Vornado Realty Trust, a real estate investment trust (REIT), is the owner and manager of the commercial real estate in the United States, with a portfolio concentrated in the New York City, Chicago and San Francisco. The company has partnership with Alexander's, Inc. In New York, the company also owns signage throughout the Penn District and Times Square as well as Building Maintenance Services LLC, a wholly owned subsidiary, that provides cleaning and security services for Vornado's buildings and third parties. In addition, Vornado has the MART in Chicago and more than 500 California Street property in San Francisco. The company owns and manages more than 26 million square feet of Leadership in Energy and Environmental Design (LEED) certified buildings. Vornado completed the development phase of a residential condominium tower, 220 Central Park South.