AMG Names Robert Puff to its Board of Directors.

Business Editors

BOSTON--(BUSINESS WIRE)--April 21, 2004

Affiliated Managers Group, Inc. (NYSE: AMG), an asset management holding company, announced today the election of Mr. Robert C. Puff, Jr. to its Board of Directors.

Mr. Puff served as President and Chief Investment Officer of American Century Investment Management, Inc., an investment management firm based in Kansas City, Missouri. Since joining American Century Investments in 1983, Mr. Puff has also served on the company's executive committee and board of directors, and currently serves as a senior adviser. Founded in 1958, American Century Investments manages over $90 billion of client assets. Mr. Puff also serves as a director of Sands Capital Management, Inc., a Virginia-based investment manager. Mr. Puff earned a Bachelor's degree from Bucknell University and a Master's degree in finance from the Wharton School at the University of Pennsylvania. He is a chartered financial analyst.

"We are very pleased to welcome Bob to our Board," said William J. Nutt, Chairman and Chief Executive Officer of AMG. "With his many years of experience in the asset management industry and his diverse background, he brings management and industry expertise that will further strengthen our distinguished Board."

AMG is an asset management company that acquires and holds majority equity investments in a diverse group of mid-sized investment management firms. Pro forma for its pending investment in Genesis Asset Managers, AMG's affiliated investment management firms managed approximately $100 billion in assets as of December 31, 2003.

Certain matters discussed in this press release may constitute forward-looking statements within the meaning of the federal securities laws. Actual results and the timing of certain events could differ materially from those projected in or contemplated by the forward-looking statements due to a number of factors, including changes in the securities or financial markets or in general economic conditions, the availability of equity and debt financing, competition for acquisitions of interests in investment management firms, the ability to complete pending acquisitions, the investment performance of our Affiliates and their ability to market effectively their investment strategies, and other risks detailed from time to time in AMG's filings with the Securities and Exchange Commission. Reference is hereby made to the "Cautionary Statements" set forth in the Company's Form 10-K for the year ended December 31, 2003.

For more information on Affiliated Managers Group, Inc., please visit AMG's Web site at www.amg.com.