PARIS - From the Picassos that graced his walls to historic artifacts and hundreds of sculptures, the artwork that inspired late fashion designer Yves Saint Laurent went on display Saturday, three days before it is auctioned.

Billed as "the sale of the century," the auction will disperse in three days a collection that took Saint Laurent and his lifelong partner Pierre Berge half a century to amass.

Highlights of the 733-piece collection include Piet Mondrian's 1922 painting "Composition in Blue, Red, Yellow and Black," whose squares of saturated colours inspired Saint Laurent's legendary 1965 shift dress; a wooden sculpture by Romania's Constantin Brancusi that is expected to sell for $19 million to $37 million US; and a pair of bronze animal heads that disappeared from a Beijing palace in 1860 and that China now wants removed from the auction and returned.

Other lots include sculptures from ancient Egypt and Rome and 17th century Italy, medieval ivory crucifixes and silver German beer steins that covered every available surface of Saint Laurent's homes, as well as his Art Deco furniture and even his bed.

The sale, organized by Christie's auction house, is expected to gross $250 million to $380 million. A large portion of the proceeds is to go to a foundation to support AIDS research.

Saint Laurent died in June at age 71 after a yearlong battle with brain cancer.

"In 30 years in the auction business, I've never seen anything as good as this," said Jonathan Rendell, vice-president of Christie's America. Saint Laurent and Berge "collected at the very top of every area that they bought in, the very best Modernist pictures, the very best collection of Art Deco that I've ever seen come to sale, the German silver, the cameos."

"It's really glamorous ... real luxury. The way they lived was extraordinary," Rendell said.

A pre-auction exhibition at the Grand Palais divides the pieces according to theme, although in their homes, Berge and Saint Laurent mixed it up, placing a painting from Picasso's cubist period above a delicate portrait by French neoclassical painter Ingres and covering an Art Deco side table with sculptures, intricate serving bowls and elaborate silver cups made between the 1st and 20th centuries.

The exhibition is free and open to the public through Monday afternoon -- hours before the start of sale, which will be held in six sessions over three days because of the sheer size of the collection. Hundreds of private collectors and museums from around the world are expected to bid on the lots.

Saint Laurent and Berge started collecting art in the 1950s, when the designer catapulted to fame at the Paris fashion house, Christian Dior. As their fortune grew with the launch of Yves Saint Laurent's own line, they continued to collect, working largely with private dealers and buying what caught their eye.

Some of the pieces eventually found their way onto the catwalk as the inspiration for Saint Laurent's collections. Rhododendron-shaped leaf appliques on a flowing evening gown from the designer's winter 1980 collection pay homage to Matisse, whose 1937-1938 collage "Le Danseur" is expected to sell for $5 million to $7.5 million at the sale.

The white doves on a bustier from 1988 recall the marble, bird-shaped chairs by living French artist Francois-Xavier Lalanne, which are estimated at $25,000 to $38,000.

One of the most influential and enduring designers of the 20th century, Saint Laurent is credited with helping empowered women by reinventing pants as a sleek, elegant staple of the female wardrobe. He is also remembered for his ladies' tuxedo, see-through blouses, safari jackets and glamorous gowns that remain stylish decades after they hit the catwalks.

Luxury company the Gucci Group had acquired the Yves Saint Laurent brand in 1999.

Berge has said he made the decision to sell the collection after Saint Laurent's death because without him, "it has lost the greater part of its significance."

"I cannot imagine pursuing my passion as a collector without Yves," Berge wrote in the sale's catalogue.

The auction comes at a difficult time for the art world, with the global financial crisis making buyers wary. Christie's, which has announced it is cutting 300 jobs, is betting on the sale to help reverse its flagging fortunes.