Sotheby's in New York City expects the Emile-Jacques Ruhlmann-designed piece will sell for between $400,000 and $600,000 during an auction of 20th Century design works next month.

The piano was purchased by the Butler family of Buffalo in the early 1940s and for years was displayed in the Butlers' opulent mansion in the city.

Sotheby's says the piano is one of only six Ruhlmann pianos whose whereabouts are known and one of three that are similarly shaped.

"In a sense it's the opposite of what a classic, say Steinway, shape would be. It was Ruhlmann's great modernist style and innovation in the (19)20s that would come up with something like that," said James Zemaitis, the auction house's senior vice president of 20th century design. "Where the piano should go in it goes out on the side. Convex versus concave."

Made from macassar ebony and American walnut and accented with gilt bronze and ivory, Ruhlmann first displayed the style at the landmark 1925 Paris art deco exposition.

"In the main room, Ruhlmann exhibited another example of this piano," Zemaitis said. "That piano immediately became iconic because of its presence in the central room."

Aboard the Normandie, the piano now up for sale occupied the ladies' drawing room and music room, which was decorated with Ruhlmann's furniture in tribute to the French designer, who died in 1933. The Normandie sailed its maiden voyage in May 1935.

After the outbreak of World War II in 1939, the U.S. Navy seized the Normandie while it was docked at Manhattan's West Side piers. The Navy planned to convert it into the troopship, the USS Lafayette, and the piano was sold along with the rest of the ship's contents in a series of auctions.

Before the conversion could be completed, a fire broke out aboard the ship on Feb. 9, 1942. Early the next morning, the ship capsized onto its port side at Pier 88. The vessel was eventually righted, but the conversion operation was deemed too costly, and the ship was sold for scrap after the war.

The Butler family, which founded and, until the 1970s, owned The Buffalo News, purchased the instrument at a New York auction in the early 1940s after having seen and played the piano while sailing aboard the Normandie, according to Sotheby's.

The piano has been passed down to the granddaughter of the original owners, who has declined to be identified.

The auction is scheduled for March 6.