NEW YORK (Reuters) - A portrait of a woman by Amedeo Modigliani sold for $5.4 million on Tuesday, kicking off a two-day auction of 20th century art at Christie`s New York. The Modigliani portrait, "Femme en robe ecossaise," fetched far more than the $3.5 million to $4.5 million price auctioneers had expected. A second work by the Italian painter known for his stylized, elongated portraits, titled "Seated Young Girl," sold for $4.8 million. Also selling in the early evening auction was Georges Braque`s vibrantly colored "L`Olivier pres de l`Estaque," painted in 1906. The work sold for $4.4 million. "Violon et verre," also by Braque, a founder of Cubism, sold for $4.2 million. Among the several works by Pablo Picasso up for auction, "Buste de femme" sold for $3.3 million. Painted in Paris in 1940, the work represents his mistress Dora Maar. Another Picasso, "Femme au chapeau assise," painted in 1971, sold for $2.4 million. Selling for a price above the $1.5 million high estimate was "Ocean Park No. 9" by Richard Diebenkorn, a 1968 abstract landscape owned by The Times Mirror Co. The winning bid was $1.65 million. An untitled piece by Mark Rothko, showing rich green and blue rectangles, sold for $3.6 million. "Homme qui marche III" by Swiss sculptor Alberto Giacometti sold for $3 million. Most of the sales fell within the estimates expected by the auction house. Highlights of the auction`s second day were expected to be two oil paintings by surrealist Salvador Dali.