<SEC-DOCUMENT>0001047469-12-006068.txt : 20120515
<SEC-HEADER>0001047469-12-006068.hdr.sgml : 20120515
<ACCEPTANCE-DATETIME>20120515161011
ACCESSION NUMBER:		0001047469-12-006068
CONFORMED SUBMISSION TYPE:	13F-NT
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120331
FILED AS OF DATE:		20120515
DATE AS OF CHANGE:		20120515
EFFECTIVENESS DATE:		20120515

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AFFILIATED MANAGERS GROUP INC
		CENTRAL INDEX KEY:			0001004434
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		IRS NUMBER:				043218510
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		13F-NT
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	028-04975
		FILM NUMBER:		12844732

	BUSINESS ADDRESS:	
		STREET 1:		600 HALE STREET
		STREET 2:		/
		CITY:			PRIDES CROSSING
		STATE:			MA
		ZIP:			01965
		BUSINESS PHONE:		6177473300

	MAIL ADDRESS:	
		STREET 1:		600 HALE STREET
		STREET 2:		/
		CITY:			PRIDES CROSSING
		STATE:			MA
		ZIP:			01965
</SEC-HEADER>
<DOCUMENT>
<TYPE>13F-NT
<SEQUENCE>1
<FILENAME>a2209514z13f-nt.txt
<DESCRIPTION>13F-NT
<TEXT>
<Page>


                                UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549

                                  Form 13F

                             Form 13F COVER PAGE


Report for the Calendar Year or Quarter Ended:  March 31, 2012
                                                ------------------

Check Here if Amendment / /; Amendment Number:
                                               ---------
This Amendment (Check only one.):    / / is a restatement.
                                     / / adds new holdings entries.

Institutional Investment Manager Filing this Report:

   Name:         Affiliated Managers Group, Inc.
                 ------------------------------------
   Address:      600 Hale Street
                 ------------------------------------
                 Prides Crossing, Massachusetts 01965
                 ------------------------------------

                 -------------------------------

Form 13F File Number:       28-04975
                      ---------------------

    The institutional investment manager filing this report and the person by
whom it is signed hereby represent that the person signing the report is
authorized to submit it, that all information contained herein is true,
correct and complete, and that it is understood that all required items,
statements, schedules, lists, and tables, are considered integral parts of
this form.

Person Signing this Report on Behalf of Reporting Manager:

Name:    John Kingston, III
         -------------------------------------------------------
Title:   Vice Chairman, General Counsel and Secretary
         -------------------------------------------------------
Phone:   617-747-3300
         ----------------------------------------------------

Signature, Place, and Date of Signing:

/s/ John Kingston, III      Prides Crossing, Massachusetts   May 15, 2012
-------------------------   ------------------------------   -----------------
[Signature]                 [City, State]                    [Date]

Report Type (Check only one.):

    / / 13F HOLDINGS REPORT. (Check here if all holdings of this reporting
        manager are reported in this report.)

<Page>

    /X/ 13F NOTICE. (Check here if no holdings reported are in this report,
        and all holdings are reported by other reporting manager(s).)

    / / 13F COMBINATION REPORT. (Check here if a portion of the holdings for
        this reporting manager are reported in this report and a portion are
        reported by other reporting manager(s).)

   List of Other Managers Reporting for this Manager:

Form 13F File     Name
Number

<Table>
----------------------------------------------------------------
<S>               <C>
28-12347          Aston Asset Management, LP
----------------------------------------------------------------
28-05835          Chicago Equity Partners, LLC
----------------------------------------------------------------
28-00878          Essex Investment Management Company, LLC
----------------------------------------------------------------
28-05582          First Quadrant, L.P.
----------------------------------------------------------------
28-11858          Foyston, Gordon & Payne Inc.
----------------------------------------------------------------
28-01346          Friess Associates, LLC
----------------------------------------------------------------
28-01185          Frontier Capital Management Company, LLC
----------------------------------------------------------------
28-04145          Gannett Welsh & Kotler, LLC
----------------------------------------------------------------
28-10957          Genesis Asset Managers, LLP
----------------------------------------------------------------
28-10955          Genesis Investment Management, LLP
----------------------------------------------------------------
28-04434          Harding Loevner LP
----------------------------------------------------------------
28-04534          J.M. Hartwell Limited Partnership
----------------------------------------------------------------
28-04884          The Renaissance Group LLC
----------------------------------------------------------------
28-05015          Systematic Financial Management, L.P.
----------------------------------------------------------------
28-11289          Third Avenue Management LLC
----------------------------------------------------------------
28-11092          TimesSquare Capital Management, LLC
----------------------------------------------------------------
28-10163          Trilogy Global Advisors, LP
----------------------------------------------------------------
28-01222          Tweedy, Browne Company LLC
----------------------------------------------------------------
28-00262          Welch & Forbes LLC
----------------------------------------------------------------
</Table>



</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
