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                                                                   EXHIBIT 4.24


                          REGISTRATION RIGHTS AGREEMENT

            THIS REGISTRATION RIGHTS AGREEMENT (this "Agreement") is made and
entered into as of February 25, 2003, by and between AFFILIATED MANAGERS GROUP,
INC., a Delaware corporation (the "Company") and MERRILL LYNCH & CO., MERRILL
LYNCH, PIERCE, FENNER & SMITH INCORPORATED (the "Initial Purchaser").

            This Agreement is made pursuant to the Purchase Agreement, dated
February 19, 2003 (the "Purchase Agreement"), between the Company, as issuer of
the Floating Rate Convertible Senior Debentures due 2033 (the "Debentures"), and
the Initial Purchaser, which provides for, among other things, the sale by the
Company to the Initial Purchaser of the aggregate principal amount at maturity
of Debentures specified therein. In order to induce the Initial Purchaser to
enter into the Purchase Agreement, the Company has agreed to provide the
registration rights set forth in this Agreement. The execution of this Agreement
is a condition to the closing under the Purchase Agreement.

            The Company agrees with the Initial Purchaser, (i) for its benefit
as Initial Purchaser and (ii) for the benefit of the beneficial owners
(including the Initial Purchaser) from time to time of the Debentures, and the
beneficial owners from time to time of the Underlying Common Stock (as defined
herein) issued upon conversion of the Debentures, if any, (each of the foregoing
a "Holder" and together the "Holders"), as follows:

     SECTION 1. DEFINITIONS. Capitalized terms used herein without definition
shall have their respective meanings set forth in the Purchase Agreement. As
used in this Agreement, the following terms shall have the following meanings:

            "Affiliate:" With respect to any specified person, an "affiliate,"
as defined in Rule 144, of such person.

            "Applicable Conversion Price:" The Applicable Conversion Price as of
any date of determination means per $1,000 principal amount at maturity of
Debentures as of such date of determination divided by the Conversion Rate in
effect as of such date of determination or, if no Debentures are then
outstanding, the Conversion Rate that would be in effect were Debentures then
outstanding.

            "Business Day:" Each Monday, Tuesday, Wednesday, Thursday and Friday
that is not a day on which banking institutions in The City of New York are
authorized or obligated by law or executive order to close.

            "Common Stock:" The Common Stock, $0.01 par value, of the Company
and any other shares of common stock as may constitute "Common Stock" for
purposes of the Indenture, including the Underlying Common Stock.

            "Company:" See the first paragraph hereof.

            "Conversion Rate:" Conversion Rate shall have the meaning assigned
to such term in the Indenture.

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            "Damages Accrual Period:" See Section 2(e) hereof.

            "Damages Payment Date:" Each February 25, May 25, August 25 and
November 25.

            "Debentures:" See the second paragraph hereof.

            "Deferral Notice:" See Section 3(h) hereof.

            "Deferral Period:" See Section 3(h) hereof.

            "Effectiveness Deadline Date:" See Section 2(a) hereof.

            "Effectiveness Period:" The period beginning on the Issue Date and
ending on the earlier of (i) the sale pursuant to the Initial Shelf Registration
Statement of all Registrable Securities thereunder and (ii) the expiration of
the holding period applicable to such Registrable Securities held by persons not
Affiliates of the Company under Rule 144(k) under the Securities Act.

            "Event:" See Section 2(e) hereof.

            "Event Date:" See Section 2(e) hereof.

            "Event Termination Date:" See Section 2(e) hereof.

            "Exchange Act:" The Securities Exchange Act of 1934, as amended, and
the rules and regulations of the SEC promulgated thereunder.

            "Filing Deadline Date:" See Section 2(a) hereof.

            "Holder:" See the third paragraph hereof.

            "Indenture:" The senior indenture, dated as of the date hereof,
between the Company and The Bank of New York, as trustee, pursuant to which the
Debentures are being issued.

            "Initial Purchaser:" See the first paragraph of this Agreement.

            "Initial Shelf Registration Statement:" See Section 2(a) hereof.

            "Issue Date:" means February 25, 2003.

            "Liquidated Damages Amount:" See Section 2(e) hereof.

            "Material Event:" See Section 3(h) hereof.

            "Notice and Questionnaire:" A written notice delivered to the
Company containing substantially the information called for by the Selling
Securityholder Notice and

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Questionnaire attached as Annex A to the Offering Memorandum of the Company,
dated February 19, 2003, relating to the Debentures.

            "Notice Holder:" On any date, any Holder that has delivered a Notice
and Questionnaire to the Company on or prior to such date.

            "Prospectus:" The prospectus included in any Registration Statement
(including, without limitation, a prospectus that discloses information
previously omitted from a prospectus filed as part of an effective registration
statement in reliance upon Rule 415 promulgated under the Securities Act), as
amended or supplemented by any amendment or prospectus supplement, including
post-effective amendments, and all materials incorporated by reference in such
Prospectus.

            "Purchase Agreement:" See the second paragraph hereof.

            "Record Date:" With respect to any Damages Payment Date relating to
any Debenture as to which any Liquidated Damages Amount has accrued, (i) the
15th day immediately preceding such Damages Payment Date if the Damages Accrual
Period has not ended, or (ii) the date of the end of the Damages Accrual Period.

            "Record Holder:" With respect to any Damages Payment Date relating
to any Debenture as to which any Liquidated Damages Amount has accrued, the
registered holder of such Debenture.

            "Registrable Securities:" The Securities, until such securities have
been converted or exchanged and, at all times subsequent to any such conversion
or exchange, any securities into or for which such securities have been
converted or exchanged, and any security issued with respect thereto upon any
stock dividend, split, merger or similar event until, in the case of any such
security, the earliest of (i) its effective registration under the Securities
Act and resale in accordance with the Registration Statement covering it, (ii)
expiration of the holding period that would be applicable thereto under Rule
144(k) were it not held by an Affiliate of the Company, (iii) its sale to the
public pursuant to Rule 144 or (iv) the expiration of the Effectiveness Period.

            "Registration Statement:" Any registration statement of the Company
that covers any of the Registrable Securities pursuant to the provisions of this
Agreement, including the Prospectus, amendments and supplements to such
registration statement, including post-effective amendments, all exhibits, and
all materials incorporated by reference in such registration statement.

            "Restricted Securities:" As this term is defined in Rule 144.

            "Rule 144:" Rule 144 under the Securities Act, as such Rule may be
amended from time to time, or any similar rule or regulation hereafter adopted
by the SEC.

            "Rule 144A:" Rule 144A under the Securities Act, as such Rule may be
amended from time to time, or any similar rule or regulation hereafter adopted
by the SEC.

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            "SEC:" The Securities and Exchange Commission.

            "Securities:" Collectively means the Debentures and the Underlying
Common Stock.

            "Securities Act:" The Securities Act of 1933, as amended, and the
rules and regulations promulgated by the SEC thereunder.

            "Shelf Registration Statement:" See Section 2(a) hereof.

            "Subsequent Shelf Registration Statement:" See Section 2(b) hereof.

            "TIA:" The Trust Indenture Act of 1939, as amended.

            "Trustee:" The Bank of New York (or any successor entity), the
Trustee under the Indenture.

            "Underlying Common Stock:" The Common Stock into which the
Debentures are convertible or issued upon any such conversion.

     SECTION 2. SHELF REGISTRATION.

            (a)   The Company shall prepare or cause to be prepared and shall
use reasonable efforts to file or cause to be filed with the SEC no later than a
date which is ninety (90) days after the Issue Date (the "Filing Deadline Date")
a Registration Statement for an offering to be made on a delayed or continuous
basis pursuant to Rule 415 of the Securities Act (a "Shelf Registration
Statement") registering the resale from time to time by Holders thereof of all
of the Registrable Securities (the "Initial Shelf Registration Statement"). The
Initial Shelf Registration Statement shall be on Form S-3 or another appropriate
form permitting registration of such Registrable Securities for resale by such
Holders in accordance with the methods of distribution elected by the Holders
and set forth in the Initial Shelf Registration Statement; provided, that in no
event will such method(s) of distribution take the form of an underwritten
offering of the Registrable Securities without the prior agreement of the
Company. The Company shall use reasonable efforts to cause the Initial Shelf
Registration Statement to be declared effective under the Securities Act by the
date (the "Effectiveness Deadline Date") that is one hundred and eighty (180)
days after the Issue Date, and to keep the Initial Shelf Registration Statement
(or any Subsequent Shelf Registration Statement) continuously effective under
the Securities Act until the expiration of the Effectiveness Period, subject to
the rights of the Company under Section 3(h) to create a Deferral Period. At the
time the Initial Shelf Registration Statement is declared effective, each Holder
that became a Notice Holder on or prior to the date ten (10) Business Days prior
to such time of effectiveness shall be named as a selling securityholder in the
Initial Shelf Registration Statement and the related Prospectus in such a manner
as to permit such Holder to deliver such Prospectus to purchasers of Registrable
Securities in accordance with applicable law.

            (b)   If the Initial Shelf Registration Statement or any Subsequent
Shelf Registration Statement ceases to be effective for any reason at any time
during the Effectiveness Period, the Company shall use reasonable efforts to
obtain the prompt withdrawal of any order

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suspending the effectiveness thereof, and in any event shall within thirty (30)
days of such cessation of effectiveness amend the Shelf Registration Statement
in a manner reasonably expected by the Company to obtain the withdrawal of the
order suspending the effectiveness thereof, or file an additional Shelf
Registration Statement covering all of the Securities that as of the date of
such filing are Registrable Securities (a "Subsequent Shelf Registration
Statement"). If a Subsequent Shelf Registration Statement is filed, the Company
shall use reasonable efforts to cause the Subsequent Shelf Registration
Statement to become effective as promptly as is practicable after such filing
and to keep such Registration Statement (or subsequent Shelf Registration
Statement) continuously effective until the end of the Effectiveness Period.

            (c)   The Company shall supplement and amend the Shelf Registration
Statement if required by the rules, regulations or instructions applicable to
the registration form used by the Company for such Shelf Registration Statement
if required by the Securities Act or, to the extent to which the Company does
not reasonably object, as reasonably requested by the Initial Purchaser or by
the Trustee on behalf of the registered Holders.

            (d)   Each Holder of Registrable Securities agrees that if such
Holder wishes to sell Registrable Securities pursuant to a Shelf Registration
Statement and related Prospectus, it will do so only in accordance with this
Section 2(d) and Section 3(h). Each Holder of Registrable Securities wishing to
sell Registrable Securities pursuant to a Shelf Registration Statement and
related Prospectus agrees to deliver a Notice and Questionnaire to the Company
at least eight (8) but not more than twenty (20) Business Days prior to any
intended distribution of Registrable Securities under the Shelf Registration
Statement. From and after the date the Initial Shelf Registration Statement is
declared effective, the Company shall, as promptly as reasonably practicable
after the date a Notice and Questionnaire is delivered, and in any event within
five (5) Business Days after such date, (i) if required by applicable law, file
with the SEC a post-effective amendment to the Shelf Registration Statement or
prepare and, if required by applicable law, file a supplement to the related
Prospectus or a supplement or amendment to any document incorporated therein by
reference or file any other document required by the SEC so that the Holder
delivering such Notice and Questionnaire is named as a selling securityholder in
the Shelf Registration Statement and the related Prospectus in such a manner as
to permit such Holder to deliver such Prospectus to purchasers of the
Registrable Securities in accordance with applicable law and, if the Company
shall file a post-effective amendment to the Shelf Registration Statement, use
reasonable efforts to cause such post-effective amendment to be declared
effective under the Securities Act as promptly as is practicable; (ii) provide
such Holder copies of any documents filed pursuant to Section 2(d)(i); and (iii)
notify such Holder as promptly as practicable after the effectiveness under the
Securities Act of any post-effective amendment filed pursuant to Section
2(d)(i); provided, that if such Notice and Questionnaire is delivered during a
Deferral Period, the Company shall so inform the Holder delivering such Notice
and Questionnaire and shall take the actions set forth in clauses (i), (ii) and
(iii) above upon expiration of the Deferral Period in accordance with Section
3(h). Notwithstanding anything contained herein to the contrary, the Company
shall be under no obligation to name any Holder that is not a Notice Holder as a
selling securityholder in any Registration Statement or related Prospectus;
provided, however, that any Holder that becomes a Notice Holder pursuant to the
provisions of Section 2(d) of this Agreement (whether or not such Holder was a
Notice Holder at the time the Registration Statement was initially declared
effective) shall be named as a selling

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securityholder in the Registration Statement or related Prospectus subject to
and in accordance with the requirements of this Section 2(d).

            (e)   The parties hereto agree that the Holders of Registrable
Securities will suffer damages, and that it would not be feasible to ascertain
the extent of such damages with precision, if (i) the Initial Shelf Registration
Statement has not been filed on or prior to the Filing Deadline Date, (ii) the
Initial Shelf Registration Statement has not been declared effective under the
Securities Act on or prior to the Effectiveness Deadline Date, or (iii) the
aggregate duration of Deferral Periods in any period exceeds the number of days
permitted in respect of such period pursuant to Section 3(h) hereof (each of the
events of a type described in any of the foregoing clauses (i) through (iii) are
individually referred to herein as an "Event," and the Filing Deadline Date in
the case of clause (i), the Effectiveness Deadline Date in the case of clause
(ii), and the date on which the aggregate duration of Deferral Periods in any
period exceeds the number of days permitted by Section 3(h) hereof in the case
of clause (iii), being referred to herein as an "Event Date"). Events shall be
deemed to continue until the "Event Termination Date," which shall be the
following dates with respect to the respective types of Events: the date the
Initial Shelf Registration Statement is filed in the case of an Event of the
type described in clause (i), the date the Initial Shelf Registration Statement
is declared effective under the Securities Act in the case of an Event of the
type described in clause (ii) and termination of the Deferral Period that caused
the limit on the aggregate duration of Deferral Periods in a period set forth in
Section 3(h) to be exceeded in the case of the commencement of an Event of the
type described in clause (iii).

            Accordingly, commencing on (and including) any Event Date and ending
on (but excluding) the next date on which there are no Events that have occurred
and are continuing (a "Damages Accrual Period"), the Company agrees to pay, as
liquidated damages and not as a penalty, an amount (the "Liquidated Damages
Amount"), payable on the Damages Payment Dates to Record Holders of then
outstanding Debentures that are Registrable Securities accruing, for each
portion of such Damages Accrual Period beginning on and including a Damages
Payment Date (or, in respect of the first time that the Liquidation Damages
Amount is to be paid to Record Holders on a Damages Payment Date as a result of
the occurrence of any particular Event, beginning on and including the Event
Date) and ending on but excluding the first to occur of (A) the date of the end
of the Damages Accrual Period or (B) the next Damages Payment Date, at a rate
per annum equal to one-quarter of one percent (0.25%) for the first 90-day
period from the Event Date, and thereafter at a rate per annum equal to one-half
of one percent (0.50%) of the aggregate principal amount of such Debentures
determined as of the Record Date; provided, that any Liquidated Damages Amount
accrued with respect to any Debenture or portion thereof called for redemption
on a redemption date or converted into Underlying Common Stock on a conversion
date prior to the Damages Payment Date, shall, in any such event, be paid
instead to the Holder who submitted such Debenture or portion thereof for
redemption or conversion on the applicable redemption date or conversion date,
as the case may be, on such date (or promptly following the conversion date, in
the case of conversion).

            Notwithstanding the foregoing, no Liquidated Damages Amounts shall
accrue as to any Underlying Common Stock at any time nor as to any Debenture
from and after the earlier of (x) the date such security is no longer a
Registrable Security and (y) expiration of the Effectiveness Period. The rate of
accrual of the Liquidated Damages Amount with respect to any

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period shall not exceed the rate provided for in this paragraph notwithstanding
the occurrence of multiple concurrent Events. Following the cure of all Events
requiring the payment by the Company of Liquidated Damages Amounts to the
Holders of Registrable Securities pursuant to this Section, the accrual of
Liquidated Damages Amounts will cease (without in any way limiting the effect of
any subsequent Event requiring the payment of Liquidated Damages Amount by the
Company).

            The Trustee shall be entitled, on behalf of Holders of Debentures or
Underlying Common Stock, to seek any available remedy for the enforcement of
this Agreement, including, with respect to Debentures, for the payment of any
Liquidated Damages Amount. Notwithstanding the foregoing, the parties agree that
the sole remedy for a violation of the terms of this Agreement shall be such
liquidated damages.

            All of the Company's obligations set forth in this Section 2(e) that
are outstanding with respect to any Registrable Security at the time such
Security ceases to be a Registrable Security shall survive until such time as
all such obligations with respect to such security have been satisfied in full
(notwithstanding termination of this Agreement pursuant to Section 8(j)).

            The parties hereto agree that the liquidated damages provided for in
this Section 2(e) constitute a reasonable estimate of the damages that may be
incurred by Record Holders of then outstanding Debentures that are Registrable
Securities by reason of the failure of the Shelf Registration Statement to be
filed or declared effective or available for effecting resales of Registrable
Securities in accordance with the provisions hereof.

     SECTION 3. REGISTRATION PROCEDURES. In connection with the registration
obligations of the Company under Section 2 hereof, the Company shall:

            (a)   Before filing any Registration Statement or Prospectus or any
amendments or supplements thereto with the SEC, furnish to the Initial Purchaser
copies of all such documents proposed to be filed and give reasonable
consideration to such comments as the Initial Purchaser reasonably shall propose
within three (3) Business Days of the delivery of such copies to the Initial
Purchaser.

            (b)   Subject to Section 3(h), prepare and file with the SEC such
amendments and post-effective amendments to each Registration Statement as may
be necessary to keep such Registration Statement continuously effective for the
applicable period specified in Section 2(a); cause the related Prospectus to be
supplemented by any required Prospectus supplement, and as so supplemented to be
filed pursuant to Rule 424 (or any similar provisions then in force) under the
Securities Act; and use reasonable efforts to comply with the provisions of the
Securities Act applicable to it with respect to the disposition of all
securities covered by such Registration Statement during the Effectiveness
Period in accordance with the intended methods of disposition by the sellers
thereof set forth in such Registration Statement as so amended or such
Prospectus as so supplemented.

            (c)   As promptly as practicable give notice to the Notice Holders
and the Initial Purchaser (i) when any Prospectus, Prospectus supplement,
Registration Statement or post-effective amendment to a Registration Statement
(other than any such Prospectus

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supplement, Registration Statement or post-effective amendment to a Registration
Statement which is filed solely to name additional selling security holders or
to reflect any other matters that are not of a material nature) has been filed
with the SEC and, with respect to a Registration Statement or any post-effective
amendment, when the same has been declared effective, (ii) of any request,
following the effectiveness of the Initial Shelf Registration Statement under
the Securities Act, by the SEC or any other federal or state governmental
authority for amendments or supplements to any Registration Statement or related
Prospectus or for additional information, (iii) of the issuance by the SEC or
any other federal or state governmental authority of any stop order suspending
the effectiveness of any Registration Statement or the initiation or threatening
of any proceedings for that purpose, and (iv) of the receipt by the Company of
any notification with respect to the suspension of the qualification or
exemption from qualification of any of the Registrable Securities for sale in
any jurisdiction or the initiation or threatening of any proceeding for such
purpose, which notice may, at the discretion of the Company (or as required
pursuant to Section 3(h)), state that it constitutes a Deferral Notice, in which
event the provisions of Section 3(h) shall apply.

            (d)   Use all reasonable efforts to obtain the withdrawal of any
order suspending the effectiveness of a Registration Statement or the lifting of
any suspension of the qualification (or exemption from qualification) of any of
the Registrable Securities for sale in any jurisdiction in which they have been
qualified for sale, in either case at the earliest possible moment.

            (e)   As promptly as reasonably practicable furnish to each Notice
Holder and the Initial Purchaser, upon their request and without charge, at
least one (1) conformed copy of the Registration Statement and any amendment
thereto, including financial statements, but excluding schedules, all documents
incorporated or deemed to be incorporated therein by reference and all exhibits
(unless requested in writing to the Company by such Notice Holder or the Initial
Purchaser, as the case may be).

            (f)   During the Effectiveness Period, deliver to each Notice Holder
in connection with any sale of Registrable Securities pursuant to a Registration
Statement, without charge, as many copies of the Prospectus or Prospectuses
relating to such Registrable Securities (including each preliminary prospectus)
and any amendment or supplement thereto as such Notice Holder may reasonably
request; and the Company hereby consents (except during such periods that a
Deferral Notice is outstanding and has not been revoked) to the use of such
Prospectus or each amendment or supplement thereto by each Notice Holder in
connection with any offering and sale of the Registrable Securities covered by
such Prospectus or any amendment or supplement thereto in the manner set forth
therein.

            (g)   Subject to Section 3(h), prior to any public offering of the
Registrable Securities pursuant to the Shelf Registration Statement, use all
reasonable efforts to register or qualify or cooperate with the Notice Holders
in connection with the registration or qualification (or exemption from such
registration or qualification) of such Registrable Securities for offer and sale
under the securities or Blue Sky laws of such jurisdictions within the United
States as any Notice Holder reasonably requests in writing (which request may be
included in the Notice and Questionnaire); prior to any public offering of the
Registrable Securities pursuant to the Shelf Registration Statement, use
reasonable efforts to keep each such registration or qualification (or

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exemption therefrom) effective during the Effectiveness Period in connection
with such Notice Holder's offer and sale of Registrable Securities pursuant to
such registration or qualification (or exemption therefrom) and do any and all
other acts or things necessary to enable the disposition in such jurisdictions
of such Registrable Securities in the manner set forth in the relevant
Registration Statement and the related Prospectus; provided, that the Company
will not be required to (i) qualify as a foreign corporation or as a dealer in
securities in any jurisdiction where it is not otherwise qualified but for this
Agreement or (ii) take any action that would subject it to general service of
process in suits or to taxation in any such jurisdiction where it is not then so
subject.

            (h)   Upon (A) the issuance by the SEC of a stop order suspending
the effectiveness of the Shelf Registration Statement or the initiation of
proceedings with respect to the Shelf Registration Statement under Section 8(d)
or 8(e) of the Securities Act, (B) the occurrence of any event or the existence
of any fact (a "Material Event") as a result of which any Registration Statement
shall contain any untrue statement of a material fact or omit to state any
material fact required to be stated therein or necessary to make the statements
therein not misleading, or any Prospectus shall contain any untrue statement of
a material fact or omit to state any material fact required to be stated therein
or necessary to make the statements therein, in the light of the circumstances
under which they were made, not misleading, or (C) the occurrence or existence
of any pending corporate development that, in the discretion of the Company,
makes it appropriate to suspend the availability of the Shelf Registration
Statement and the related Prospectus, (i) in the case of clause (B) above,
subject to the next sentence, as promptly as practicable prepare and file a
post-effective amendment to such Registration Statement or a supplement to the
related Prospectus or any document incorporated therein by reference or file any
other required document that would be incorporated by reference into such
Registration Statement and Prospectus so that such Registration Statement does
not contain any untrue statement of a material fact or omit to state any
material fact required to be stated therein or necessary to make the statements
therein not misleading, and such Prospectus does not contain any untrue
statement of a material fact or omit to state any material fact required to be
stated therein or necessary to make the statements therein, in the light of the
circumstances under which they were made, not misleading, as thereafter
delivered to the purchasers of the Registrable Securities being sold thereunder,
and, in the case of a post-effective amendment to a Registration Statement,
subject to the next sentence, use reasonable efforts to cause it to be declared
effective as promptly as is reasonably practicable, and (ii) give notice to the
Notice Holders that the availability of the Shelf Registration Statement is
suspended (a "Deferral Notice") and, upon receipt of any Deferral Notice, each
Notice Holder agrees not to sell any Registrable Securities pursuant to the
Registration Statement until such Notice Holder's receipt of copies of the
supplemented or amended Prospectus provided for in clause (i) above, or until it
is advised in writing by the Company that the Prospectus may be used, and has
received copies of any additional or supplemental filings that are incorporated
or deemed incorporated by reference in such Prospectus. The Company will use all
reasonable efforts to ensure that the use of the Prospectus may be resumed (x)
in the case of clause (A) above, as promptly as practicable, (y) in the case of
clause (B) above, as soon as, in the sole judgment of the Company, public
disclosure of such Material Event would not be prejudicial to or contrary to the
interests of the Company or, if necessary to avoid unreasonable burden or
expense, as soon as reasonably practicable thereafter and (z) in the case of
clause (C) above, as soon as, in the sole judgment of the Company, such
suspension is no longer appropriate. The period during which the availability of

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the Registration Statement and any Prospectus is suspended (the "Deferral
Period") shall, without the Company incurring any obligation to pay liquidated
damages pursuant to Section 2(e), not exceed thirty (30) days in any three (3)
month period or ninety (90) days in any twelve (12) month period.

            (i)   Comply with all applicable rules and regulations of the SEC
and make generally available to its securityholders earning statements (which
need not be audited) satisfying the provisions of Section 11(a) of the
Securities Act and Rule 158 thereunder (or any similar rule promulgated under
the Securities Act) no later than forty-five (45) days after the end of any
12-month period (or ninety (90) days after the end of any 12-month period if
such period is a fiscal year) commencing on the first day of the first fiscal
quarter of the Company commencing after the effective date of a Registration
Statement, which statements shall cover said 12-month periods.

            (j)   If reasonably requested in writing by a Holder or Holders of
Registrable Securities and solely at the Company's discretion, the Company will
consider an underwritten offering of Registrable Securities held by such Holder
or Holders upon terms and conditions to be agreed upon at the time of such
underwritten offering.

            (k)   Cooperate with each Notice Holder to facilitate the timely
preparation and delivery of certificates representing Registrable Securities
sold pursuant to a Registration Statement, and cause such Registrable Securities
to be in such denominations as are permitted by the Indenture and registered in
such names as such Notice Holder may request in writing at least two Business
Days prior to any sale of such Registrable Securities.

            (l)   Provide a CUSIP number for all Registrable Securities covered
by each Registration Statement not later than the effective date of such
Registration Statement and provide the Trustee for the Debentures and the
transfer agent for the Common Stock with certificates for the Registrable
Securities that are in a form eligible for deposit with The Depository Trust
Company.

            (m)   Make reasonable effort to provide such information as is
required for any filings required to be made with the National Association of
Securities Dealers, Inc.

            (n)   Upon (i) the filing of the Initial Shelf Registration
Statement and (ii) the effectiveness of the Initial Shelf Registration
Statement, announce the same, in each case by release to Reuters Economic
Services and Bloomberg Business News.; and

            (o)   Cause the Indenture to be qualified under the TIA not later
than the effective date of any Registration Statement; and in connection
therewith, cooperate with the Trustee to effect such changes to the Indenture as
may be required for the Indenture to be so qualified in accordance with the
terms of the TIA and execute, and use reasonable efforts to cause the Trustee to
execute, all documents as may be required to effect such changes, and all other
forms and documents required to be filed with the SEC to enable the Indenture to
be so qualified in a timely manner.

     SECTION 4. HOLDER'S OBLIGATIONS. Each Holder agrees, by acquisition of the
Registrable Securities, that no Holder of Registrable Securities shall be
entitled to sell any of

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such Registrable Securities pursuant to a Registration Statement or to receive a
Prospectus relating thereto, unless such Holder has furnished the Company with a
Notice and Questionnaire as required pursuant to Section 2(d) hereof (including
the information required to be included in such Notice and Questionnaire) and
the information set forth in the next sentence. Each Notice Holder agrees
promptly to furnish to the Company all information required to be disclosed in
order to make the information previously furnished to the Company by such Notice
Holder not misleading and any other information regarding such Notice Holder and
the distribution of such Registrable Securities as may be required to be
disclosed in the Registration Statement under applicable law or pursuant to SEC
comments. Each Holder further agrees, following termination of the Effective
Period, to notify the Company within ten (10) Business Days of request, of the
amount of Registrable Securities sold pursuant to the Registration Statement
and, in the absence of a response, the Company may assume that all of the
Holder's Registrable Securities were so sold.

     SECTION 5. REGISTRATION EXPENSES. The Company shall bear all fees and
expenses incurred in connection with the performance by the Company of its
obligations under Sections 2 and 3 of this Agreement whether or not any of the
Registration Statements are declared effective. Such fees and expenses shall
include, without limitation, (i) all registration and filing fees (including,
without limitation, reasonable fees and disbursements of the counsel specified
in the next sentence in connection with Blue Sky qualifications of the
Registrable Securities under the laws of such jurisdictions as the Notice
Holders of a majority of the Registrable Securities being sold pursuant to a
Registration Statement may designate), (ii) printing expenses (including,
without limitation, expenses of printing certificates for Registrable Securities
in a form eligible for deposit with The Depository Trust Company), (iii)
duplication expenses relating to copies of any Registration Statement or
Prospectus delivered to any Holders hereunder, (iv) fees and disbursements of
counsel for the Company in connection with the Shelf Registration Statement, and
(v) reasonable fees and disbursements of the Trustee and its counsel and of the
registrar and transfer agent for the Common Stock. In addition, the Company
shall bear or reimburse the Notice Holders for the reasonable fees and
disbursements of one firm of legal counsel for the Holders incurred in reviewing
and commenting upon the Shelf Registration Statement prior to its effectiveness,
which shall, upon the written consent of the Initial Purchaser (which shall not
be unreasonably withheld), be a nationally recognized law firm experienced in
securities law matters designated by the Company. In addition, the Company shall
pay the internal expenses of the Company (including, without limitation, all
salaries and expenses of officers and employees performing legal or accounting
duties), the expense of any annual audit, the fees and expenses incurred in
connection with the listing of the Registrable Securities on any securities
exchange on which the same securities of the Company are then listed and the
fees and expenses of any person, including special experts, retained by the
Company.

     SECTION 6. INDEMNIFICATION; CONTRIBUTION.

            (a)   The Company agrees to indemnify and hold harmless the Initial
Purchaser and each Holder of Registrable Securities and each person, if any, who
controls the Initial Purchaser or any Holder of Registrable Securities within
the meaning of either Section 15 of the Securities Act or Section 20 of the
Exchange Act, as follows:

                                       11
<Page>

            (i)   against any and all loss, liability, claim, damage and expense
     whatsoever, as incurred, resulting from any untrue statement or alleged
     untrue statement of a material fact contained in the Registration Statement
     (or any amendment thereto), or the omission or alleged omission therefrom
     of a material fact necessary in order to make the statements therein, in
     light of the circumstances under which they were made, not misleading or
     resulting from any untrue statement or alleged untrue statement of a
     material fact included in any preliminary prospectus or the Prospectus (or
     any amendment or supplement thereto), or the omission or alleged omission
     therefrom of a material fact necessary in order to make the statements
     therein, in the light of the circumstances under which they were made, not
     misleading;

            (ii)  against any and all loss, liability, claim, damage and expense
     whatsoever, as incurred, to the extent of the aggregate amount paid in
     settlement of any litigation, or any investigation or proceeding by any
     governmental agency or body, commenced or threatened, or of any claim
     whatsoever based upon any such untrue statement or omission, or any such
     alleged untrue statement or omission, provided that (subject to Section
     6(d) below) any such settlement is effected with the prior written consent
     of the Company; and

            (iii) subject to Section 6(c) below, against any and all expense
     whatsoever, as incurred (including the fees and disbursements of counsel),
     reasonably incurred in investigating, preparing or defending against any
     litigation, or any investigation or proceeding by any governmental agency
     or body, commenced or threatened, or any claim whatsoever based upon any
     such untrue statement or omission, or any such alleged untrue statement or
     omission, to the extent that any such expense is not paid under (i) or (ii)
     above;

provided, however, that this indemnity agreement shall not apply to any loss,
liability, claim, damage or expense to the extent arising out of any untrue
statement or omission or alleged untrue statement or omission made in reliance
upon and in conformity with written information furnished to the Company by or
on behalf of the Initial Purchaser or any Holder of Registrable Securities and
each person, if any, who controls the Initial Purchaser or any such Holder of
Registrable Securities expressly for use in the Registration Statement (or any
amendment thereto), or any preliminary prospectus or the Prospectus (or any
amendment or supplement thereto); provided, further, that this indemnity
agreement shall not apply to any loss, liability, claim, damage or expense (1)
arising from an offer or sale of Registrable Securities occurring during a
Deferral Period, if a Notice Holder was given a Deferral Notice, or (2) a Holder
fails to deliver at or prior to the written confirmation of sale, the most
recent Prospectus, as amended or supplemented, and such Prospectus, as amended
or supplemented, would have corrected such untrue statement or alleged untrue
statement of a material fact or would have included the omitted or allegedly
omitted statement of a material fact.

            (b)   In connection with any Shelf Registration in which a Holder,
including, without limitation, the Initial Purchaser, of Registrable Securities
is participating, in furnishing information relating to such Holder of
Registrable Securities to the Company in writing expressly for use in such
Registration Statement, any preliminary prospectus, the Prospectus or

                                       12
<Page>

any amendments or supplements thereto, the Holders of such Registrable
Securities agree, severally and not jointly, to indemnify and hold harmless the
Initial Purchaser and each person, if any, who controls the Initial Purchaser
within the meaning of either Section 15 of the Securities Act or Section 20 of
the Exchange Act and the Company, and each person, if any, who controls the
Company within the meaning of either such Section, against any and all loss,
liability, claim, damage and expense described in the indemnity contained in
subsection (a) of this Section, as incurred, but only with respect to untrue
statements or omissions, or alleged untrue statements or omissions, made in the
Registration Statement (or any amendment thereto), or any preliminary prospectus
or the Prospectus (or any amendment or supplement thereto) in reliance upon and
in conformity with written information furnished to the Company by or on behalf
of such Holder of Registrable Securities (which also acknowledges the indemnity
provisions herein) or any person, if any, who controls any such Holder of
Registrable Securities expressly for use in the Registration Statement (or any
amendment thereto) or such preliminary prospectus or the Prospectus (or any
amendment or supplement thereto).

            The Initial Purchaser agrees to indemnify and hold harmless the
Company, the Holders of Registrable Securities, and each person, if any, who
controls the Company or any Holder of Registrable Securities within the meaning
of either Section 15 of the Securities Act or Section 20 of the Exchange Act
against any and all loss, liability, claim, damage and expense described in the
indemnity contained in subsection (a) of this Section, as incurred, but only
with respect to untrue statements or omissions, or alleged untrue statements or
omissions, made in the Registration Statement (or any amendment thereto), or any
preliminary prospectus or the Prospectus (or any amendment or supplement
thereto) in reliance upon and in conformity with written information furnished
to the Company by or on behalf of the Initial Purchaser expressly for use in the
Registration Statement (or any amendment thereto) or such preliminary prospectus
or the Prospectus (or any amendment or supplement thereto).

            (c)   Each indemnified party shall give notice as promptly as
reasonably practicable to each indemnifying party of any action commenced
against it in respect of which indemnity may be sought hereunder, but failure to
so notify an indemnifying party shall not relieve such indemnifying party from
any liability hereunder to the extent it is not materially prejudiced as a
result thereof and in any event shall not relieve it from any liability which it
may have otherwise than on account of this indemnity agreement. The indemnifying
party, upon request of the indemnified party, shall retain counsel reasonably
satisfactory to the indemnified party to represent the indemnified party and any
others the indemnifying party may designate in such proceeding and shall pay the
fees and disbursements of such counsel related to such proceeding. In any such
proceeding, any indemnified party shall have the right to retain its own
counsel, but the fees and expenses of such counsel shall be at the expense of
such indemnified party unless (i) the indemnifying party and the indemnified
party shall have mutually agreed to the retention of such counsel or (ii) the
named parties to any such proceeding (including any impleaded parties) include
both the indemnifying party and the indemnified party and representation of both
parties by the same counsel would be inappropriate due to actual or potential
differing interests between them. It is understood that the indemnifying party
shall not, in respect of the legal expenses of any indemnified party in
connection with any proceeding or related proceedings in the same jurisdiction,
be liable for (a) the fees and expenses of more than one separate firm (in
addition to any local counsel) for the Initial Purchaser, Holders of Registrable
Securities, and all persons, if any, who control the Initial Purchaser or
Holders of

                                       13
<Page>

Registrable Securities within the meaning of either Section 15 of the Securities
Act or Section 20 of the Exchange Act, collectively (b) the fees and expenses of
more than one separate firm (in addition to any local counsel) for the Company,
its directors, and each person, if any, who controls the Company within the
meaning of either such Section, and that all such fees and expenses shall be
reimbursed as they are incurred. In the case of any such separate firm for the
Initial Purchaser, Holders of Registrable Securities, and control persons of the
Initial Purchaser and Holders of Registrable Securities, such firm shall be
designated in writing by the Initial Purchaser. In the case of any such separate
firm for the Company, and such directors, officers and control persons of the
Company, such firm shall be designated in writing by the Company. The
indemnifying party shall not be liable for any settlement of any proceeding
effected without its written consent, but if settled with such consent or if
there be a final judgment for the plaintiff, the indemnifying party agrees to
indemnify the indemnified party from and against any loss or liability by reason
of such settlement or judgment. Notwithstanding the foregoing sentence, if at
any time an indemnified party shall have requested an indemnifying party to
reimburse the indemnified party for fees and expenses of counsel as contemplated
by the second and third sentences of this paragraph, the indemnifying party
agrees that it shall be liable for any settlement of any proceeding effected
without its written consent if (i) such settlement is entered into more than
forty-five (45) days after receipt by such indemnifying party of the aforesaid
request, (ii) such indemnifying party shall have received notice of the terms of
such settlement at least thirty (30) days prior to such settlement being entered
into and (iii) such indemnifying party shall not have reimbursed the indemnified
party in accordance with such request prior to the date of such settlement.
Notwithstanding the immediately preceding sentence, if at any time an
indemnified party shall have requested an indemnifying party to reimburse the
indemnified party for fees and expenses of counsel, an indemnifying party shall
not be liable for any settlement effected without its consent if such
indemnifying party (i) reimburses such indemnified party in accordance with such
request to the extent it considers such request to be reasonable and (ii)
provides written notice to the indemnified party substantiating the unpaid
balance as unreasonable, in each case prior to the date of such settlement. No
indemnifying party shall, without the prior written consent of the indemnified
parties, settle or compromise or consent to the entry of any judgment with
respect to any litigation, or any investigation or proceeding by any
governmental agency or body, commenced or threatened, or any claim whatsoever in
respect of which indemnification or contribution could be sought under this
Section 6 (whether or not the indemnified parties are actual or potential
parties thereto), unless such settlement, compromise or consent (i) includes an
unconditional release of each indemnified party from all liability arising out
of such litigation, investigation, proceeding or claim and (ii) does not include
a statement as to or an admission of fault, culpability or a failure to act by
or on behalf of any indemnified party.

            (d)   If at any time an indemnified party shall have requested an
indemnifying party to reimburse the indemnified party for fees and expenses of
counsel, such indemnifying party agrees that it shall be liable for any
settlement of the nature contemplated by Section 6(a)(ii) effected without its
written consent if (i) such settlement is entered into more than forty-five (45)
days after receipt by such indemnifying party of aforesaid request, (ii) such
indemnifying party shall have received notice of the terms of such settlement at
least thirty (30) days prior to such settlement being entered into and (iii)
such indemnifying party shall not have reimbursed such indemnified party in
accordance with such request prior to the date of such settlement.
Notwithstanding the immediately preceding sentence, if at any time an
indemnified

                                       14
<Page>

party shall have requested an indemnifying party to reimburse the indemnified
party for fees and expenses of counsel, an indemnifying party shall not be
liable for any settlement of the nature contemplated by Section 6(a)(ii)
effected without its consent if such indemnifying party (1) reimburses such
indemnified party in accordance with such request to the extent it considers
such request to be reasonable and (2) provides written notice to the indemnified
party substantiating the unpaid balance as unreasonable, in each case prior to
the date of such settlement.

            (e)   If the indemnification provided for in this Section 6 is for
any reason unavailable to or insufficient to hold harmless an indemnified party
in respect of any losses, liabilities, claims, damages or expenses referred to
therein, then each indemnifying party shall contribute to the aggregate amount
of such losses, liabilities, claims, damages and expenses incurred by such
indemnified party, as incurred, in such proportion as is appropriate to reflect
the relative fault of the indemnifying party or parties on the one hand and of
the indemnified party on the other hand in connection with the statements or
omissions which resulted in such losses, liabilities, claims, damages or
expenses, as well as any other relevant equitable considerations.

            The relative fault of the Company on the one hand and the Holders of
the Registrable Securities or the Initial Purchaser on the other hand shall be
determined by reference to, among other things, whether any such untrue or
alleged untrue statement of a material fact or omission or alleged omission to
state a material fact relates to information supplied by the Company or by the
Holders of the Registrable Securities or the Initial Purchaser and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such statement or omission.

            The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 6(e) were determined by pro rata
allocation or by any other method of allocation which does not take account of
the equitable considerations referred to above in this Section 6(e). The
aggregate amount of losses, liabilities, claims, damages, and expenses incurred
by an indemnified party and referred to above in this Section 6(e) shall be
deemed to include any legal or other expenses reasonably incurred by such
indemnified party in investigating, preparing or defending against any
litigation, or any investigation or proceeding by any governmental agency or
body, commenced or threatened, or any claim whatsoever based upon any such
untrue or alleged untrue statement or omission or alleged omission.

            Notwithstanding the provisions of this Section 6, neither the Holder
of any Registrable Securities nor the Initial Purchaser, shall be required to
indemnify or contribute any amount in excess of the amount by which the total
price at which the Registrable Securities sold by such Holder of Registrable
Securities or by the Initial Purchaser, as the case may be, and distributed to
the public were offered to the public exceeds the amount of any damages that
such Holder of Registrable Securities or the Initial Purchaser has otherwise
been required to pay by reason of such untrue or alleged untrue statement or
omission or alleged omission.

            No person guilty of fraudulent misrepresentation (within the meaning
of Section 11(f) of the Securities Act) shall be entitled to contribution from
any person who was not guilty of such fraudulent misrepresentation.

                                       15
<Page>

            For purposes of this Section 6(e), each person, if any, who controls
the Initial Purchaser or any Holder of Registrable Securities within the meaning
of Section 15 of the Securities Act or Section 20 of the Exchange Act shall have
the same rights to contribution as the Initial Purchaser or such Holder, and
each person, if any, who controls the Company within the meaning of Section 15
of the Securities Act or Section 20 of the Exchange Act shall have the same
rights to contribution as the Company.

     SECTION 7. INFORMATION REQUIREMENTS. The Company covenants that, if at any
time before the end of the Effectiveness Period the Company is not subject to
the reporting requirements of the Exchange Act, the Company will cooperate with
any Holder of Registrable Securities and take such further reasonable action as
any Holder of Registrable Securities may reasonably request in writing
(including, without limitation, making such reasonable representations as any
such Holder may reasonably request), all to the extent required from time to
time to enable such Holder to sell Registrable Securities without registration
under the Securities Act within the limitation of the exemptions provided by
Rule 144 and Rule 144A under the Securities Act and customarily taken in
connection with sales pursuant to such exemptions; provided, however, that any
legal opinion required by any trustee or transfer agent shall be the
responsibility of such Holder. Upon the written request of any Holder of
Registrable Securities, the Company shall deliver to such Holder a written
statement as to whether it has complied with such filing requirements, unless
such a statement has been included in the Company's most recent report required
to be filed and filed pursuant to Section 13 or Section 15(d) of Exchange Act.
Notwithstanding the foregoing, nothing in this Section 7 shall be deemed to
require the Company to register any of its securities under any section of the
Exchange Act.

     SECTION 8. MISCELLANEOUS; NO CONFLICTING AGREEMENTS. The Company is not, as
of the date hereof, a party to, nor shall the Company, on or after the date of
this Agreement, enter into any agreement with respect to its securities that
conflicts with the rights granted to the Holders of Registrable Securities in
this Agreement. The Company represents and warrants that the rights granted to
the Holders of Registrable Securities hereunder do not conflict in any material
respect with the rights granted to the holders of the Company securities under
any other agreements.

            (a)   AMENDMENTS AND WAIVERS. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given, unless the Company has obtained the written consent of Holders
of a majority of the then outstanding Underlying Common Stock constituting
Registrable Securities (with Holders of Debentures deemed to be the Holders, for
purposes of this Section, of the number of outstanding shares of Underlying
Common Stock into which such Debentures are or would be convertible or
exchangeable as of the date on which such consent is requested). Notwithstanding
the foregoing, a waiver or consent to depart from the provisions hereof with
respect to a matter that relates exclusively to the rights of Holders of
Registrable Securities whose securities are being sold pursuant to a
Registration Statement and that does not directly or indirectly affect the
rights of other Holders of Registrable Securities may be given by Holders of at
least a majority of the Registrable Securities being sold by such Holders
pursuant to such Registration Statement; provided, that the provisions of this
sentence may not be amended, modified, or supplemented except in accordance with
the provisions of the immediately preceding sentence. Each Holder of

                                       16
<Page>

Registrable Securities outstanding at the time of any such amendment,
modification, supplement, waiver or consent or thereafter shall be bound by any
such amendment, modification, supplement, waiver or consent effected pursuant to
this Section 8(a), whether or not any notice, writing or marking indicating such
amendment, modification, supplement, waiver or consent appears on the
Registrable Securities or is delivered to such Holder.

            (b)   NOTICES. All notices and other communications provided for or
permitted hereunder shall be made in writing by hand delivery, by telecopier, by
courier guaranteeing overnight delivery or by first-class mail, return receipt
requested, and shall be deemed given (i) when made, if made by hand delivery,
(ii) upon confirmation, if made by telecopier, (iii) one (1) Business Day after
being deposited with such courier, if made by overnight courier or (iv) on the
date indicated on the notice of receipt, if made by first-class mail, to the
parties as follows:

            (w)   if to a Holder of Registrable Securities that is not a Notice
Holder, at the address for such Holder then appearing in the Registrar (as
defined in the Indenture);

            (x)   if to a Notice Holder, at the most current address given by
such Holder to the Company in a Notice and Questionnaire or any amendment
thereto;

            (y)   if to the Company, to:

                  Affiliated Managers Group, Inc.
                  600 Hale Street
                  Prides Crossing, MA  01965
                  Attention:  Treasurer
                  Telecopier No.: (617) 747-3380

                  with a copy to:

                  Goodwin Procter LLP
                  Exchange Place
                  Boston, MA  02109
                  Attention:  Martin Carmichael III
                  Telecopier No.: (617) 523-1231

                  and

            (z)   if to the Initial Purchaser, to:

                  Merrill Lynch & Co.,
                  Merrill Lynch, Pierce, Fenner & Smith
                             Incorporated
                  4 World Financial Center
                  New York, New York  10080
                  Attention:  Paul A. Pepe
                  Telecopy No.: (212) 449-6714

                                       17
<Page>

or to such other address as such person may have furnished to the other persons
identified in this Section 8(c) in writing in accordance herewith.

            (c)   APPROVAL OF HOLDERS. Whenever the consent or approval of
Holders of a specified percentage of Registrable Securities is required
hereunder, Registrable Securities held by the Company or its affiliates (as such
term is defined in Rule 405 under the Securities Act) (other than the Initial
Purchaser or subsequent Holders of Registrable Securities if such subsequent
Holders are deemed to be such affiliates solely by reason of their holdings of
such Registrable Securities) shall not be counted in determining whether such
consent or approval was given by the Holders of such required percentage.

            (d)   SUCCESSORS AND ASSIGNS. Any person who purchases any
Registrable Securities from the Initial Purchaser shall be deemed, for purposes
of this Agreement, to be an assignee of the Initial Purchaser. This Agreement
shall inure to the benefit of and be binding upon the successors and assigns of
each of the parties and shall inure to the benefit of and be binding upon each
Holder of any Registrable Securities.

            (e)   COUNTERPARTS. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be original and all of which taken together
shall constitute one and the same agreement.

            (f)   HEADINGS. The headings in this Agreement are for convenience
of reference only and shall not limit or otherwise affect the meaning hereof.

            (g)   GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

            (h)   SEVERABILITY. If any term, provision, covenant or restriction
of this Agreement is held to be invalid, illegal, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions set forth herein
shall remain in full force and effect and shall in no way be affected, impaired
or invalidated thereby, and the parties hereto shall use their best efforts to
find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by such term, provision, covenant or
restriction, it being intended that all of the rights and privileges of the
parties shall be enforceable to the fullest extent permitted by law.

            (i)   ENTIRE AGREEMENT. This Agreement is intended by the parties as
a final expression of their agreement and is intended to be a complete and
exclusive statement of the agreement and understanding of the parties hereto in
respect of the subject matter contained herein and the registration rights
granted by the Company with respect to the Registrable Securities. Except as
provided in the Purchase Agreement, there are no restrictions, promises,
warranties or undertakings, other than those set forth or referred to herein,
with respect to the registration rights granted by the Company with respect to
the Registrable Securities. This Agreement supersedes all prior agreements and
undertakings among the parties solely with respect to such registration rights.

                                       18
<Page>

            (j)   TERMINATION. This Agreement and the obligations of the parties
hereunder shall terminate upon the end of the Effectiveness Period, except for
any liabilities or obligations under Sections 4, 5 or 6 hereof and the
obligations to make payments of and provide for Liquidated Damages under Section
2(e) hereof to the extent such damages accrue prior to the end of the
Effectiveness Period, each of which shall remain in effect in accordance with
its terms.

                                       19
<Page>

            IN WITNESS WHEREOF, the parties have executed this Registration
Rights Agreement as of the date first written above.

                                           AFFILIATED MANAGERS GROUP, INC.


                                           By:  /s/ Darrell W. Crate
                                                --------------------------------
                                                Darrell W. Crate
                                                Executive Vice President and
                                                Chief Financial Officer

Accepted as of the date
first above written:

MERRILL LYNCH & CO.
MERRILL LYNCH, PIERCE, FENNER & SMITH
           INCORPORATED

By: /s/ John Erickson
    -----------------------------------
           Authorized Signatory