Boston, MA... October 27, 2008

State Street Corporation,, (NYSE: STT) announced today that it has entered into a definitive purchase agreement for its participation in the United States Department of the Treasury’s voluntary capital purchase program (CPP). Under the agreement, Treasury will invest $2 billion in State Street and receive 20,000 shares of State Street’s Series B fixed-rate cumulative perpetual preferred stock, $100,000 liquidation preference per share, and a 10-year warrant to purchase 5,576,208 shares of State Street’s common stock at an exercise price of $53.80 per share. The exercise price of the warrant was determined based upon the average of closing prices of State Street’s common stock during the 20-trading day period ended October 10, 2008, the trading day prior to the date State Street agreed to participate in the program. The terms of the investment are consistent with the terms Treasury has made available on its website, www.ustreas.gov, concerning its TARP capital purchase program. The closing of the transaction is expected to occur within the next several days and is subject to customary conditions.

The preferred stock, the warrant and any common stock issuable upon exercise of the warrant, have not been registered under the Securities Act of 1933, as amended, or the securities laws of any other jurisdiction and, may not be offered or sold in the United States absent registration or an applicable exemption from, registration requirements.

This announcement does not constitute an offer to sell or the solicitation of offers to buy these securities, nor shall there be any offer or sale of these securities in any state in which such offer, solicitation or sale would be unlawful.