A Pablo Picasso portrait, a classical pastel of a woman done by the artist in 1923, sold for $4.3 million tonight at an auction of masterworks that brought in a total of $21 million.

The Picasso, "Femme Assise au Chapeau," was bought by California's Norton Simon Museum. It was the top lot in the sale of 63 works at Christie's here and one of eight Picassos put up for auction.

"Femme Assise au Chapeau," which had been hanging in the Tate Gallery in London since 1958, was sold by the Edward James Foundation, an educational charity that had loaned the picture to the Tate.

Publisher Walter Annenberg contributed a Picasso and three other pictures to the sale. A 1925 portrait of a woman and guitar, "Femme a la Mandoline," was purchased for $1.9 million over the telephone by an anonymous buyer.

But Annenberg's rare and early Claude Monet garden landscapes sparked the most interest. At $2.1 million, "La Promenade (Argenteuil)," dated 1875, was sold to Henryk de Kwiatkowski, an airplane manufacturer and horse breeder living in the Bahamas.

"I just don't have room for the pictures. That's why I am selling them," said Annenberg through a spokesman.

A record for the artist Amedeo Modigliani was set when a portrait of a boy with red hair and turquoise eyes sold for $1.9 million. Penthouse publisher Bob Guccione, decked out in gold chains and a fur coat, placed the final bid on "Giovanotto dai Capelli Rossi" (1919). He then left the salesroom.

A painting by Georges Braque, "Paysage a L'Estaque" (1906), a rare and extraordinary Fauve-period picture, was sold for $605,000 to an unidentified collector. There was some debate after the sale over whether a picture by Braque had not sold for a higher amount earlier.

But the star tonight was Picasso, although there were no early sought-after pictures by the artist in the sale -- like the 1901 "Yo Picasso," which brought a record $5.3 million at a previous auction. The Picassos auctioned tonight were:

* "Nature Morte, Te te de Mort, Poireaux et Pot" (1945), for $632,000;

* "Le Peinture et son Mode le," a late 1962 painting of the artist at work at his easel drawing a nude model, for $209,000;

* "Nu Couche'," an even later 1968 abstract reclining nude, which garnered a $220,000 bid;

* "Homme a la Pipe et Fleur," a wildly expressionistic canvas of a man smoking a pipe next to what may be a sunflower, which brought $297,000;

* "Buste d'Homme" (1969), a portait of a man, for $165,000;

"Comptier et Guitare" (1927-29) was the only disappointment tonight. The late Cubist study of a guitar and figure failed to meet the consignor's minimum price.

The sale started at 7 p.m. and continued for nearly two hours. The late artist's daughter Paloma Picasso, as well as Bianca Jagger and some 600 art fanciers, crowded into the main salesroom and two adjacent rooms.

The main excitement of the evening came 25 minutes into the sale when the Annenberg Monet brought several bidders to their feet followed by a round of applause.

"I will tell you something," said de Kwiatkowski, the new owner of the Monet, who had flown in just for the sale after buying $10 million worth of horses in Kentucky. "I am a good friend of Mr. Annenberg's. I just had dinner with him two nights ago in Los Angeles. But I didn't know until tonight that it was his Monet. If I had known, I would have bought it from him after dinner." CAPTION: Picture, Detail from Picasso's "Femme Assise au Chapeau," which sold for $4.3 million. Courtesy of Christie's New York