NEW YORK CITY, NY – March 9, 2012 – (RealEstateRama) — Perseus Books Group has consolidated its operations in New York City into a single property: 250 West 57th Street, where it has expanded its occupancy from 6,800 square feet to the entire 15th floor of 26,104 square feet, announces Anthony Malkin, president of Malkin Holdings LLC, which supervises W&H Properties.