Theatre impresario and composer Andrew Lloyd Webber is currently in talks to sell four of his 11 London theatres.
Lloyd Webber has said West End theatres should get public subsidies
The negotiations relate to four West End theatres - the Apollo, the Garrick, the Duchess and the Lyric.
A spokesman told BBC News: "Andrew Lloyd Webber has received an enquiry in relation to the acquisition of some parts of his businesses."
The deal is in the early stages, a statement said, and the identity of the potential buyer has not been revealed.
The 56-year-old composer has created hit stage musicals such as The Phantom of the Opera, Starlight Express, Cats and Evita in a 35-year career.
News of the discussions follow reports that some West End theatres - including three of the four he is considering selling - may be forced to close because of falling ticket sales.
WHAT LLOYD WEBBER OWNS
100% of Really Useful Group (RUG), which produces and controls Lloyd Webber's shows around the world
Film arm makes movies of shows such as Phantom of the Opera film
Record label releases cast recordings
RUG publishes Theatregoer magazine
RUG owns 50% of Really Useful Theatres, which owns 11 West End venues and manages another
Lloyd Webber has estimated £200m pre-Raphaelite art collection
Total fortune valued at £400m
Last month, the Theatres Trust produced a report saying the West End's 40 theatres needed £250m for a major refurbishment programme to bring them into the 21st Century.
The health of the capital's theatreland is to be investigated by a House of Commons committee, which will examine whether more public money should be spent to help commercial West End venues.
There are reports that Kevin Spacey - who is now the Old Vic's artistic director - may be enlisted to give evidence to the House of Commons culture select committee in coming months, along with Dame Helen Mirren and Alan Bennett.
At the end of 2003, Lloyd Webber said commercial theatres could not compete with grants given to subsidised venues.
He argued central London's theatres were crumbling while state-backed venues picked up grants for revamps, saying: "We are not on a level playing field with the public sector."
REALLY USEFUL THEATRES
1. London Palladium
2. Her Majesty's
9. New London
10. Theatre Royal Drury Lane
12. Gielgud (managed by RUG)
And in December 2004, he told a newspaper his theatre empire was not in profit.
"Everyone thinks we've got a fortune hanging around, but in actual fact the company's got a big debt," he said.
"I'm a very, very bad businessman and I don't think I've always been very well advised."
He has appointed management firm Ingenious Media - headed by ex-Really Useful Group chairman Patrick McKenna - to advise him on the current negotiations, the statement said.
"The process is in its formative stages and no decisions have yet been made. The Really Useful Group and Really Useful Theatres continue to operate as normal."
His other seven theatres are the Palladium, Theatre Royal Drury Lane, the Cambridge, Her Majesty's, the Palace, New London and the Adelphi. Really Useful Theatres also manages the Gielgud.
Lloyd Webber's latest musical, The Woman in White, opened at the Palace in September.