STT State Street Corporation

State Street Corporation (NYSE:STT), the world�s leading provider of financial services to institutional investors, announced today the results of the State Street Private Equity Indexsm as of March 31, 2008. The index is based on the latest quarterly statistics from State Street Investment Analytics� Private Edge� Group. The Private Edge� Group provides detailed analyses of private equity investments for a diverse client base including public and private pensions, endowments and foundations, representing more than 4,000 commitments totaling more than $200 billion. The Private Edge� Group has one of the most extensive and comprehensive private equity data sets currently maintained in the marketplace, including partnership information down to the portfolio company level. State Street Investment Analytics provides performance and analytics services through 14 offices located around the world. It provides services for more than 1,200 clients globally on asset volumes exceeding $5.5 trillion in assets. The following tables (see accompanying multimedia) depict the quarter-over-quarter internal rates of return (IRR) of the index, the end-to-end IRRs for the index across 1-, 3-, 5- and 10-year horizons as of March 31, 2008, and the long-term internal rates of return (IRR) of the index by major private equity strategy, in addition to the composition of the index. State Street Private Equity Indexsm Composition and long-term IRR as of March 31, 2008 � � � Strategy � Number of Funds � Commitments ($B) � Long-term IRR% Buyout � 639 � 885.9 � 15.4 Venture Capital � 607 � 202.7 � 12.9 Other � 170 � 149.2 � 12.8 Total � 1,416 � 1,237.8 � 14.8 US only � 1,168 � 961.2 � 13.9 International only � 248 � 276.6 � 20.6 �While private equity wasn�t immune to the turbulence in the financial market in the first quarter of 2008,� said Gerard J. Labonte, vice president, State Street Corporation, �swings in private equity valuations are tempered by the focus on long-term management of underlying investments instead of reaction to quarterly earnings announcements. Overall, residual value multiples for the Index actually remained fairly stable from the prior quarter.� Commenting on the prospects for new launches in the current economic landscape, Labonte noted, �We�ve noticed that funds launched in 2003, the year of the most recent (public) market bottom, have performed quite well in comparison to their peers. If recent history is any indication, funds launched in turbulent times can obtain pricing advantages to generate significant long-term returns.� About State Street Investment Analytics State Street Investment Analytics (SSIA) provides private equity performance and analytics services through The Private Edge� Group, which it has offered for more than a decade. The Private Edge� Group provides detailed analyses of customers� private equity portfolios through a fully automated web-enabled environment and offers services ranging from performance measurement to complex quantitative and qualitative portfolio analysis. SSIA provides client services from 14 offices around the world, including Alameda, Amsterdam, Boston, Dublin, Edinburgh, Frankfurt, Hong Kong, London, Luxembourg, New York, Paris, Sydney, Toronto and Zurich. About State Street State Street Corporation (NYSE: STT) is the world's leading provider of financial services to institutional investors, including investment servicing, investment management and investment research and trading. With $15.3 trillion in assets under custody and $1.9 trillion in assets under management at June 30, 2008, State Street operates in 26 countries and more than 100 geographic markets worldwide. For more information, visit State Street�s website at www.statestreet.com.