FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * DALTON NATHANIEL   2. Issuer Name and Ticker or Trading Symbol AFFILIATED MANAGERS GROUP INC [AMG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Executive V.P. and COO (Last) (First) (Middle) C/O AFFILIATED MANAGERS GROUP, INC., 600 HALE STREET 3. Date of Earliest Transaction (Month/Day/Year) 08/06/2007 (Street) PRIDES CROSSING, MA 01965 4. If Amendment, Date 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 (City) (State) (Zip) 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 08/06/2007   A   4,424 (1) A $ 115.45 63,124 D   Common Stock 08/07/2007   M   35,119 A $ 31.96 63,124 D   Common Stock 08/07/2007   M   18,750 A $ 38.73 63,124 D   Common Stock 08/07/2007   S   53,869 D $ 115.76 (2) 63,124 D

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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 Underlying Securities (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 of Derivative Security: 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)

$ 31.96

08/07/2007

M

35,119

12/31/2004

12/19/2010

Common Stock

35,119

$ 31.96

18,000

D

Employee Stock Option (Right to Buy)

$ 38.73

08/07/2007

M

18,750

12/31/2004

07/24/2008

Common Stock

18,750

$ 38.73

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
DALTON NATHANIEL C/O AFFILIATED MANAGERS GROUP, INC. 600 HALE STREET PRIDES CROSSING, MA 01965			Executive V.P. and COO

Signatures

/s/ John Kingston, III, Attorney-in-Fact		08/08/2007
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Under the terms of the Company's 2005 Executive Retention Plan, Mr. Dalton was allocated 4,424 shares, subject to forfeiture, which will vest upon continuing service in 33% increments on each of January 1, 2008, January 1, 2009 and January 1, 2010.
(2)	The reported amount is the average sales price; the individual transaction prices ranged from $115.30 to $116.20.

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