This excerpt taken from the EQR 10-K filed Feb 28, 2007.
During the year ended December 31, 2006, the Company repurchased 1,897,912 of its Common Shares on the open market at an average price of $43.85 per share. The Company paid approximately $83.2 million for these shares, which were retired subsequent to the repurchase.
The equity positions of various individuals and entities that contributed their properties to the Operating Partnership in exchange for OP Units are collectively referred to as the Minority Interests Operating Partnership. Subject to certain restrictions, the Minority Interests Operating Partnership may exchange their OP Units for EQR Common Shares on a one-for-one basis.