Ernst Beyeler:Charismatic and influential art dealer who co-founded the Art Basel Fair

Ernst Beyeler was one of the world's most important art dealers, a charismatic and passionate gentleman of the trade who owed his success to a combination of luck, good judgement and friendships with some of his favourite artists. Aside from selling some 16,000 works in his lifetime, he and his wife Hildy built a personal collection encompassing some 200 pieces by 40 of the most important painters and sculptors of the last century, which since 1997 has been on public view at a specially designed museum at Riehen, near Basel in Switzerland. When choosing a picture for themselves, the deciding factor was always whether or not they would like to see the work in their own home.

Beyeler was born in Basel in 1921, the son of a railwayman. He studied economics and art history at Basel University and worked in his spare time at a shop selling antiquarian books and art run by Oskar Schloss. Upon Schloss's death in 1945 he took over the reins and, from 1951, decided to concentrate solely on art, beginning a series of more than 300 exhibitions of modern artists which ran almost non-stop for the next 60 years.

His first major acquisition was Improvisation 10 (1910) by Wassily Kandinsky, a painting for which he had to pay in instalments and which remained, perhaps for sentimental reasons as much as for its beauty, in his personal collection for the rest of his life. In the early 1960s he was fortunate to acquire 340 works from the American collector G. David Thompson, establishing Beyeler's reputation as a new force within the art business.

In 1966 he had the art dealer's dream opportunity when Picasso, already a friend, invited him to his studio in Mougins, Provence, and allowed him free choice of any of the works there. He went away with 45 of them for a show at his Basel gallery, later purchasing 26 as stock, including Femme (Woman, 1907) for his personal collection. During the late 1960s he became involved with founding and organising the first annual Art Basel fair, inaugurated in 1969, which has since gone on to become the most important fixture in the art-world calendar.

Beyeler and his wife established the Beyeler Foundation in 1982 as a vehicle for their expanding personal art collection. In 1989 this collection was exhibited to the public for the first time at the Centro de Arte Reina Sofía in Madrid. The great success of this show, and a further public outing at the Neue Nationalgalerie, Berlin, encouraged the couple to consider creating a permanent exhibition space for their works.

Construction began on the new gallery, designed by the architect Renzo Piano, in 1994 and the Beyeler Foundation museum at Riehen opened in 1997, covering more than 3,700sq m of exhibition space. Speaking at the opening Beyeler said: "I have always perceived works of art as parables of creation – 'analogous to nature' as Cezanne once said – as an expression of joie de vivre."

There followed a dazzling array of exhibitions including Roy Lichtenstein (1998), Christo and Jeanne-Claude (1998-1999), Rothko (2001), Francis Bacon (2004) and Picasso (2005). By 1999 the museum was already running out of space, so an extension was created. This new area was used to especially dramatic effect in 2002 to show Monet's Nymphéas (Water Lilies), huge paintings which could be seen at their very best in the bright, airy space that the building provided.

At the time of his death he had been involved in the planning for two forthcoming retrospectives at the Beyeler Foundation this year: Jean-Michel Basquiat and Vienna 1900, centred on works by Gustav Klimt.

Marcus Williamson

Ernst Beyeler, art dealer: born Basel, Switzerland 16 July 1921; married 1948 Hilda Kunz (died 2008); died Riehen, Switzerland 25 February 2010.