Affiliated Managers Group, Inc.
(Exact name of registrant as specified in its charter)

600 Hale Street, Prides Crossing, Massachusetts 01965
(Address of principal executive offices)

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 ý No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ý No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No ý

There were 52,053,190 shares of the registrant's common stock outstanding on May 5, 2011.

AFFILIATED MANAGERS GROUP, INC.

CONSOLIDATED STATEMENTS OF INCOME

(in millions, except per share data)

(unaudited)

		For the Three Months Ended March 31,

		2010			2011
Revenue		$	251.0		$	426.3
Operating expenses:
	Compensation and related expenses		119.2			179.5
	Selling, general and administrative		45.3			87.5
	Amortization of intangible assets		8.9			22.1
	Depreciation and other amortization		3.0			3.8
	Other operating expenses		6.1			8.5

			182.5			301.4

Operating income			68.5			124.9

Non-operating (income) and expenses:
	Investment and other income		(2.8	)		(8.7	)
	Income from equity method investments		(9.1	)		(10.2	)
	Investment income from investments in partnerships		(4.1	)		—
	Interest expense		16.0			19.4
	Imputed interest expense		3.8			8.3

			3.8			8.8

Income before income taxes			64.7			116.1
Income taxes			11.9			26.7

Net income			52.8			89.4
Net income (non-controlling interests)			(31.3	)		(50.3	)
Net income (non-controlling interests in partnerships)			(4.0	)		—

Net Income (controlling interest)		$	17.5		$	39.1

Average shares outstanding—basic			42.4			51.8
Average shares outstanding—diluted			45.4			53.1
Earnings per share—basic		$	0.41		$	0.76
Earnings per share—diluted		$	0.38		$	0.74
Supplemental disclosure of total comprehensive income:
Net income		$	52.8		$	89.4
Other comprehensive income			25.4			11.4

Comprehensive income			78.2			100.8
Comprehensive income (non-controlling interests)			(35.3	)		(50.3	)

Comprehensive income (controlling interest)		$	42.9		$	50.5

The accompanying notes are an integral part of the Consolidated Financial Statements.

AFFILIATED MANAGERS GROUP, INC.

CONSOLIDATED BALANCE SHEETS

(in millions)

(unaudited)

			December 31, 2010			March 31, 2011

Assets
Current assets:
	Cash and cash equivalents		$	313.3		$	252.8
	Investment advisory fees receivable			236.4			231.2
	Investments in marketable securities			116.0			110.3
	Unsettled fund share receivables			42.0			103.8
	Prepaid expenses and other current assets			61.7			83.5

		Total current assets		769.4			781.6
Fixed assets, net				67.7			66.0
Equity investments in Affiliates				678.9			622.7
Acquired client relationships, net				1,424.2			1,409.6
Goodwill				2,131.2			2,142.6
Other assets				219.8			236.8

		Total assets	$	5,291.2		$	5,259.3

Liabilities and Equity
Current liabilities:
	Accounts payable and accrued liabilities		$	252.8		$	207.3
	Unsettled fund share payables			39.8			95.3
	Payables to related party			114.8			80.5

		Total current liabilities		407.4			383.1
Senior debt				460.0			340.0
Senior convertible securities				422.1			425.5
Junior convertible trust preferred securities				509.9			510.5
Deferred income taxes				495.4			502.9
Other long-term liabilities				207.8			215.0

		Total liabilities		2,502.6			2,377.0
Redeemable non-controlling interests				406.3			531.2
Equity:
	Common stock			0.5			0.5
	Additional paid-in capital			980.5			854.6
	Accumulated other comprehensive income			100.5			111.9
	Retained earnings			1,011.8			1,050.9

				2,093.3			2,017.9
	Less: treasury stock, at cost			(293.3	)		(256.7	)

		Total equity		1,800.0			1,761.2
	Non-controlling interests			582.3			589.9

	Total equity			2,382.3			2,351.1

	Total liabilities and equity		$	5,291.2		$	5,259.3

The accompanying notes are an integral part of the Consolidated Financial Statements.

AFFILIATED MANAGERS GROUP, INC.

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY

(in millions)

(unaudited)

	Total Stockholders' Equity

	Common Stock		Additional Paid-In Capital			Accumulated Other Comprehensive Income (Loss)		Retained Earnings		Treasury Shares at Cost			Non- controlling interests			Total Equity
December 31, 2010	$	0.5	$	980.5		$	100.5	$	1,011.8	$	(293.3	)	$	582.3		$	2,382.3
Stock issued under option and other incentive plans		—		(21.5	)		—		—		36.6			—			15.1
Tax benefit of option exercises		—		5.7			—		—		—			—			5.7
Changes in Affiliate equity		—		(117.6	)		—		—		—			26.8			(90.8	)
Share-based payment arrangements		—		7.5			—		—		—			—			7.5
Distributions to non-controlling interests		—		—			—		—		—			(69.5	)		(69.5	)
Net Income		—		—			—		39.1		—			50.3			89.4
Other comprehensive income		—		—			11.4		—		—			—			11.4

March 31, 2011	$	0.5	$	854.6		$	111.9	$	1,050.9	$	(256.7	)	$	589.9		$	2,351.1

The accompanying notes are an integral part of the Consolidated Financial Statements.

AFFILIATED MANAGERS GROUP, INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(in millions)

(unaudited)

			For the Three Months Ended March 31,

			2010			2011
Cash flow from operating activities:
	Net income		$	52.8		$	89.4
Adjustments to reconcile Net income to net cash flow from operating activities:
	Amortization of intangible assets			8.9			22.1
	Amortization of issuance costs			1.8			2.6
	Depreciation and other amortization			3.0			3.8
	Deferred income tax provision			8.6			9.6
	Imputed interest expense			3.8			8.3
	Income from equity method investments, net of amortization			(9.1	)		(10.2	)
	Distributions received from equity method investments			23.2			64.9
	Tax benefit from exercise of stock options			0.3			0.8
	Stock option expense			3.6			6.1
	Affiliate equity expense			3.4			3.5
	Other adjustments			(4.0	)		(5.6	)
Changes in assets and liabilities:
	(Increase) decrease in investment advisory fees receivable			(0.9	)		3.0
	(Increase) decrease in prepaids and other current assets			11.0			(2.5	)
	Increase in unsettled fund shares receivable			(98.7	)		(60.7	)
	Increase in other assets			(11.1	)		(2.9	)
	Decrease in accounts payable, accrued liabilities and other long-term liabilities			(37.0	)		(56.5	)
	Increase in unsettled fund shares payable			108.4			54.5

		Cash flow from operating activities		68.0			130.2

Cash flow used in investing activities:
	Investments in Affiliates			(127.7	)		(13.3	)
	Purchase of fixed assets			(1.1	)		(1.7	)
	Purchase of investment securities			(14.9	)		(9.1	)
	Sale of investment securities			11.8			12.0

		Cash flow used in investing activities		(131.9	)		(12.1	)

Cash flow from (used in) financing activities:
	Borrowings of senior bank debt			235.0			—
	Repayments of senior bank debt			(65.0	)		(120.0	)
	Issuance of common stock			2.5			15.2
	Issuance costs			(0.1	)		(7.7	)
	Excess tax benefit from exercise of stock options			0.4			4.9
	Settlement of treasury lock			—			4.0
	Note payments			(25.4	)		0.1
	Distributions to non-controlling interests			(37.2	)		(69.5	)
	Affiliate equity issuances and repurchases			(102.6	)		(7.8	)

		Cash flow from (used in) financing activities		7.6			(180.8	)

Effect of foreign exchange rate changes on cash and cash equivalents				0.6			2.2
Net decrease in cash and cash equivalents				(55.7	)		(60.5	)
Cash and cash equivalents at beginning of period				259.5			313.3

Cash and cash equivalents at end of period			$	203.8		$	252.8

Supplemental disclosure of non-cash activities:
	Notes received for Affiliate equity sales		$	5.7		$	9.5
	Payables recorded for Affiliate equity purchases			15.3			7.0
	Payables recorded under contingent payment arrangements			49.0			—

The accompanying notes are an integral part of the Consolidated Financial Statements.

The consolidated financial statements of Affiliated Managers Group, Inc. ("AMG" or the "Company") have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all of the disclosures required by accounting principles generally accepted in the United States of America. In the opinion of management, all adjustments considered necessary for a fair statement of the results have been included. All intercompany balances and transactions have been eliminated. Certain reclassifications have been made to the prior period's financial statements to conform to the current period's presentation. Operating results for interim periods are not necessarily indicative of the results that may be expected for any other period or for the full year. The Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2010 includes additional information about AMG, its operations, financial position and accounting policies, and should be read in conjunction with this Quarterly Report on Form 10-Q.

All dollar and share amounts in these notes (except information that is presented on a per share, per security, per note or per contract basis) are stated in millions, unless otherwise indicated.

There are no recently issued accounting standards that are expected to have a material effect on the Company's Consolidated Financial Statements.

The Company entered into an amended and restated revolving credit facility (the "credit facility") in January 2011, which allows for borrowings of up to $750.0 million at specified rates of interest that vary depending on the Company's credit ratings. Subject to the agreement of the lenders to provide incremental commitments and subject to certain requirements in the credit facility, the Company has the option to increase the credit facility by up to an additional $150.0 million.

The credit facility, which will mature in January 2015, is unsecured and contains financial covenants with respect to leverage and interest coverage and also contains customary affirmative and negative covenants, including limitations on indebtedness, liens, cash dividends, asset dispositions and fundamental corporate changes. Obligations under the credit facility are guaranteed by certain of the Company's wholly-owned domestic subsidiaries in accordance with the terms of the credit facility. At March 31, 2011, the Company had $340.0 million of outstanding borrowings.

As further described in Note 15, the Company has entered into interest rate swap contracts to exchange a fixed rate for the variable rate on a portion of its credit facility.

At March 31, 2011, the Company has one senior convertible security outstanding ("2008 senior convertible notes") and two junior convertible trust preferred securities outstanding, issued in 2006 (the

"2006 junior convertible trust preferred securities") and in 2007 (the "2007 junior convertible trust preferred securities"). The carrying values of the Company's convertible securities are as follows:

	2008 Senior Convertible Notes⁽¹⁾			2007 Junior Convertible Trust Preferred Securities⁽²⁾			2006 Junior Convertible Trust Preferred Securities⁽³⁾

Issue Date		August 2008			October 2007			April 2006
Maturity Date		August 2038			October 2037			April 2036
Next Potential Put Date		August 2013			N/A			N/A
Note Denomination	$	1,000		$	50		$	50
Current Conversion Rate		7.959			0.250			0.333
Current Conversion Price	$	125.65		$	200.00		$	150.00
Stated Coupon		3.95	%		5.15	%		5.10	%
Coupon Frequency		Semi-annually			Quarterly			Quarterly
Tax Deduction Rate⁽⁴⁾		9.38	%		8.00	%		7.50	%

During 2009, the Company entered into a forward equity sale agreement with a major securities firm to sell shares of its common stock, and extended this agreement in April 2011. As of March 31, 2011, no forward equity sales are outstanding. The Company may sell up to an additional $103.5 million under this agreement.

The consolidated income tax provision includes taxes attributable to controlling interests and, to a lesser extent, taxes attributable to non-controlling interests as follows:

			For the Three Months Ended March 31,

			2010			2011
Controlling Interests:
	Current Tax		$	2.5		$	13.5
	Intangible related deferred taxes			10.7			12.9
	Other Deferred Taxes			(2.1	)		(2.8	)

		Total Controlling Interests	$	11.1		$	23.6

Non-Controlling Interests:
	Current Tax		$	0.8		$	3.6
	Deferred Taxes			—			(0.5	)

		Total Non-Controlling Interests		0.8			3.1

Provision for income taxes			$	11.9		$	26.7

Income before income taxes (controlling interest)			$	28.6		$	62.7

Effective Tax rate attributable to controlling interests⁽¹⁾				38.8	%		37.6	%

		December 31, 2010			March 31, 2011

Deferred Tax Assets
	State net operating loss carryforwards	$	30.6		$	29.6
	Foreign tax credit carryforwards		17.3			19.1
	Deferred compensation		10.3			11.7
	Accrued expenses		8.5			10.3
	Capital loss carryforwards		1.5			1.5

Total deferred tax assets			68.2			72.2
Valuation allowance			(27.6	)		(26.7	)

Deferred tax assets, net of valuation allowance		$	40.6		$	45.5

Deferred Tax Liabilities
	Intangible asset amortization	$	(209.3	)	$	(218.9	)
	Convertible securities interest		(154.5	)		(158.5	)
	Non-deductible intangible amortization		(143.1	)		(143.5	)
	Deferred revenue		(26.3	)		(24.8	)
	Other		(2.8	)		(2.7	)

Total deferred tax liabilities			(536.0	)		(548.4	)

	Net deferred tax liability	$	(495.4	)	$	(502.9	)

Deferred tax liabilities are primarily the result of tax deductions for the Company's intangible assets and convertible securities. The Company amortizes most of its intangible assets for tax purposes only, reducing its tax basis below its carrying value for financial statement purposes and generating deferred taxes each reporting period. The Company's 2008 senior convertible notes and junior convertible trust preferred securities also generate deferred taxes because the Company's tax deductions are higher than the interest expense recorded for financial statement purposes.

At March 31, 2011, the Company has state net operating loss carryforwards that expire over a 15-year period beginning in 2011. The Company also has foreign tax credit carryforwards that expire over a 10-year period beginning in 2011. The valuation allowances at December 31, 2010 and March 31, 2011 were principally related to the Company's ability to generate sufficient taxable income prior to the expiration of these carryforwards.

At March 31, 2011, the Company's liability for uncertain tax positions was $24.6 million, including interest and related charges of $3.0 million. Over the next twelve months, as a result of state and foreign tax audits, unrecognized tax benefits on uncertain tax positions could increase by $1.0 to $3.0 million.

The calculation of basic earnings per share is based on the weighted average number of shares of the Company's common stock outstanding during the period. Diluted earnings per share is similar to basic earnings per share, but adjusts for the dilutive effect of the potential issuance of incremental shares of the Company's common stock. The following is a reconciliation of the numerator and denominator used in the calculation of basic and diluted earnings per share available to common stockholders.

		For the Three Months Ended March 31,

		2010		2011
Numerator:
Net Income (controlling interest)		$	17.5	$	39.1
Interest expense on convertible securities, net of taxes			0.0		—

Net Income (controlling interest), as adjusted		$	17.5	$	39.1

Denominator:
Average shares outstanding—basic			42.4		51.8
Effect of dilutive instruments:
	Stock options		0.9		1.3
	Forward sale		1.3		—
	Senior convertible securities		0.8		—

Average shares outstanding—diluted			45.4		53.1

As more fully discussed in Note 3, the Company had convertible securities outstanding during the periods presented and is required to apply the if-converted method to these securities in its calculation of diluted earnings per share. Under the if-converted method, shares that are issuable upon conversion are deemed outstanding, regardless of whether the securities are contractually convertible into the Company's common stock at that time. For this calculation, the interest expense (net of tax) attributable to these dilutive securities is added back to Net Income (controlling interest), reflecting the assumption that the securities have been converted. Issuable shares for these securities and related interest expense are excluded from the calculation if an assumed conversion would be anti-dilutive to diluted earnings per share.

The calculation of diluted earnings per share for the three months ended March 31, 2010 and 2011 excludes the potential exercise of options to purchase 1.3 million and 0.6 million shares of common stock, respectively, because the effect would be anti-dilutive.

As discussed further in Note 18, the Company may settle portions of its Affiliate equity purchases in shares of its common stock. Because it is the Company's intent to settle these potential repurchases in cash, the calculation of diluted earnings per share excludes any potential dilutive effect from possible share settlements.

The Company and its Affiliates are subject to claims, legal proceedings and other contingencies in the ordinary course of their business activities. Each of these matters is subject to various uncertainties, and it is possible that some of these matters may be resolved in a manner unfavorable to the Company or its Affiliates. The Company and its Affiliates establish accruals for matters for which the outcome is probable and can be reasonably estimated. Management believes that any liability in excess of these accruals upon the ultimate resolution of these matters will not have a material adverse effect on the consolidated financial statements of operations of the Company.

Certain Affiliates operate under regulatory authorities which require that they maintain minimum financial or capital requirements. Management is not aware of any material violations of such financial requirements.

In connection with its investment in Pantheon Ventures, the Company has committed to co-invest in certain investment partnerships where it serves as the general partner. As of March 31, 2011, these commitments totaled approximately $98.6 million and may be called in future periods. Russell Investments (Pantheon Ventures former owner) is contractually obligated to reimburse the Company for $69.6 million of these commitments when they are called.

Under past acquisition agreements, the Company is contingently liable, upon achievement of specified financial targets, to make payments of up to $496.5 million through 2015. In 2011, the Company expects to make payments of approximately $1.4 million to settle portions of these contingent obligations.

As of December 31, 2010 and March 31, 2011, the Affiliates' investments in partnerships that are not consolidated were $106.1 million and $121.9 million, respectively. These assets are reported within "Other assets" in the Consolidated Balance Sheets. The income or loss related to these investments is classified within "Investment and other income" in the Consolidated Statements of Income.

Investments in marketable securities are comprised of the Company's 2009 and 2010 investments in Value Partners Group Limited, a publicly-traded asset management firm based in Hong Kong, and investments held by Affiliates. These investments are carried at their fair value. Changes in fair value for securities classified as available-for-sale are reported in accumulated other comprehensive income. Changes in fair value for trading securities are reported within other operating expenses. The cost of investments in marketable securities, gross unrealized gains and losses were as follows:

Unsettled fund share receivables and payables are created by the normal settlement periods on transactions initiated by certain clients of Affiliate funds domiciled in the United Kingdom. The gross presentation of the receivable and offsetting payable reflects the legal relationship between the underlying investor and the Company.

The Company determines the fair value of certain investment securities and other financial and nonfinancial assets and liabilities. Fair value is determined based on the price that would be received for an asset or paid to transfer a liability in the most advantageous market, utilizing a hierarchy of three different valuation techniques:

The following table summarizes the Company's assets and liabilities that are measured at fair value on a recurring basis:

					Fair Value Measurements

			December 31, 2010		Fair Value Measurements
			December 31, 2010		Level 1		Level 2		Level 3
Financial Assets
	Cash equivalents		$	36.0	$	36.0	$	—	$	—
	Partnership investments⁽¹⁾			124.5		16.9		21.8		85.8
	Investments in marketable securities⁽²⁾
		Trading securities		15.4		15.2		0.2		—
		Available for sale securities		100.6		99.2		1.4		—
	Interest rate derivatives			5.9		—		5.9		—
Financial Liabilities
	Contingent payment obligations⁽³⁾		$	84.0	$	—	$	—	$	84.0
	Obligations to related parties			79.6		—		—		79.6

			March 31, 2011		Level 1		Level 2		Level 3

Financial Assets
	Cash equivalents		$	14.6	$	14.6	$	—	$	—
	Partnership investments⁽¹⁾			152.8		27.9		31.3		93.6
	Investments in marketable securities⁽²⁾
		Trading securities		16.0		16.0		—		—
		Available for sale securities		94.3		94.3		—		—
	Interest rate derivatives			3.0		—		3.0		—
Financial Liabilities
	Contingent payment obligations⁽³⁾		$	89.4	$	—	$	—	$	89.4
	Obligations to related parties			67.9		—		—		67.9

The following is a description of the significant assets and liabilities measured at fair value and the fair value methodologies used.

Cash equivalents consist primarily of highly liquid investments in money market funds. Cash investments in actively traded money market funds are classified as Level 1.

Partnership investments consist of investments in funds advised by Affiliates and are valued using net asset value ("NAV"). Investments in actively traded funds that calculate daily NAVs are classified as Level 1. Investments in non-public funds that hold investments with observable market prices are classified as Level 2. Investments in funds that hold illiquid securities or that are subject to redemption restrictions are classified as Level 3. The fair value of Level 3 assets was determined using NAV one quarter in arrears (adjusted for current period calls and distributions).

Investments in marketable securities consist primarily of investments in funds advised by Affiliates which are valued using NAV and in publicly traded securities. Investments in actively traded funds that calculate daily NAVs and actively traded public securities are classified as Level 1. Investments in non-public funds that hold investments with observable market prices are classified as Level 2.

Interest rate derivatives include Treasury rate lock contracts and interest rate swaps at December 31, 2010 and only interest rate swaps at March 31, 2011. The fair value of these assets was determined by model-derived valuations in which all significant inputs were observable in active markets.

Contingent payment obligations represents the present value of the expected future settlement of contingent payment arrangements related to the Company's business combinations. The fair value of these obligations is determined using an income approach with assumptions made about future cash flows and discount rates.

Obligations to related parties include agreements to repurchase Affiliate equity and liabilities offsetting certain investments which are held by the Company but economically attributable to a related party. The fair value of the agreements to repurchase Affiliate equity is determined using an income approach with assumptions made about future cash flows and discount rates. The liability to a related

party is measured based upon certain investments held by the Company, the fair value of which is determined using NAV.

The following table presents the changes in Level 3 assets and liabilities for the three months ended March 31, 2010 and 2011:

During the three months ended March 31, 2010, financial assets valued at $3.7 million transferred from Level 3 to Level 2. No such transfers occurred during the three months ended March 31, 2011. In addition, there were no significant transfers of financial assets or liabilities between Level 2 and Level 1 in either period.

As a practical expedient, the Company relies on the NAV of certain investments as their fair value. The NAVs that have been provided by the investees have been derived from the fair values of the underlying investments as of the measurement dates. The following table summarizes, as of December 31, 2010 and March 31, 2011, the nature of these investments and any related liquidation restrictions or other factors which may impact the ultimate value realized:

The carrying amount of the Company's cash, cash equivalents and short-term investments approximates fair value because of the short-term nature of these instruments. The carrying value of notes receivable approximates fair value because interest rates and other terms of the notes are at market rates. The carrying value of notes payable approximates fair value principally because of the short-term nature of the notes. The carrying value of senior bank debt approximates fair value because the debt is a credit facility with variable interest based on selected short-term rates. The fair market value of the 2008 senior convertible notes and the junior convertible trust preferred securities at March 31, 2011 was $542.8 million and $664.0 million, respectively.

The Company's Affiliates act as the investment manager for certain investment funds that are considered variable interest entities ("VIEs"). In addition to an Affiliate's involvement as the investment manager, Affiliates may also hold investments in these products. Affiliates are not the primary beneficiary of these VIEs as their involvement is limited to that of a service provider and their investment, if any, represents an insignificant interest in the fund's assets under management. As a result, the Company's variable interests will not absorb the majority of the variability of the entity's net assets and therefore the Company has not consolidated these entities.

The Company established wholly-owned trusts in connection with the 2006 and 2007 issuances of junior convertible trust preferred securities. These entities are considered VIEs and the Company is not the primary beneficiary, therefore these entities are not consolidated in the Company's financial statements.

The net assets and liabilities of these unconsolidated VIEs and the Company's maximum risk of loss related thereto are as follows:

The Company periodically records amounts receivable and payable to Affiliate partners in connection with the transfer of Affiliate equity interests. The Company also has liabilities to related parties for deferred purchase price and contingent payment obligations in connection with certain business combinations.

The total receivable as of December 31, 2010 was $42.9 million, which is included in "Other assets." The total receivable as of March 31, 2011 was $57.0 million, of which $14.3 million is included

in "Prepaid expenses and other current assets" and $42.7 million is included in "Other assets." The total payable as of December 31, 2010 was $183.0 million, of which $114.8 million is included in "Payables to related party" and $68.2 million is included in "Other long-term liabilities." The total payable as of March 31, 2011 was $147.6 million, of which $80.5 million is included in "Payables to related party" and $67.1 million is included in "Other long-term liabilities."

In certain cases, Affiliate management owners and Company officers may serve as trustees or directors of certain mutual funds from which the Affiliate earns advisory fee revenue.

The following summarizes the transactions of the Company's stock option and incentive plans for the three months ended March 31, 2011:

The Company's Net Income (controlling interest) for the three months ended March 31, 2011 includes compensation expense of $3.8 million (net of income tax benefits of $2.3 million related to the Company's Stock Option and Incentive, Long-Term Executive Incentive, Long-Term Equity Incentive and Deferred Compensation Plans). As of March 31, 2011, the Company expects to recognize compensation expense related to these share-based compensation arrangements of $69.7 million over a weighted average period of approximately three years (assuming no forfeitures). As of March 31, 2011, no outstanding options have expiration dates prior to the end of 2011.

The Company periodically uses derivative contracts to manage interest rate exposure associated with its variable interest rate debt.

In 2010, the Company entered into interest rate swap agreements as summarized in the table below:

In November of 2010, the Company entered into a series of treasury rate lock contracts with a total notional value of $100.0 million which were settled in February 2011 for a net pre-tax gain of $4.0 million (each contract was designated and qualified as a cash flow hedge). These contracts were intended to hedge the risks associated with changes in interest rates on a fixed-rate debt issuance that is anticipated to occur prior to June 2012. The gain on these contracts is reflected as a component of other comprehensive income and will be recognized as a deduction to interest expense over the life of the expected fixed rate debt issuance, or recorded as other income in the event the Company determines that it is not probable it will issue fixed rate debt prior to the third quarter of 2012.

Certain of the Company's derivative contracts contain provisions that may require the Company or the counterparties to post collateral based upon the current fair value of the derivative contracts. As of March 31, 2011, the Company was not required to post collateral.

The Company records all derivative instruments on the balance sheet at fair value. As cash flow hedges, the effective portion of the unrealized gain or loss on the derivative instruments is recorded in accumulated other comprehensive income as a separate component of stockholders' equity. Hedge effectiveness is measured by comparing the present value of the cumulative change in the expected future variable cash flows of the hedged contract with the present value of the cumulative change in the expected future variable cash flows of the hedged item. To the extent that the critical terms of the hedged item and the derivative are not identical, hedge ineffectiveness would be reported in earnings as interest expense. Hedge ineffectiveness was not material in any periods presented. As of March 31, 2011, the unrealized gain (before taxes) on the derivative instruments was $3.0 million. The Company does not expect to reclassify any material portion of the unrealized gain into earnings in the next twelve months.

The following summarizes the location and amount of derivative instrument gains and losses (before taxes) reported in the Consolidated Statements of Income:

The following summarizes the location and fair values of derivative instruments on the Consolidated Balance Sheets:

The Company does not hold or issue derivative financial instruments for trading purposes. Interest rate swaps and treasury locks are intended to enable the Company to achieve a level of variable-rate and fixed-rate debt that is acceptable to management and to limit interest rate exposure.

Management has assessed and determined that the Company operates in three business segments representing the Company's three principal distribution channels: Mutual Fund, Institutional and High Net Worth, each of which has different client relationships.

Revenue in the Mutual Fund distribution channel is earned from advisory and sub-advisory relationships with all domestically-registered investment products as well as non-institutional investment products that are registered abroad.

Revenue in the Institutional distribution channel is earned from relationships with foundations and endowments, defined benefit and defined contribution plans and Taft-Hartley plans. Revenue in the High Net Worth distribution channel is earned from relationships with high net worth individuals, family trusts and managed account programs.

Revenue earned from client relationships managed by Affiliates accounted for under the equity method is not consolidated with the Company's reported revenue but instead is included (net of operating expenses, including amortization) in "Income from equity method investments," and reported in the distribution channel in which the Affiliate operates. Income tax attributable to the profits of the Company's equity-method Affiliates is reported within the Company's consolidated income tax provision.

In firms with revenue sharing arrangements, a certain percentage of revenue is allocated for use by management of an Affiliate in paying operating expenses of that Affiliate, including salaries and bonuses, and is called an "Operating Allocation." In reporting segment operating expenses, Affiliate expenses are allocated to a particular segment on a pro rata basis with respect to the revenue generated by that Affiliate in such segment. Generally, as revenue increases, additional compensation is typically paid to Affiliate management partners from the Operating Allocation. As a result, the contractual expense allocation pursuant to a revenue sharing arrangement may result in the characterization of any growth in profit margin beyond the Company's Owners' Allocation as an operating expense. All other operating expenses (excluding intangible amortization) and interest expense have been allocated to segments based on the proportion of cash flow distributions reported by Affiliates in each segment.

		For the Three Months Ended March 31, 2010

		Mutual Fund			Institutional			High Net Worth			Total
Revenue		$	97.9		$	121.8		$	31.3		$	251.0
Operating expenses:
	Depreciation and other amortization		2.2			7.4			2.3			11.9
	Other operating expenses		66.7			83.4			20.5			170.6

			68.9			90.8			22.8			182.5

Operating income			29.0			31.0			8.5			68.5

Non-operating (income) and expenses:
	Investment and other income		(0.8	)		(1.3	)		(0.7	)		(2.8	)
	Income from equity method investments		(0.3	)		(7.8	)		(1.0	)		(9.1	)
	Investment income from Affiliate investments in partnerships		(0.1	)		(0.2	)		(3.8	)		(4.1	)
	Interest expense		6.0			11.1			2.7			19.8

			4.8			1.8			(2.8	)		3.8

Income before income taxes			24.2			29.2			11.3			64.7
Income taxes			5.5			5.0			1.4			11.9

Net income			18.7			24.2			9.9			52.8
	Net income (non-controlling interests)		(11.0	)		(16.4	)		(3.9	)		(31.3	)
	Net income (non-controlling interests in partnerships)		(0.1	)		(0.1	)		(3.8	)		(4.0	)

Net Income (controlling interest)		$	7.6		$	7.7		$	2.2		$	17.5

		For the Three Months Ended March 31, 2011

		Mutual Fund			Institutional			High Net Worth			Total
Revenue		$	184.2		$	207.0		$	35.1		$	426.3
Operating expenses:
	Depreciation and other amortization		4.1			19.7			2.1			25.9
	Other operating expenses		126.4			127.0			22.1			275.5

			130.5			146.7			24.2			301.4

Operating income			53.7			60.3			10.9			124.9

Non-operating (income) and expenses:
	Investment and other income		(2.3	)		(5.0	)		(1.4	)		(8.7	)
	Income from equity method investments		(1.4	)		(7.7	)		(1.1	)		(10.2	)
	Investment income from Affiliate investments in partnerships		—			—			—			—
	Interest expense		10.8			14.6			2.3			27.7

			7.1			1.9			(0.2	)		8.8

Income before income taxes			46.6			58.4			11.1			116.1
Income taxes			11.7			12.8			2.2			26.7

Net income			34.9			45.6			8.9			89.4
	Net income (non-controlling interests)		(18.3	)		(27.2	)		(4.8	)		(50.3	)
	Net income (non-controlling interests in partnerships)		—			—			—			—

Net Income (controlling interest)		$	16.6		$	18.4		$	4.1		$	39.1

Balance Sheet Information
Total assets as of December 31, 2010		$	1,847.9		$	3,009.3		$	434.0		$	5,291.2
Total assets as of March 31, 2011			1,955.2			2,872.7			431.4			5,259.3

The following table presents the change in goodwill during the three months ended March 31, 2011:

The following table reflects the components of intangible assets of the Company's Affiliates that are consolidated as of December 31, 2010 and March 31, 2011:

For the Company's Affiliates that are consolidated, definite-lived acquired client relationships are amortized over their expected useful lives. As of March 31, 2011, these relationships were being amortized over a weighted average life of approximately 10 years. The Company estimates that its consolidated annual amortization expense will be approximately $88.5 million for the next five years, assuming no additional investments in new or existing Affiliates.

The definite-lived acquired client relationships attributable to the Company's equity method investments are amortized over their expected useful lives. As of March 31, 2011, these relationships were being amortized over approximately seven years. Amortization expense for these relationships was $8.4 million for the three months ended March 31, 2011. Assuming no additional investments in new or existing Affiliates, the Company estimates the annual amortization expense attributable to its current equity-method Affiliates for the next five years as follows:

Many of the Company's operating agreements provide the Company a conditional right to call and Affiliate partners the conditional right to put their retained equity interests at certain intervals. The purchase price of these conditional purchases are generally calculated based upon a multiple of the Affiliate's cash flow distributions, which is intended to represent fair value. Affiliate management partners are also permitted to sell their equity interests to other individuals or entities in certain cases, subject to the Company's approval or other restrictions. The Company may pay for Affiliate equity purchases in cash, shares of its common stock or other forms of consideration and can consent to the transfer of these interests to other individuals or entities.

The current redemption value of these interests has been presented as "Redeemable non-controlling interests" on the Company's Consolidated Balance Sheets. Changes in the current

redemption value are recorded to Additional paid-in capital. The following table presents the changes in Redeemable non-controlling interests during the period:

During the three months ended March 31, 2010 and 2011, the Company acquired interests from and transferred interests to Affiliate management partners. The following schedule discloses the effect of changes in the Company's ownership interest in its Affiliates on the controlling interest's equity:

The components of accumulated other comprehensive income, net of applicable taxes, are as follows:

Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations

When used in this Quarterly Report on Form 10-Q, in our other filings with the United States Securities and Exchange Commission, in our press releases and in oral statements made with the approval of an executive officer, the words or phrases "will likely result," "are expected to," "will continue," "is anticipated," "may," "intends," "believes," "estimate," "project" or similar expressions are intended to identify "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are subject to certain risks and uncertainties, including, among others, the following:

These factors (among others) could affect our financial performance and cause actual results to differ materially from historical earnings and those presently anticipated and projected. We will not undertake and we specifically disclaim any obligation to release publicly the result of any revisions which may be made to any forward-looking statements to reflect events or circumstances after the date of such statements or to reflect the occurrence of events, whether or not anticipated. In that respect, we wish to caution readers not to place undue reliance on any such forward-looking statements, which speak only as of the date made.

Management's Discussion and Analysis should be read in conjunction with the Consolidated Financial Statements of AMG and its subsidiaries (collectively, the "Company" or "AMG") and the notes thereto contained elsewhere in this Quarterly Report on Form 10-Q.

We are a global asset management company with equity investments in leading boutique investment management firms (our "Affiliates"). Our innovative partnership approach allows each Affiliate's management team to own significant equity in their firm while maintaining operational autonomy. Our strategy is to generate growth through the internal growth of existing Affiliates, as well as through investments in new Affiliates. In addition, we provide centralized assistance to our Affiliates in strategic matters, marketing, distribution, product development and operations.

As of March 31, 2011, we manage approximately $340 billion in assets through our Affiliates in more than 350 investment products across a broad range of asset classes and investment styles in three principal distribution channels: Mutual Fund, Institutional and High Net Worth. We believe that our diversification across asset classes, investment styles and distribution channels helps to mitigate our

exposure to the risks created by changing market environments. The following summarizes our operations in our three principal distribution channels.

In making investments in boutique investment management firms, we seek to partner with the highest quality firms in the industry, with outstanding management teams, strong long-term performance records and a demonstrated commitment to continued growth and success. Fundamental to our investment approach is the belief that Affiliate management equity ownership (along with AMG's ownership) aligns our interests and provides Affiliate managers with a powerful incentive to continue to grow their business. Our investment structure provides a degree of liquidity and diversification to principal owners of boutique investment management firms, while at the same time expanding equity ownership opportunities among the firm's management and allowing management to continue to participate in the firm's future growth. Our partnership approach also ensures that Affiliates maintain operational autonomy in managing their business, thereby preserving their firm's entrepreneurial culture and independence.

Although the specific structure of each investment is highly tailored to meet the needs of a particular Affiliate, in all cases, we establish a meaningful equity interest in the firm, with the remaining equity interests retained by the management of the Affiliate. Each Affiliate is organized as a separate firm, and its operating or shareholder agreement is structured to provide appropriate incentives for Affiliate management owners and to address the Affiliate's particular characteristics while also enabling us to protect our interests, including through arrangements such as long-term employment agreements with key members of the firm's management team.

In most cases, we own a majority of the equity interests of a firm and structure a revenue sharing arrangement, in which a percentage of revenue is allocated for use by management of that Affiliate in paying operating expenses of the Affiliate, including salaries and bonuses. We call this the "Operating Allocation." The portion of each Affiliate's revenue that is allocated to the owners of that Affiliate (including us) is called the "Owners' Allocation." Each Affiliate allocates its Owners' Allocation to its managers and to us generally in proportion to their and our respective ownership interests in that Affiliate.

One of the purposes of our revenue sharing arrangements is to provide ongoing incentives for Affiliate managers by allowing them to participate in the growth of their firm's revenue, which may increase their compensation from both the Operating Allocation and the Owners' Allocation. These arrangements also provide incentives to control operating expenses, thereby increasing the portion of the Operating Allocation that is available for growth initiatives and compensation.

An Affiliate's Operating Allocation is structured to cover its operating expenses. However, should actual operating expenses exceed the Operating Allocation, our contractual share of cash under the Owners' Allocation generally has priority over the allocations and distributions to the Affiliate's managers. As a result, the excess expenses first reduce the portion of the Owners' Allocation allocated to the Affiliate's managers until that portion is eliminated, before reducing the portion allocated to us. Any such reduction in our portion of the Owners' Allocation is required to be paid back to us out of the portion of future Owners' Allocation allocated to the Affiliate's managers.

Our minority investments are also structured to align our interests with those of the Affiliate's management through shared equity ownership, as well as to preserve the Affiliate's entrepreneurial culture and independence by maintaining the Affiliate's operational autonomy. In cases where we hold a minority investment, the revenue sharing arrangement generally allocates a percentage of the Affiliate's revenue to us. The remaining revenue is used to pay operating expenses and profit distributions to the other owners. Generally where we own a minority investment, we are required to use the equity method of accounting. Consistent with this method, we have not consolidated the operating results of these firms (including their revenue) in our Consolidated Statements of Income. Our share of these firms' profits (net of intangible amortization) is reported in "Income from equity method investments," and is therefore reflected in our Net Income and EBITDA. As a consequence, increases or decreases in these firms' assets under management ($78.6 billion as of March 31, 2011 and included in our reported assets under management) will not affect reported revenue in the same manner as changes in assets under management at our other Affiliates.

Certain of our Affiliates operate under profit-based arrangements through which we own a majority of the equity in the firm and receive a share of profits as cash flow, rather than a percentage of revenue through a typical revenue sharing agreement. As a result, we participate fully in any increase or decrease in the revenue or expenses of such firms. In these cases, we participate in a budgeting process and generally provide incentives to management through compensation arrangements based on the performance of the Affiliate.

We are focused on establishing and maintaining long-term partnerships with our Affiliates. Our shared equity ownership gives both us and our Affiliates meaningful incentives to manage their businesses for strong future growth. From time to time, we may consider changes to the structure of our relationship with an Affiliate in order to better support the firm's growth strategy.

During the twelve months ended March 31, 2011, global equity market returns continued to improve; the MSCI EAFE and S&P 500 realized increases of 10.9% and 15.7%, respectively. Our total assets under management grew to $339.8 billion at March 31, 2011, an increase of approximately 46% over March 31, 2010. The growth in our assets under management was the result of the successful completion of new Affiliate investments in Aston Asset Management, Pantheon Ventures and Trilogy Global Advisors ($49.1 billion), investment performance ($42.8 billion) and organic growth of our Affiliates from net client cash flows ($16.9 billion).

The following table provides information regarding the composition of our assets under management:

		December 31, 2010					March 31, 2011

(in billions)		Assets under Management		Percentage of Total			Assets under Management		Percentage of Total
Asset Class:
Equity⁽¹⁾		$	220.4		69	%	$	232.1		68	%
Alternative⁽²⁾			65.3		20	%		71.9		21	%
Fixed Income			34.3		11	%		35.8		11	%

	Total	$	320.0		100	%	$	339.8		100	%

Geography:⁽³⁾
Domestic		$	110.5		34	%	$	115.9		34	%
Global/International			169.1		53	%		180.7		53	%
Emerging Markets			40.4		13	%		43.2		13	%

	Total	$	320.0		100	%	$	339.8		100	%

Our assets under management by asset class increased during the three months ended March 31, 2011 principally as a result of investment performance as well as organic growth from net client cash flows in our Alternative ($3.2 billion) and Equity asset classes ($2.5 billion). The geographic breakdown of our assets under management also benefitted from investment performance and net client cash flows in Global/International ($3.0 billion) and Emerging Markets ($2.5 billion).

The following table presents our Affiliates' reported assets under management by operating segment (which are also referred to as distribution channels in this Quarterly Report on Form 10-Q).

As shown in the assets under management table above, client cash inflows totaled $21.4 billion while client cash outflows totaled $14.9 billion for the three months ended March 31, 2011. Client flows for the three months ended March 31, 2011 occurred across a broad range of product offerings in each of our distribution channels, with no individual cash inflow or outflow having a material impact on our revenue or expenses.

The operating segment analysis presented in the following table is based on average assets under management. For the Mutual Fund distribution channel, average assets under management represents an average of the daily net assets under management. For the Institutional and High Net Worth distribution channels, average assets under management reflects the billing patterns of particular client accounts. For example, assets under management for an account that bills in advance is presented in the table on the basis of beginning of period assets under management while an account that bills in arrears is reflected on the basis of end of period assets under management. We believe that this

analysis more closely correlates to the billing cycle of each distribution channel and, as such, provides a more meaningful relationship to revenue.

		For the Three Months Ended March 31,

(in millions, except as noted)		2010		2011		% Change
Average assets under management (in billions)⁽¹⁾
Mutual Fund		$	47.2	$	87.1		85	%
Institutional			138.1		208.0		51	%
High Net Worth			30.3		35.8		18	%

	Total	$	215.6	$	330.9		53	%

Revenue
Mutual Fund		$	97.9	$	184.2		88	%
Institutional			121.8		207.0		70	%
High Net Worth			31.3		35.1		12	%

	Total	$	251.0	$	426.3		70	%

Net Income (controlling interest)
Mutual Fund		$	7.6	$	16.6		118	%
Institutional			7.7		18.4		139	%
High Net Worth			2.2		4.1		86	%

	Total	$	17.5	$	39.1		123	%

EBITDA⁽²⁾
Mutual Fund		$	20.9	$	38.5		84	%
Institutional			38.1		68.9		81	%
High Net Worth			9.2		10.8		17	%

	Total	$	68.2	$	118.2		73	%

(1): As described above, our average assets under management considers balances used to bill revenue during the reporting period. These amounts also include assets managed by firms whose financial results are not consolidated ($56.6 billion and $76.0 billion for the three months ended March 31, 2010 and 2011, respectively). Assets under management attributable to any investments in new Affiliates are included on a weighted average basis for the period from the closing date of the respective investment.
(2): EBITDA represents earnings before interest expense, income taxes, depreciation and amortization. Our use of EBITDA, including reconciliation to cash flow from operations, is described in greater detail in "Liquidity and Capital Resources—Supplemental Liquidity Measure" on page 34. For purposes of our distribution channel operating results, expenses not incurred directly by Affiliates have been allocated based on the proportion of aggregate cash flow distributions reported by each Affiliate in the particular distribution channel.

Our revenue is generally determined by the level of our assets under management, the portion of our assets across our products and three operating segments, which realize different fee rates, and the recognition of any performance fees. Performance fees are generally measured on absolute or relative investment performance against a benchmark. As a result, the level of performance fees earned can vary significantly from period to period and these fees may not necessarily be correlated to changes in total assets under management.

Our total revenue increased $175.3 million (or 70%) in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, primarily from a 53% increase in average assets under management and our investments in new Affiliates that realize comparatively higher fee rates. The increase in average assets under management resulted principally from our new Affiliate investments, strong investment performance and positive net client cash flows. Performance fees were not a significant component of consolidated revenue in either the three months ended March 31, 2011 or the three months ended March 31, 2010 (approximately 1% of consolidated revenue for both time periods).

Our revenue in the Mutual Fund distribution channel increased $86.3 million (or 88%) in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, primarily from a 85% increase in average assets under management. The increase in average assets under management resulted principally from our new Affiliate investments, strong investment performance and positive net client cash flows.

Our revenue in the Institutional distribution channel increased $85.2 million (or 70%) in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, primarily from a 51% increase in average assets under management and our investments in new Affiliates that realize comparatively higher fee rates. The increase in average assets under management resulted principally from our new Affiliate investments, strong investment performance and positive net client cash flows. Performance fees were not a significant component of consolidated revenue in either the three months ended March 31, 2011 or the three months ended March 31, 2010 (approximately 2% of consolidated revenue for both time periods).

Our revenue in the High Net Worth distribution channel increased $3.8 million (or 12%) in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, primarily from a 18% increase in average assets under management. The increase in average assets under management resulted principally from investment performance.

The substantial portion of our operating expenses is incurred by our Affiliates, the majority of which is incurred by Affiliates with revenue sharing arrangements. For Affiliates with revenue sharing arrangements, an Affiliate's Operating Allocation percentage generally determines its operating expenses. Accordingly, our compensation expense is impacted by increases or decreases in each Affiliate's revenue and the corresponding increases or decreases in each Affiliate's respective Operating Allocation. During the three months ended March 31, 2011, approximately $91.4 million (or 51%) of our consolidated compensation expense was attributable to our Affiliate management partners. The percentage of revenue allocated to operating expenses varies from one Affiliate to another and may also vary within an Affiliate depending on the source or amount of revenue. As a result, changes in our aggregate revenue may not impact our consolidated operating expenses to the same degree.

Compensation and related expenses increased 51% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, primarily as a result of increases in aggregate Affiliate expenses of $37.9 million from new Affiliate investments during 2010, and $13.3 million from the relationship between revenue and operating expenses at extant Affiliates, which experienced increases in revenue, and accordingly, reported higher compensation expenses. This increase was also attributable to increases in holding company incentive and share-based compensation.

Selling, general and administrative increased 93% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010. This increase resulted principally from increases in aggregate Affiliate expenses of $27.9 million from new Affiliate investments as well as increases in sub-advisory and distribution expenses attributable to an increase in assets under management at our Affiliates in the Mutual Fund distribution channel. These increases were partially offset by a $4.5 million decrease in acquisition-related professional fees.

Amortization of intangible assets increased 148% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010. This increase was principally attributable to increases in definite-lived intangible assets resulting from new Affiliate investments.

Depreciation and other amortization increased 27% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally attributable to an increase in aggregate Affiliate expenses from new Affiliate investments.

Other operating expenses increased 39% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally attributable to an increase in aggregate Affiliate expenses from new Affiliate investments.

Income from equity method investments consists of our share of income from Affiliates that are accounted for under the equity method of accounting, net of any related intangible amortization. Income from equity method investments increased 12% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally as a result of increases in assets under management at Affiliates that we account for under the equity method of accounting. For the quarter ended March 31, 2011, income from performance fees earned on our equity method investments ($13.5 million of revenue) was consistent with amounts reported in the quarter ended March 31, 2010.

Investment and other income increased 211% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally as a result of an increase in Affiliate investment earnings, including $4.2 million from new Affiliates.

Investment income from investments in partnerships relates to the consolidation of certain investment partnerships in which our Affiliates are the general partner. In the third quarter of 2010, we deconsolidated these partnerships. For the three months ended March 31, 2010, the income from investments in partnerships was $4.1 million, which was principally attributable to investors who are unrelated to us.

Interest expense increased 21% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally as a result of increased borrowings under our revolving credit facility, which was amended and restated in January 2011 (the "credit facility"), as well as an increase in the cost of credit facility borrowings. The increase was also attributable to a $0.8 million increase in issuance costs related to our credit facility amendment.

Imputed interest expense consists of interest accretion on our senior convertible securities and our junior convertible trust preferred securities as well as the accretion of our projected contingent payment arrangements. Imputed interest expense increased 118% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally as a result of a $4.2 million increase in accretion related to our contingent payment arrangements in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010.

Income taxes increased 124% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, as the result of increases in Income before income taxes and approximately $1.1 million of taxes attributable to non-controlling interests from our 2010 new Affiliate investments.

Net income attributable to non-controlling interests increased 61% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, principally as a result of the previously discussed changes in revenue partially offset by the previously discussed increases in tax expenses.

Net income (non-controlling interest in partnerships) relates to the consolidation of certain investment partnerships in which our Affiliates are the general partner. In the third quarter of 2010, we deconsolidated these partnerships. For the three months ended March 31, 2010, the income from investments in partnerships was $4.0 million.

Net Income (controlling interest) increased 123% in the three months ended March 31, 2011, as compared to the three months ended March 31, 2010, respectively, as a result of the previously discussed increases in revenue, partially offset by increases in reported operating and income tax expenses.

As supplemental information, we provide non-GAAP performance measures that we refer to as Economic Net Income and Economic earnings per share. We consider Economic Net Income an important measure of our financial performance, as we believe it best represents our operating performance before non-cash expenses relating to our acquisition of interests in our investment management firms. Economic Net Income and Economic earnings per share are used by our management and Board of Directors as our principal performance benchmarks, including as measures for aligning executive compensation with stockholder value. These measures are provided in addition to, but not as a substitute for, Net Income (controlling interest) and Earnings per share. Economic Net Income and Economic earnings per share are not liquidity measures and should not be used in place of any liquidity measure calculated under GAAP.

Under our Economic Net Income definition, we add to Net Income (controlling interest) amortization (including equity method amortization), deferred taxes related to intangible assets, non-cash imputed interest expense (principally related to the accounting for convertible securities and contingent payment arrangements) and Affiliate equity expense. We add back amortization attributable to acquired client relationships because this expense does not correspond to the changes in value of these assets, which do not diminish predictably over time. The portion of deferred taxes generally attributable to intangible assets (including goodwill) that we no longer amortize but which continues to generate tax deductions is added back, because we believe it is unlikely these accruals will be used to settle material tax obligations. We add back non-cash expenses relating to certain transfers of equity between Affiliate management partners, when these transfers have no dilutive effect to our shareholders.

Economic earnings per share represents Economic Net Income divided by the adjusted diluted average shares outstanding, which measures the potential share issuance from our senior convertible

securities and junior convertible securities (each further described in Liquidity and Capital Resources) using a "treasury stock" method. Under this method, only the net number of shares of common stock equal to the value of these securities in excess of par, if any, are deemed to be outstanding. We believe the inclusion of net shares under a treasury stock method best reflects the benefit of the increase in available capital resources (which could be used to repurchase shares of common stock) that occurs when these securities are converted and we are relieved of our debt obligation. This method does not take into account any increase or decrease in our cost of capital in an assumed conversion.

In the fourth quarter of 2010, we modified our Economic Net Income definition to no longer add back Affiliate depreciation to Net Income (controlling interest). If we had applied this definition change to the three months ended March 31, 2010, Economic Net Income would have been $48.9 million and Economic earnings per share would have been $1.09, as compared to $50.8 million and $1.14, respectively.

The following table provides a reconciliation of Net Income (controlling interest) to Economic Net Income:

		For the Three Months Ended March 31,

(in millions, except shares and per share data)		2010			2011
Net Income (controlling interest)		$	17.5		$	39.1
	Intangible amortization⁽¹⁾⁽²⁾		16.7			27.1
	Intangible-related deferred taxes		10.7			12.9
	Imputed interest⁽³⁾		2.3			4.4
	Affiliate equity expense		1.7			1.6
	Affiliate depreciation		1.9			—

Economic Net Income		$	50.8		$	85.1

Average shares outstanding—diluted			45.4			53.1
	Assumed issuance of senior convertible securities shares		(0.8	)		—
	Assumed issuance of junior convertible securities shares		—			—
	Dilutive impact of senior convertible securities shares		0.2			—
	Dilutive impact of junior convertible securities shares		—			—

Average shares outstanding—adjusted diluted			44.8			53.1

Economic earnings per share		$	1.14		$	1.60

(1): We are required to use the equity method of accounting for certain of our investments and, as such, do not separately report these Affiliates' revenues or expenses (including intangible amortization) in our income statement. Our share of these investments' amortization, $8.1 million and $8.4 million for the three months ended March 31, 2010 and 2011, respectively, is reported in "Income from equity method investments."
(2): Our reported intangible amortization, $8.9 million and $22.1 million for the three months ended March 31, 2010 and 2011, respectively, includes $0.3 million and $3.4 million, respectively, of amortization attributable to our non-controlling interests, amounts not added back to Net Income (controlling interest) to measure our Economic Net Income.
(3): Our reported imputed interest expense, $3.8 million and $8.3 million for the three months ended March 31, 2010 and 2011, respectively, includes $0.0 million and $1.4 million, respectively, of imputed interest attributable to our non-controlling interests, amounts not added back to Net Income (controlling interest) to measure our Economic Net Income.

Economic Net Income increased 68% in the three months ended March 31, 2011 as compared to the three months ended March 31, 2010, primarily as a result of the previously described factors that caused an increase in Net Income as well as increases in amortization and intangible-related deferred tax expenses.

The following table summarizes certain key financial data relating to our liquidity and capital resources:

We view our ratio of debt to EBITDA (our "internal leverage ratio") as an important gauge of our ability to service debt, make new investments and access additional capital. Consistent with industry practice, we do not consider junior trust preferred securities as debt for the purpose of determining our internal leverage ratio. We also view our leverage on a "net debt" basis by deducting from our debt balance holding company cash. At March 31, 2011, our internal leverage ratio was 1.4:1.

Under the terms of our credit facility we are required to meet two financial ratio covenants. The first of these covenants is a maximum ratio of debt to EBITDA (the "bank leverage ratio") of 3.5. The calculation of our bank leverage ratio is generally consistent with our internal leverage ratio approach. The second covenant is a minimum EBITDA to cash interest expense ratio of 3.0 (our "bank interest coverage ratio"). For the purposes of calculating these ratios, share-based compensation expense is added back to EBITDA. As of March 31, 2011, our actual bank leverage and bank interest coverage ratios were 1.7 and 8.0, respectively, and we were in full compliance with all terms of our credit facility. We have $410 million of remaining capacity under our $750 million credit facility and we could borrow the entire amount and remain in compliance with our credit agreement.

We are rated BBB- by both Standard & Poor's and Fitch rating agencies. With the exception of a modest increase in the borrowing rate under our credit facility (0.50%), a downgrade of our credit rating would have no direct financial effect on any of our agreements or securities (or otherwise trigger a default).

As supplemental information in this Quarterly Report on Form 10-Q, we have provided information regarding our EBITDA, a non-GAAP liquidity measure. This measure is provided in

addition to, but not as a substitute for, cash flow from operations. EBITDA represents earnings before interest expense, income taxes, depreciation and amortization. EBITDA, as calculated by us, may not be consistent with computations of EBITDA by other companies. As a measure of liquidity, we believe that EBITDA is useful as an indicator of our ability to service debt, make new investments and meet working capital requirements. We further believe that many investors use this information when analyzing the financial position of companies in the investment management industry.

The following table provides a reconciliation of cash flow from operations to EBITDA:

		For the Three Months Ended March 31,

(in millions)		2010			2011
Cash flow from operations		$	68.0		$	130.2
	Interest expense, net of non-cash items⁽¹⁾		14.2			16.8
	Current tax provision		2.5			13.5
	Income from equity method investments, net of distributions⁽²⁾		(6.0	)		(46.4	)
	Net income (non-controlling interests)		(31.3	)		(50.3	)
	Net income (non-controlling interests in partnerships)		(4.0	)		—
	Changes in assets and liabilities		28.3			65.1
	Other non-cash adjustments⁽³⁾		(3.5	)		(10.7	)

EBITDA		$	68.2		$	118.2

In the three months ended March 31, 2011, we met our cash requirements primarily through cash generated by operating activities. Our principal uses of cash in the three months ended March 31, 2011 were to make distributions to Affiliate managers and repay our senior bank debt. We expect that our principal uses of cash for the foreseeable future will be for investments in new and existing Affiliates, distributions to Affiliate managers, payment of principal and interest on outstanding debt, and for working capital purposes.

The following table summarizes the principal amount due at maturity of our debt obligations and convertible securities as of March 31, 2011:

Under the credit facility, we pay interest based on a LIBOR rate or the prime rate (plus an applicable spread, which varies depending on our credit rating). Subject to the agreement of lenders to provide additional commitments, we have the option to increase the credit facility by up to $150 million. The credit facility is unsecured and contains financial covenants with respect to leverage and interest coverage and customary affirmative and negative covenants, including limitations on indebtedness, liens, cash dividends and fundamental corporate changes. As of March 31, 2011, we had $340 million outstanding under the credit facility.

At March 31, 2011, we have one senior convertible security outstanding ("2008 senior convertible notes") and two junior convertible trust preferred securities outstanding, one issued in 2006 (the "2006 junior convertible trust preferred securities") and a second issued in 2007 (the "2007 junior convertible trust preferred securities"). The principal terms of these securities are summarized below.

	2008 Senior Convertible Notes		2007 Junior Convertible Trust Preferred Securities		2006 Junior Convertible Trust Preferred Securities

Issue Date	August 2008		October 2007		April 2006
Maturity Date	August 2038		October 2037		April 2036
Next Potential Put Date	August 2013		N/A		N/A
Par Value	$460.0		$430.8		$300.0
Carrying Value⁽¹⁾	425.5		296.6		213.9
Note Denomination	1,000		50		50
Current Conversion Rate	7.959		0.250		0.333
Current Conversion Price	$125.65		$200.00		$150.00
Stated Coupon	3.95	%	5.15	%	5.10	%
Coupon Frequency	Semi-annually		Quarterly		Quarterly
Tax Deduction Rate⁽²⁾	9.38	%	8.00	%	7.50	%

From time to time, we seek to offset our exposure to changing interest rates under our debt financing arrangements by entering into interest rate hedging contracts. These instruments are designated as cash flow hedges with changes in fair value recorded in other comprehensive income for the effective portion of the hedge.

We have entered into interest rate swap contracts to exchange a fixed rate for the variable rate on our credit facility. These contracts expire between 2015 and 2017. Under these contracts, we will pay a weighted average fixed rate of 1.76% on a notional amount of $100.0 million through October 2015. Thereafter, through October 2017, we will pay a weighted average fixed rate of 2.14% on a remaining notional amount of $25 million. As of March 31, 2011, the unrealized gain on these contracts was $3.0 million.

We also entered into treasury rate lock agreements with a notional value of $100.0 million to hedge an anticipated issuance of fixed-rate debt. These contracts were settled in February 2011 for a net pre-tax gain of $4.0 million.

During 2009, we entered into a forward equity sale agreement with a major securities firm to sell shares of our common stock, and extended this agreement in April 2011. As of March 31, 2011, no forward equity sales are outstanding. We may sell up to an additional $103.5 million under this agreement.

Our Board of Directors has authorized share repurchase programs in recent periods. The maximum number of shares that may yet be repurchased under outstanding programs is approximately 1.6 million. The timing and amount of issuances and repurchases are determined at the discretion of our management.

Many of our operating agreements provide us a conditional right to call and Affiliate partners the conditional right to put their retained equity interests at certain intervals. The purchase price of these conditional purchases are generally calculated based upon a multiple of the Affiliate's cash flow distributions, which is intended to represent fair value. Affiliate management partners are also permitted to sell their equity interests to other individuals or entities in certain cases, subject to our approval or other restrictions. We may pay for Affiliate equity purchases in cash, shares of our common stock or other forms of consideration and can consent to the transfer of these interests to other individuals or entities.

Our current redemption value for these interests has been presented as "Redeemable non-controlling interests" on our Consolidated Balance Sheets. Although the timing and amounts of these purchases are difficult to predict, we expect to repurchase approximately $100 million of Affiliate equity during the next twelve months, and, in such event, will own the cash flow associated with any equity repurchased.

Cash flow from operations generally represents Net Income plus non-cash charges for amortization, deferred taxes, equity-based compensation and depreciation, as well as increases and decreases in our consolidated working capital.

The increase in cash flows from operations for the three months ended March 31, 2011 as compared to the three months ended March 31, 2010, resulted principally from an increase in Net Income of $36.6 million, an increase in distributions from equity method investments of $41.7 million and a decrease in collection of unsettled shares receivable of $38.0 million, partially offset by a decrease in payments of unsettled shares payable of $53.9 million and an increase in accounts payable and accrued liabilities of $19.5 million.

The net cash flow used in investing activities decreased $119.8 million for the three months ended March 31, 2011 as compared to the three months ended March 31, 2010. This was primarily the result of a $114.4 million decrease in cash flow used for new Affiliate investments in 2011, as compared to 2010.

Net cash flows used in financing activities increased $188.4 million for the three months ended March 31, 2011, as compared to the three months ended March 31, 2010. This was primarily a result of repayments of the credit facility for the three months ended March 31, 2011 (as compared to net borrowings for the three months ended March 31, 2010), partially offset by a decrease in repurchases of Affiliate equity of $94.8 million.

In the second quarter of 2011, we will make a payment of approximately $63.8 million representing the deferred purchase price from our Pantheon Ventures acquisition. We are also contingently liable, upon achievement of specified financial targets, to make payments of up to $496.5 million through 2015 under past acquisition agreements. In 2011, we expect to make total payments of approximately $1.4 million to settle portions of these contingent obligations and we expect to repurchase about $100.0 million of interests in certain existing Affiliates in 2011.

We anticipate that borrowings under the credit facility and proceeds from the settlement of any forward equity sales, together with cash flows from operations will be sufficient to support our cash flow needs for the foreseeable future.

The following table summarizes our contractual obligations as of March 31, 2011:

			Payments Due

			Remainder of 2011
(in millions)	Total				2012-2013		2014-2015		Thereafter
Contractual Obligations	Total				2012-2013		2014-2015		Thereafter
Senior bank debt	$	340.0	$	—	$	340.0	$	—	$	—
Senior convertible securities⁽¹⁾		959.6		9.1		36.3		36.3		877.9
Junior convertible trust preferred securities		1,690.2		27.8		74.1		74.1		1,514.2
Leases		123.8		18.4		42.5		32.0		30.9
Other liabilities⁽²⁾		122.0		80.5		—		—		41.5

Total Contractual Obligations	$	3,235.6	$	135.8	$	492.9	$	142.4	$	2,464.5

Contingent Obligations
Contingent payment obligations⁽³⁾	$	128.8	$	1.4	$	93.9	$	33.5	$	—

(1): The timing of debt payments assumes that outstanding debt is settled for cash or common stock at the applicable maturity dates. The amounts include the cash payment of fixed interest. Holders of the 2008 convertible notes may put their interests to us for $460 million in 2013.
(2): Other liabilities reflect amounts payable to Affiliate managers related to our purchase of additional Affiliate equity interests and deferred purchase price payments for acquisitons. This table does not include liabilities for uncertain tax positions or commitments to co-invest in certain investment partnerships (of $24.6 million and $98.6 million as of March 31, 2011, respectively) as we cannot predict when such obligations will be paid.
(3): The amount of contingent payments related to business acquisitions disclosed in the table represents our expected settlement amounts. The maximum settlement amount through 2011 is $54.1 million and $442.4 million in periods thereafter.

There have been no significant changes to our Quantitative and Qualitative Disclosures About Market Risk in the three months ended March 31, 2011. Please refer to Item 7A in our 2010 Annual Report on Form 10-K.

We carried out an evaluation under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, of the effectiveness of the design and operation of our disclosure controls and procedures during the quarter covered by this Quarterly Report on Form 10-Q. Based upon that evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, as of the end of the quarter covered by this Quarterly Report on Form 10-Q, our disclosure controls and procedures are effective in ensuring that (i) the information required to be disclosed by us in the reports that we file or submit under the Securities Exchange Act of 1934, as amended (the "Exchange Act") is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission's rules and forms, and (ii) such information is accumulated and communicated to our management, including our principal executive officer and principal financial officers as appropriate to allow timely decisions regarding required disclosure. In designing and evaluating our disclosure controls and procedures, we recognize that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and our management necessarily was required to apply its judgment in evaluating and implementing possible controls and procedures. Our disclosure controls and procedures were designed to provide reasonable assurance of achieving their stated objectives and our principal executive officer and principal financial officers concluded that our disclosure controls and procedures are effective at the reasonable assurance level. We review on an ongoing basis and document our disclosure controls and procedures, and our internal control over financial reporting, and we may from time to time make changes in an effort to enhance their effectiveness and ensure that our systems evolve with our business.

No change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) occurred during the quarter covered by this Quarterly Report on Form 10-Q that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

The Sarbanes-Oxley Act of 2002 provides that recent business combinations may be excluded from internal controls assessment; consequently, management will include Pantheon Ventures and Trilogy Global Advisors in our assessment of internal control over financial reporting as of December 31, 2011.

The exhibits are listed on the Exhibit Index and are included elsewhere in this Quarterly Report on Form 10-Q.

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.

Exhibit No.			Description

	10.1		Transition and Advisory Services Agreement by and between Affiliated Managers Group, Inc. and Darrell W. Crate dated as of February 1, 2011.
	31.1		Certification of Registrant's Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
	31.2		Certification of Registrant's Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
	32.1		Certification of Registrant's Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
	32.2		Certification of Registrant's Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
	101		The following financial statements from the Registrant's Quarterly Report on Form 10-Q for the quarter ended March 31, 2011 are furnished herewith, formatted in XBRL (eXtensible Business Reporting Language): (i) the Consolidated Statements of Income for the three month periods ended March 31, 2011 and 2010, (ii) the Consolidated Balance Sheets at March 31, 2011 and December 31, 2010, (iii) the Consolidated Statement of Equity for the three month period ended March 31, 2011, (iv) the Consolidated Statements of Cash Flows for the three month periods ended March 31, 2011 and 2010, and (v) the Notes to the Consolidated Financial Statements.


(Mark One)
ý		QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended March 31, 2011
OR
o		TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from to


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


Large accelerated filer ý		Accelerated filer o		Non-accelerated filer o(Do not check if a smaller reporting company)		Smaller reporting company o

	December 31, 2010		March 31, 2011

Cost of investments in marketable securities	$	68.9	$	63.0
Gross unrealized gains		47.1		47.3
Gross unrealized losses		—		—

	December 31, 2010				March 31, 2011

Category of Investment	Fair Value		Unfunded Commitments		Fair Value		Unfunded Commitments
Private equity fund-of-funds⁽¹⁾	$	85.7	$	89.2	$	93.6	$	98.6
Other funds⁽²⁾		55.2		—		64.0		—

	$	140.9	$	89.2	$	157.6	$	98.6

		December 31, 2010				March 31, 2011

		Carrying Value		Principal amount at maturity		Carrying Value		Principal amount at maturity
Senior convertible securities:
	2008 senior convertible notes⁽¹⁾	$	422.1	$	460.0	$	425.5	$	460.0

Junior convertible trust preferred securities:
	2007 junior convertible trust preferred securities⁽¹⁾	$	296.3	$	430.8	$	296.6	$	430.8
	2006 junior convertible trust preferred securities⁽¹⁾		213.6		300.0		213.9		300.0

	Total junior convertible securities	$	509.9	$	730.8	$	510.5	$	730.8

		For the Three Months Ended March 31,

		2010			2011
Current:
	Federal	$	(0.8	)	$	6.1
	State		1.2			3.1
	Foreign		2.9			7.9

Total Current			3.3			17.1

Deferred:
	Federal		7.9			11.3
	State		1.2			0.7
	Foreign		(0.5	)		(2.4	)

Total Deferred			8.6			9.6

Provision for Income Taxes		$	11.9		$	26.7

	Level 3 Financial Assets and Financial Liabilities at Fair Value

Three Months Ended March 31, 2010	Balance, beginning of period		Net realized gains/losses			Net unrealized gains/losses relating to instruments still held at the reporting date			Purchases and issuances		Settlements and reductions			Net transfers in and/or out of Level 3			Balance, end of period
Partnership investments	$	4.0	$	—	⁽¹⁾	$	—	⁽¹⁾	$	—	$	—		$	(3.7	)	$	0.3
Contingent payment obligations		27.1		—	⁽²⁾		—	⁽²⁾		49.1		(27.1	)		—			49.1
Obligations to related parties		78.7		(0.2	)⁽³⁾		—	⁽³⁾		15.3		(78.5	)		—			15.3

	Level 3 Financial Assets and Financial Liabilities at Fair Value

Three Months Ended March 31, 2011	Balance, beginning of period		Net realized gains/losses			Net unrealized gains/losses relating to instruments still held at the reporting date			Purchases and issuances		Settlements and reductions			Net transfers in and/or out of Level 3		Balance, end of period
Partnership investments	$	85.8	$	1.1	⁽¹⁾	$	5.6	⁽¹⁾	$	2.8	$	(1.7	)	$	—	$	93.6
Contingent payment obligations		84.0		—	⁽²⁾		5.4	⁽²⁾		—		—			—		89.4
Obligations to related parties		79.6		0.3	⁽³⁾		2.5	⁽³⁾		9.6		(24.1	)		—		67.9

	December 31, 2010				March 31, 2011

	Unconsolidated VIE Net Assets		Carrying Value and Maximum Exposure to Loss		Unconsolidated VIE Net Assets		Carrying Value and Maximum Exposure to Loss
Sponsored investment funds	$	3,350.7	$	0.9	$	3,524.6	$	0.8
Trust preferred vehicles		9.0		9.0		9.0		9.0

				Weighted Average Exercise Price

Unexercised options outstanding—January 1, 2011		5.1		$	62.34
	Options granted	—			—
	Options exercised	(0.3	)		48.03
	Options forfeited	—			—

Unexercised options outstanding—March 31, 2011		4.8			63.27	4.9

Exercisable at March 31, 2011		2.4			58.49	4.0

	Notional Amount				Receiving	Start Date	Expiration Date

Counterparty A	$	25.0	1.67	%	3-Month LIBOR	October 2010	October 2015
Counterparty A	$	25.0	1.65	%	3-Month LIBOR	October 2010	October 2015
Counterparty B	$	25.0	1.59	%	3-Month LIBOR	October 2010	October 2015
Counterparty B	$	25.0	2.14	%	3-Month LIBOR	October 2010	October 2017

	December 31, 2010		March 31, 2011

Cash Flow Hedges
Interest rate swaps⁽¹⁾	$	2.5	$	3.0
Treasury rate locks⁽¹⁾		3.4		—

Total	$	5.9	$	3.0

	Mutual Fund		Institutional		High Net Worth		Total

Balance, as of December 31, 2010	$	785.9	$	1,083.7	$	261.6	$	2,131.2
Goodwill acquired		1.9		0.1		—		2.0
Foreign currency translation		2.4		4.5		2.5		9.4

Balance, as of March 31, 2011	$	790.2	$	1,088.3	$	264.1	$	2,142.6

		December 31, 2010				March 31, 2011

		Carrying Amount		Accumulated Amortization		Carrying Amount		Accumulated Amortization
Amortized intangible assets:
	Acquired client relationships	$	974.8	$	228.6	$	976.5	$	250.7
Non-amortized intangible assets:
	Acquired client relationships-mutual fund management contracts		678.0		—		683.8		—
	Goodwill		2,131.2		—		2,142.6		—

Year Ending December 31,	Estimated Amortization Expense

2011	$	32.9
2012		32.8
2013		32.8
2014		11.3
2015		4.1


Balance as of January 1, 2011	$	406.3
Issuance of Redeemable non-controlling interest		48.5
Repurchase of Redeemable non-controlling interest		(7.0	)
Changes in redemption value		83.4

Balance as of March 31, 2011	$	531.2

	December 31, 2010		March 31, 2011

Foreign currency translation adjustments	$	67.9	$	82.1
Unrealized gain on derivative securities		3.7		4.4
Unrealized gain on investment securities		28.9		25.4

Accumulated other comprehensive income	$	100.5	$	111.9

	For the Three Months Ended March 31,

(in millions, except as noted and per share data)	2010		2011		% Change
Assets under Management (in billions)	$	232.1	$	339.8		46	%
Revenue		251.0		426.3		70	%
Net Income (controlling interest)		17.5		39.1		123	%
Earnings per share—diluted		0.38		0.74		95	%
Economic Net Income⁽¹⁾		50.8		85.1		68	%
Economic earnings per share⁽¹⁾		1.14		1.60		40	%
EBITDA⁽²⁾		68.2		118.2		73	%

Statement of Changes-Quarter to Date (in billions)			Mutual Fund			Institutional			High Net Worth			Total

December 31, 2010			$	85.2		$	200.1		$	34.7		$	320.0
	Client cash inflows			7.0			12.7			1.7			21.4
	Client cash outflows			(4.8	)		(8.4	)		(1.7	)		(14.9	)

		Net client cash flows		2.2			4.3			—			6.5

	Other⁽¹⁾			(0.2	)		—			—			(0.2	)
	Investment performance			3.4			8.3			1.8			13.5

March 31, 2011			$	90.6		$	212.7		$	36.5		$	339.8

(in millions)	December 31, 2010		March 31, 2011

Balance Sheet Data
Cash and cash equivalents	$	313.3	$	252.8
Senior bank debt		460.0		340.0
2008 senior convertible notes		422.1		425.5
Junior convertible trust preferred securities		509.9		510.5

	For the Three Months Ended March 31,

	2010			2011
Cash Flow Data
Operating cash flow	$	68.0		$	130.2
Investing cash flow		(131.9	)		(12.1	)
Financing cash flow		7.6			(180.8	)
EBITDA⁽¹⁾		68.2			118.2


		AFFILIATED MANAGERS GROUP, INC.
May 10, 2011		/s/ JAY C. HORGEN Jay C. Horgen on behalf of the Registrant as Chief Financial Officer and Treasurer (and also as Principal Financial and Principal Accounting Officer)