Five bronzes by Constantin Brancusi, unseen at auction until now, will be sold as a single-owner group in New York on 18 November. Bonhams expects the collection, titled Brancusi: The Legacy, to bring in $25 million when it goes under the hammer at the auction house's flagship galleries at 111 West 57th Street, ahead of its 20th and 21st Century Art Evening Sale later the same day.

The works were bought directly from the artist's estate during the 1980s and 1990s and have stayed in the same private collection ever since. They span the sculptor's defining subjects: the sleeping or disembodied head, the abstracted portrait, the fragmented torso and the animal form, with the pieces first conceived between 1917 and 1937. The bronzes themselves were cast after Brancusi's death by the Susse Foundry between 1973 and 1991, from duplicates of his original plasters, in numbered editions authorised by Alexandre Istrati and Natalia Dumitresco.

Leading the group is Torse de jeune homme, conceived in plaster in 1922 and cast in bronze in 1924, which is offered with its estimate available on request. Also included is La jeune fille sophistiquée, a portrait of Nancy Cunard conceived in 1928, estimated at $3.5 million to $5.5 million. Bonhams describes the chance to present five works of this standing together, fresh to the market, as a rare opportunity for collectors.

The sale arrives in the 150th anniversary year of Brancusi's birth, while a major exhibition of his work is on view at the Museum of Modern Art in New York. It also lands in a season when the sculptor's market has been running hot: his Danaïde sold for $107.6 million at Christie's in May, the second-highest price ever paid for a sculpture at auction.