SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 10-Q/A

(MARK ONE)

             [X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
                  FOR THE QUARTERLY PERIOD ENDED JUNE 30, 2000
                                       OR
            [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
               For the transition period from ________ to ________

                        Commission File Number 001-13459

                         AFFILIATED MANAGERS GROUP, INC.
             (Exact name of registrant as specified in its charter)

              DELAWARE                                  04-3218510
  (State or other jurisdiction of           (IRS Employer Identification Number)
   incorporation or organization)

              TWO INTERNATIONAL PLACE, BOSTON, MASSACHUSETTS 02110
                    (Address of principal executive offices)

                                 (617) 747-3300
              (Registrant's telephone number, including area code)

      Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes [X] No [ ]

      Number of shares of the Registrant's Common Stock outstanding at August
10, 2000: 22,116,051 including 266,650 shares of Class B Non-Voting Common
Stock. Unless otherwise specified, the term Common Stock includes both Common
Stock and Class B Non-Voting Common Stock.




                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                AFFILIATED MANAGERS GROUP, INC.
                                (Registrant)



                                                                             
/s/ DARRELL W. CRATE   on behalf of the Registrant as Senior Vice President,       August 21, 2000
- --------------------         Chief Financial Officer and Treasurer
(Darrell W. Crate)           (and also as Principal Financial and
                                 Principal Accounting Officer)