Experts estimated that Lauder's painstakingly put-together trove immediately catapults the Met into the forefront of world collections of Cubist art, equal or even ahead of renowned institutions like the Museum of Modern Art, also in Manhattan.

"In one fell swoop this puts the Met at the forefront of early-20th-century art," Campbell told The New York Times. "It is an (irreproducible) collection, something museum directors only dream about."

Forbes magazine said the collection was worth about $1.1 billion and that Lauder had therefore given away 13.5 percent of his $8.1 billion personal fortune. It also "enshrines him in the pantheon of the most generous philanthropists of all time", Forbes said.

According to the magazine, which specializes in tracking the super wealthy, Lauder becomes the 24th individual in the world to donate more than $1 billion over the course of their lifetimes.

"He now stands shoulder to shoulder on that list with the likes of Bill Gates, Warren Buffett, Eli Broad, George Kaiser, Michael Bloomberg, George Lucas and others," Forbes reported.

The collection "distinguished by its quality, focus, and depth", includes 33 Picassos, 17 works by Braque, and 14 by Gris and Leger apiece, the Met said in its statement.

Among the masterpieces are paintings that were critical to the revolutionary early 20th century artistic movement of Cubism. Highlights include Picasso's The Scallop Shell (Notre avenir est dans l'air) from 1912, and Woman in an Armchair (Eva), from 1913.