SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* HEALEY SEAN M (Last) (First) (Middle) C/O AFFILIATED MANAGERS GROUP, INC. 600 HALE STREET (Street) PRIDES CROSSING MA 01965 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol AFFILIATED MANAGERS GROUP INC [ AMG ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner X Officer (give title below) Other (specify below) President and CEO
	3. Date of Earliest Transaction (Month/Day/Year) 05/02/2005
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/02/2005		M		62,586	A	$23.0867	22,381	D
Common Stock	05/02/2005		M		41,249	A	$18.46	22,381	D
Common Stock	05/02/2005		M		6,753	A	$19.3333	22,381	D
Common Stock	05/02/2005		M		3,129	A	$31.9583	22,381	D
Common Stock	05/02/2005		S		100,000	D	$62.3856	22,381	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	$23.0867	05/02/2005		M			62,586	04/16/2002	04/16/2008	Common Stock	62,586	$23.0867	0	D
Employee Stock Option (Right to Buy)	$18.46	05/02/2005		M			41,249	12/03/2002	12/03/2008	Common Stock	41,249	$18.46	0	D
Employee Stock Option (Right to Buy)	$19.3333	05/02/2005		M			6,753	12/02/2003	12/02/2009	Common Stock	6,753	$19.3333	173,247	D
Employee Stock Option (Right to Buy)	$31.9583	05/02/2005		M			3,129	12/31/2004	12/19/2010	Common Stock	3,129	$31.9583	71,871	D

Explanation of Responses:

	/s/ John Kingston, III, Attorney-in-Fact	05/04/2005
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.