A sketch by Pablo Picasso (search) of his mistress reclining nude sold for $575,357 — about three times the estimated price — at a Paris auction Monday where the woman sold 20 of the artist's works.

Describing the pencil on paper sketch in the sale catalogue, Genevieve Laporte (search) recalled how she had fallen asleep just as Picasso was preparing to draw: "He waited patiently until I opened my eyes to continue his sketch!"

The Picasso Museum (search) in Paris bought the sensual image entitled "Odalisque" (search) for about three times the estimated price, Artcurial auction house said. Altogether, the sale of Laporte's collection reaped a total of $1.87 million.

A similar sketch, entitled "Le Songe," was sold to an unidentified British collector for $507,239, more than twice the estimated price, said Francis Briest, the auctioneer.

"I am so happy, because it has been over 50 years that I have had them," said Laporte, who had a two-year secret affair with Picasso in the 1950s, when she was in her 20s.

Laporte, now 79, told The Associated Press in an interview this month that she kept the sketches Picasso gave her in a safe because she was worried about thieves — but now was ready to part with them.

"I'm at the end of my road," she said.

The two had their on-and-off affair when Picasso was with the painter Francoise Gilot, the mother of two of his children.

The sketches show Laporte. Most were drawn when Picasso took a break from Gilot in the summer of 1951 to vacation in St. Tropez with Laporte, the poet Paul Eluard and his wife Dominique.

Many sketches from the vacation bear the inscription "For Genevieve."

One Cubist-style drawing shows Picasso's face hidden in Laporte's tangled hair. When the Hermitage Museum in St. Petersburg showed the sketches, it called them his "Genevieve period," or "Tender period."