AMG Commences Tender Offer for 6% Senior Notes Component of 2001 PRIDES.

BOSTON -- Affiliated Managers Group, Inc. (NYSE: AMG) announced that it has commenced a cash tender offer to purchase up to $230,000,000 principal amount of its outstanding 6% Senior Notes due November 17, 2006. The notes were originally issued on December 21, 2001 by AMG in connection with its 2001 PRIDES, which consisted of a purchase contract for a specified number of shares of AMG common stock, collateralized by the related note. The purchase contracts will not be affected by the tender offer.

"Upon the completion of this tender offer, our 2001 PRIDES will effectively be replaced by our 2004 PRIDES," stated Darrell W. Crate, Executive Vice President and Chief Financial Officer. "These 2004 financing transactions extend the maturity of our obligations, and ensure that we have ample capacity to continue to make accretive new investments."

For each $1,000 principal amount of notes validly tendered, AMG is offering to pay an amount in cash equal to the sum of (1) a fixed cash payment of $21.25 and (2) the price of a zero-coupon U.S. Treasury security in a principal amount at maturity of $1,000 and with a maturity date of November 15, 2004, as determined on the second business day prior to the expiration date. All holders of notes who are holders of record on August 2, 2004, including those who tender their notes in the offer, will be entitled to receive the regular coupon payment, which is scheduled to be paid on August 17, 2004. The tender offer is expected to expire at 5:00 p.m., New York City time, on Monday, August 2, 2004, unless extended or earlier terminated. The settlement date will be promptly after the expiration date, which is expected to be August 5, 2004. These and other terms of the tender offer are described in an Offer to Purchase and related Letter of Transmittal provided to the holders of the notes.

The fixed cash payment will be paid directly to the tendering holders of notes. By tendering their notes, the holders will direct the Depositary Agent for the tender offer to use that portion of the consideration related to the Treasury securities to purchase the Treasury securities which are required to be substituted as collateral under the pledge arrangement as security for the tendering holders' obligations under the purchase contracts. If so directed, the Depositary Agent has agreed to purchase or otherwise deliver the Treasury securities on behalf of the holders in order to facilitate their ability to tender the notes pursuant to the tender offer.

For the tender offer, Merrill Lynch & Co. will serve as the Dealer Manager and D.F. King & Co., Inc. will serve as the Information Agent. Requests for information should be directed to Merrill Lynch & Co. at [phone] (toll free) or [phone], and requests for documentation should be directed to D.F. King & Co., Inc. at [phone] (toll free) or [phone] (banks and brokers). The Depositary Agent is The Bank of New York.

THIS ANNOUNCEMENT IS NOT AN OFFER TO PURCHASE OR A SOLICITATION OF AN OFFER TO SELL WITH RESPECT TO THE NOTES. THE OFFER IS BEING MADE SOLELY BY THE OFFER TO PURCHASE AND THE RELATED LETTER OF TRANSMITTAL.

AMG is an asset management company with equity investments in a diverse group of mid-sized investment management firms. Including AMG's recent investment in Genesis Asset Managers, the Company's affiliated investment management firms managed over $100 billion in assets at March 31, 2004.

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 failure to satisfy the conditions to the tender offer set forth in the Offer to Purchase and AMG's ability to otherwise complete the tender offer, 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 close pending investments, the investment performance of AMG's Affiliates and their ability to effectively market 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 AMG'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.