Four paintings, including a Picasso worth several million dollars, have been left to the Chicago Art Institute by the late Mary Block.

The Chicago Sun-Times learned yesterday that the Block estate, part of which is to be auctioned May 20 at Sotheby Parke Bernet in New York, has given the museum Picasso's "Seated Woman," which if sold in the current art market "would surely draw a price of several million dollars," according to a Chicago dealer.

Other Block gifts will include a painting of ballet dancers by Edgar Degas; an oil study by Georges Seurat, made for the most popular of modern paintings in the museum's permanent collection, "A Sunday Afternoon on the Island of La Grand Jatte"; and a Paul Klee known as "Sunset."

Although the Sotheby's auction will offer no works comparable in stature with the Picasso and the Degas, it will feature over 70 outstanding pieces, among them Paul Gauguin's oil "Contes Barbares," Georges Braque's "The Billiard Table" and "Landscape La Ciotat" and a still life by the 17th-century Flemish master Jan Breughel the Elder.

Total value of the sale is expected to be between $6 million and $8 million.