If this man is so rich, how come he's selling his art collection?

Musician Eric Clapton is selling his paintings in order to make room for more. While his collection of 20th century art is expected to fetch as much as pounds 500,000, it is not the money he needs, but wall space.

Rather than put the pictures, drawings and sculptures which decorate his large Chelsea home into storage, the guitar legend has decided to put them under the hammer instead. On 29 May, Christie's will auction most of the collection he has assembled over the past five years in a sale of contemporary art in London.

"He's clearing wall space rather than anything else," said Monica Campos, a specialist in contemporary art at Christie's in London. "The collection consists of a few artists in great depth and he would like to move into other collecting fields. Because they are big, big paintings - several measure approximately two metres by two metres - really it's a matter of having the space to acquire new art."

Clapton is a shrewd and serious collector. Paintings by the op-art and abstractionist English painter, Bridget Riley, and by the Italians Sandro Chia and Mariani, show a strong interest in key figures of the past few decades.

He also collected Matthew Smith - one of the most luscious and sensuously enjoyable of the English 20th-century post-impressionists, and has drawings by Matisse, Degas and de Chirico.

In dispensing with his collection, Clapton joins a list of celebrities who have parted with their art after being bitten by the collecting bug. In 1994, Barbra Streisand's collection of 20th century art deco fetched pounds 4.1m at Christie's in New York. Writing in the catalogue foreword, Ms Streisand explained: "I'm at a whole new place now... I want to simplify my life. I want only two houses instead of seven."

In 1988, Elton John's collection of art deco was sold for pounds 4.8m at Sotheby's, following a preview in the Victoria & Albert Museum in London.

Unlike prominent private collectors of 20th century art, such as Madonna and Jack Nicholson, Clapton's passion has been kept quiet. "It wasn't publicly known because it was more his personal collection to decorate his home. He was not building a foundation like other collectors do," said Ms Campos.

His aesthetic taste gets full marks from the auctioneers. "As with his music," said Ms Campos, "his taste is eclectic, highly personal and strongly rooted in tradition. It has been assembled by someone who has not been affected by the vagaries of fashion."

The collection is estimated at pounds 300,000 to pounds 500,000. The most valuable works are Riley's Sheng Tung, "a shimmering and hypnotic canvas", and Chia's The Handgame, both estimated at pounds 30,000 to pounds 40,000.

The "personal touch", reflected in the cross-section of styles and media, is, according to Ms Campos, encouraging for the art world.