Angel Fernandez de Soto was said to be elegant and always surrounded by women

The Spanish artist's 1903 Blue Period portrait of close friend Angel Fernandez de Soto was bought by Lord Lloyd Webber in 1995 for �18m.

He has said the November sale will raise funds for as yet undecided good causes, including the theatre and arts.

"The sale of my Picasso masterpiece may not be a Warren Buffett, but hopefully be a mini buffet," said the musician.

"If the picture sells successfully, it will be fantastic to have a charitable fighting fund with the freedom to support other excellent causes, particularly in the theatre and music worlds.

"I am passionate about the training and education of young performers," added Lord Lloyd Webber.

Colourful

At the time of the painting's purchase more than 10 years ago, the composer called it the "proudest moment of my life" and said the artwork was "mesmeric".

De Soto was a close friend of Picasso around the turn of the 20th century and the pair briefly shared a studio.

It is said that the arrangement had to come to an end as De Soto's love for entertaining made it impossible for Picasso to paint at night when he was his most productive.

Despite meagre means, he became a colourful and well-known figure in Barcelona.

Picasso remained friends with De Soto until 1938, when De Soto was killed during the Spanish Civil War.