Salvador Dali's portrait of a New York style icon and Joan Miro's homage to his Catalan roots are going on sale at a London auction of surrealist masterpieces.

Dali's 1943 "Portrait of Mrs. Harrison Williams" will go under the hammer Tuesday with an estimated price of between 1.5 million and 2 million pounds ($2.4 million and $3.2 million).

Dali painted the ultra-rich and super-stylish socialite - who later became Countess Mona Bismarck - barefoot and dressed in black rags.

Proceeds will go to the Mona Bismarck American Center in Paris, which promotes Franco-American cultural relations.

Also for sale is Miro's 1936 "The Farmer and His Wife," a vibrant portrait of human figures and barnyard animals, valued between 5.5 million pounds and 7.5 million pounds ($8.7 million to $11.9 million).

Reporters also were given a preview Thursday of Sotheby's February auctions of Impressionist, modern and contemporary art, including works by Pablo Picasso, Claude Monet, Egon Schiele, Francis Bacon and Jean-Michel Basquiat.