Jean Dubuffet's Visitor au chapeau bleu avril 1955 is expected to make £2m-3m ($2.6m-3.9m) at Christie's.

Dubuffet invented the term art brut (known in English as outsider art) in the late 1940s.

Jean Dubuffet founded the art brut movement

It refers to work created by those outside the established art world, an aesthetic that Dubuffet aspired to.

Dubuffet created the present work during a six month stay in the south of France; it is typically raw and childlike in its execution.

The painting is the star lot from influential contemporary art dealer Leslie Waddington's personal collection, which will cross the block in London on October 4.

Praise (1985), a work by the American minimalist Agnes Martin, carries an identical estimate of £2m-3m ($2.6m-3.9m).

The sale is timed to coincide with Frieze art week, which Waddington was instrumental in popularising.

Jussi Pylkkanen, Christie's global president, comments: ''It is a privilege to be offering works from the private collection of Leslie Waddington here at Christie's in October.

"The art dealer who pioneered contemporary art in London, long before the proliferation of galleries and art institutions in the city, Leslie introduced the art world to artists from Jean Dubuffet to Patrick Caulfield, bringing the British and European aesthetic to America for the first time, and American Abstract Expressionism to London."

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