Equity Residential (EQR) is a real estate investment trust (REIT). The Company is focused on the acquisition, development and management of apartment properties in United States markets. It is a real estate company and is an owner of multifamily properties in the United States. As of December 31, 2010, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 451 properties located in 17 states and the District of Columbia consisting of 129,604 apartment units. As of December 31, 2010, EQR owned an approximate 95.5% ownership interest in, ERP Operating Limited Partnership. In February 2010, the Company, as part of a three-property transaction in New York City, has acquired two high-rise apartment towers.