A coveted cache of modern masters collected since the 1950s by Long Island residents Rudolph and Hannelore Schulhof will go under the gavel this fall.

In November, Christie's will offer 63 pieces from the Schulhof collection, including work by Joan Miro, Ellsworth Kelly and Robert Indiana. The sale could generate $25 million.

Some 100 works from the collection were promised to museums. The couple became friends with Peggy Guggenheim and designated a large portion of art to her museum in Venice. Another 200 artworks will remain in their home for family to distribute later.

Christie's will open the Schulhof mansion to the public this Saturday and Sunday from 10 a.m. to 5 p.m. at 12 Dock Lane in Kings Point, on the North Fork of Long Island, N.Y.