex du Bost (died 1987; one son), 1995 Barbara Bertozzi; died New York 21 August 1999.