Picasso's 1932 work "Femme assise pres d'une fenetre" . (Getty)
A portrait of Picasso's lover Marie-Therese Walter has been sold in London $43 million.
The colourful and curvaceous "Femme assise pres d'une fenetre" (Woman sitting by a window), painted in 1932, was sold at a crowded salesroom to an unnamed telephone buyer, a Sotheby's spokesman said.
It had been expected to go under the hammer for between $37 million and $52 million.
"We are delighted that this stunning and monumental portrait, which is part of the defining series that introduced his 'golden muse' to the public eye, fetched such a strong price," said Helena Newman, chairwoman of Sotheby's impressionist and modern art department in Europe.
"This particular portrait is a striking and notably modern-looking work from one of the artist's most celebrated periods."
Picasso met his famous muse in Paris in 1927, when she was 17 and he was 45. Their relationship was kept secret for many years because of her age and Picasso's marriage to the Russian ballerina Olga Khokhlova.
The affair was revealed in 1932 when portraits of Walter were displayed for the first time alongside other works by the Spanish master in a major retrospective, and Khokhlova realised there was another woman in her husband's life.
Walter, who inspired several of Picasso's works including "La Lecture, "La Reve" and "Nature morte aux tulipes", bore the artist a daughter, Maya.
"In recent years in particular we have witnessed the remarkable allure of Picasso's portraits of Marie-Therese to collectors," Newman said.
Another portrait of Walter from the same series, "Nude, Green Leaves and Bust", held the record for the most expensive work of art ever sold at auction when it was bought for $US106.4 million in New York in 2010.
It was ousted last May when "The Scream" by Edvard Munch sold for $119.9 million.
"La Lecture" sold at Sotheby's in 2011 for $38 million, double its pre-sale estimate, while "Nature morte aux tulipes" went under the hammer in New York last November for $39.5.