AFFILIATED MANAGERS GROUP, INC. — Director's Dealing 2010

Aug 20, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AFFILIATED MANAGERS GROUP INC (AMG)
CIK: 0001004434
Period of Report: 2010-08-19

Reporting Person: DALTON NATHANIEL (Executive V.P. and COO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-08-19	Common Stock	M	14726	$44.35	Acquired	59762	Direct
2010-08-19	Common Stock	S	14726	$68.23	Disposed	59762	Direct
2010-08-20	Common Stock	M	27520	$44.35	Acquired	59762	Direct
2010-08-20	Common Stock	S	27520	$67.63	Disposed	59762	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-08-19	Employee Stock Option (Right to Buy)	$44.35	M	14726	Disposed	2010-12-10	Common Stock (14726)	Direct
2010-08-20	Employee Stock Option (Right to Buy)	$44.35	M	27520	Disposed	2010-12-10	Common Stock (27520)	Direct

Footnotes

F1: The sale price reflects the weighted average sales price of the shares sold; the individual transaction prices ranged from $68.12 to $68.37. Specific transaction details will be provided to the SEC upon request.

F2: The sale price reflects the weighted average sales price of the shares sold; the individual transaction prices ranged from $67.37 to $68.00. Specific transaction details will be provided to the SEC upon request.