An Italian property group is in advanced talks to take the largest stake in the Flatiron Building, one of the oldest and most distinctive skyscrapers in New York.

A deal could pave the way for a radical redevelopment of the building, famous from the early 20th century for its narrow triangular shape and location at the intersection of two of Manhattan’s most important roads, from its current use as peculiarly-shaped offices for the publisher Macmillan to a luxury hotel.