WHITE PLAINS, N.Y. — URDANG has disposed of a 320,000-square-foot office building, located at 1311 Mamaroneck Ave. in White Plains, for $81.77 million. Situated on 25 acres, the building includes a full-service cafeteria, a fitness center, a parking garage and concierge services. Tenants at the fully occupied building include Acadia Realty and OrthoNet. Jonathan Davis, John Saraceno, Vincent Sanfilippo and David Spoont of Onyx Equities negotiated the sale on behalf of URDANG. Matthew Keefe of HK Group represented the undisclosed buyer.