A portrait of bookmaker Victor Chandler by artist Lucian Freud is expected to fetch up to £4m at auction.
Freud, famed for lengthy sittings for his subjects, painted Man In A String Chair between 1988 and 1989.
Mr Chandler is chairman of one of the world's biggest bookmakers and also is a long-standing friend of the artist.
The portrait goes on sale at Christie's in London on 8 February. The current record for a Freud work is £4,152,000 for Red Haired Man On A Chair in 2005.
Mr Chandler and the artist met in 1979 and they discovered that they shared a love of horse racing.
A Christie's spokesman said: "Man In A String Chair succeeds both as a frank and perceptive portrait and as a timeless representation of our modern age."