NEW YORK - One of the 20th century's most well-known and luminous portraits, a gold-flecked 1907 Art Nouveau masterpiece by Austrian artist Gustav Klimt, was acquired Monday for a record sum of $135m. by cosmetics magnate Ronald Lauder. The painting, which depicts Adele Bloch-Bauer, a Jewish woman who hosted a prominent Viennese salon and was the wife of sugar industrialist Ferdinand Bloch-Bauer, has had a controversial history. It was stolen by Nazis during World War II and was recently at the center of a six-year-long legal dispute between the Austrian government and a niece of Bloch-Bauer, Maria Altmann, who claimed she and her family were its rightful owner. After winning her suit in January, Altmann decided to sell the painting. The New York Times cited anonymous sources saying Lauder paid $135 million to acquire the portrait for the Neue Gallerie, the small museum of German and Austrian modern art that he established in 2001 on Manhattan's Upper East Side. This will make Adele Bloch-Bauer I the most expensive painting ever sold, surpassing the $104.1m. paid for Picasso's 1905 Boy With a Pipe (The Young Apprentice) in an auction at Sotheby's in 2004. Klimt and Adele Bloch-Bauer were friends, and rumored to be lovers, when her husband commissioned the painting. It is a stunning example of Klimt's style, contrasting her pale, soft face and bright red lips with a background of shimmering gold. It was painted during a period when the artist was inspired by the gold leaf he saw in a 1903 visit to the Byzantine mosaics of Ravenna. The portrait took him three years to complete. Before Adele Bloch-Bauer died of meningitis in 1925 at the age of 43, she requested that the portrait and four other Klimt works owned by the couple be bequeathed to the Austrian government after her husband's death. But in 1938, when Germany annexed Austria, Ferdinand Bloch-Bauer was forced to flee and leave behind the family's art. The Nazis grabbed the paintings along with all his other belongings. Before he died in 1945, Bloch-Bauer, childless and in exile in Switzerland, annulled all previous wills and left his possessions to his only heirs, the three children of his brother Gustav. Of the three only Maria Altmann, 90, is still living. She escaped to Los Angles during the war and has lived there since 1942. Altmann fought for decades to retrieve the painting from the Austrian Gallery in the Belvedere Palace in Vienna, where the Nazis put it. Although she received restitution for some of the family's possession following the war, the Austrians said Adele Bloch-Bauer's original will giving the government ownership was still valid. In 2000, Altmann began her court battles, fighting for the right to sue Austria in US courts. The case went all the way to the US Supreme Court, which in June 2004 ruled in favor of Altmann. Still, it was only at the beginning of this year that an arbitration tribunal in Austria finally granted her and her family the five Klimt paintings that included the portrait of her aunt. The four other paintings include a second portrait of Adele, from 1911, as well as three landscapes: Beechwood (1903), Apple Tree I (circa 1911) and Houses in Utterach on Lake Atter (1916). Lauder has remained close to Altmann throughout her legal battles and in a statement released Monday she expressed satisfaction that the painting would now be displayed at the Neue Gallerie. "It was important for the heirs and for my aunt Adele that her work be displayed in a museum," Altmann said. Lauder's museum will exhibit the five paintings, which are currently on loan to the Los Angles Museum of Contemporary Art, from July 13 to September 18. Their credit will read, simply: "This acquisition is made available in part through the generosity of the heirs of the Estates of Ferdinand and Adele Bloch-Bauer."