The Phantom Of The Opera creator hopes to raise $70 million (GBP35 million) from the sale of the picture, widely known as The Absinthe Drinker, and has vowed to give it all away to good causes.
The artwork, which was painted in 1901, is currently at the centre of a bitter legal dispute in Britain's High Court. The work was dramatically withdrawn from sale at Christie's auction house in New York after a German-Jewish professor claimed his family had been forced to sell it to the Nazis during the Second World War.
But now Webber insists the sale will be used to do some good.
He says, "I'm hoping to sell it for GBP35 million. And it's all going to go to theatre charities."
Source: WENN