Andy Warhol's sensational portrait of Mao Zedong, considered a landmark of 20th century art, was sold to Hong Kong collector and real estate developer Joseph Lau for US$16.4 million, plus a US$1 million commission, on Wednesday night in New York, Christie's auction house said.

The portrait, entitled "Mao," set a world auction record for the artist, bringing in about US$5 million more than expected for the Switzerland-based Daros Collection, owner of one of the largest private collections of Warhol paintings.

Lau ranked 451 on Forbes' list of the World's Richest People this year. The 54-year-old self-made tycoon holds a majority stake in the Hong Kong-based Chinese Estates Holdings, and together with his brother owns SOGO Department Stores.

The "Mao" he shelled out for on Wednesday, measuring 205 centimetres by 155 centimetres and showing Mao in a dark blue jacket against a light blue background, was "literally an icon of the 20th century," said Brett Gorvy, the head of post-war and contemporary art at Christie's.

"Warhol's genius hovered over the sale throughout the evening," Gorvy said, describing the auction. "Never before had a group of Warhol works of this magnitude been presented on one auction, and it attracted bidders and buyers from around the globe."

Andy Warhol (1928-87), the American pop artist, was known for his political portraits, of which "Mao" was one of his first. Other iconic people and images to be depicted appear in paintings entitled "Lenin" and the "Hammer and Sickle."

"Mao" edged out that unforgettable Hollywood legend Marilyn Monroe on Wednesday. Warhol's "Orange Marilyn," estimated to be worth US$10 million-US$15 million, sold for US$16.2 million, including commission.

"Sixteen Jackies," a reverent depiction of an exceptional First Lady and an artistic response to the assassination of John F. Kennedy in 1963, brought US$15.7 million, including commission. In total, the eight works by Andy Warhol offered in the sale sold for a combined US$59.7 million.