GTI Properties was founded by Mario Nicosia approximately thirty years ago when he opened a real estate brokerage office on Newbury Street in Boston’s Back Bay. As he leased and sold real estate in the Boston market, he began to acquire residential properties in the St. Botolph Street district, renovating the buildings and providing first-class apartments in an emerging city neighborhood. Over the years he acquired a large number of residential properties on this border between the Back Bay and the South End.   In the 1980’s he turned his attention to the old, vacant mill buildings on the eastern edge of the South End. This area, known today as SoWa (South of Washington Street), has become a lively commercial district serving artists, residences and creative businesses.

Today, GTI Properties manages over three hundred residential apartments in the Back Bay and the South End and oversees the leasing and development of over one million square feet of commercial office space in the SoWa District.