Auctioneers unveiled the most expensive art collection ever to go under the hammer on Wednesday, which belonged to Microsoft co-founder Paul ­Allen and is valued at $1 billion.

Five centuries of touchstone works featuring some of the most significant creators in history are being sold in November. 

The collection of more than 150 pieces includes works by Vincent van Gogh, Claude Monet, Paul Gauguin and Jasper Johns.

"I think this is a sale that sort of exhausts superlatives," said Johanna Flaum, vice chairman of 20th and 21st Century Art at Christie's.

"This is... the most valuable collection ever sold at auction. It's really a once-in-a-generation type of event."

Highlights include La montagne Sainte-Victoire by Paul Cezanne, which is expected to fetch at least $120 million, and Verger avec cypres by Van Gogh, whose hammer price is estimated at over $100 million. 

Allen co-founded Microsoft with Bill Gates in 1975, becoming fabulously rich as the company grew into the computing behemoth it is today.

By the time he died in 2018 at the age of 65, he had bought some of the most important works created in the last half a millennium.

The previous most expensive collection sold at auction was the Macklowe collection whose two tranches netted $922 million.

The auction will take place in New York on November 9 and 10. 

All proceeds due to ­Allen's estate are to be ­dedicated to philanthropy, in line with his wishes.

Parts of the collection will be available for public viewing in Los Angeles, London, Paris, Shanghai and New York ahead of the sale.