<PAGE>   1

                                                                   EXHIBIT 10.51

                              EMPLOYMENT AGREEMENT

         This Employment Agreement is made and entered into as of the fourth
day of November, 1996 between A I M Management Group Inc., a Delaware
corporation (the "Company"), INVESCO PLC, a public company incorporated under
the laws of England, to be known as AMVESCO PLC following the Merger, as
defined below ("INVESCO"), and Robert H. Graham, a resident of Texas ("Global
Partner").

         WHEREAS, the Company desires to employ Global Partner in accordance
with the terms and conditions hereinafter set forth, and Global Partner desires
to accept employment with the Company on the terms and conditions hereinafter
set forth;

         WHEREAS, pursuant to the Agreement and Plan of Merger among the
Company, INVESCO and INVESCO Group Services Inc., dated as of November 4, 1996
(the "Merger Agreement"), the Company proposes to become a member of a group of
related companies (collectively, the "AMVESCO Group") effective upon a business
combination between INVESCO and the Company through a merger of the Company
into and with a wholly-owned subsidiary of INVESCO (the "Merger");

         WHEREAS, a condition precedent to the Merger is that Global Partner
enter into this Employment Agreement;

         WHEREAS, Global Partner acknowledges that the proprietary customer,
operations, investment, investment technique, financial and business
information that has been learned and will be learned about the business of the
Company and/or the AMVESCO Group could be used to harm the interests of the
Company and/or the AMVESCO Group or compete unfairly with the Company and/or
the AMVESCO Group and could also be of great value to the competitors of the
Company and/or the AMVESCO Group; and

         WHEREAS, Global Partner further acknowledges that such proprietary
customer, operations, investment, investment technique, financial and business
information has been developed and will be developed during the course of
Global Partner's employment with the Company through the expenditure by the
Company or other entities in the AMVESCO Group of substantial effort, time and
money.

         NOW, THEREFORE, for and in consideration of the mutual covenants and
agreements hereinafter set forth and other good and valuable consideration, the
receipt, adequacy and sufficiency of which are hereby acknowledged, the parties
hereto covenant and agree as follows:

         1.      Employment and Duties. (a) Commencing at the effective time of
the Merger (the "Commencement Date"), INVESCO agrees to employ Global Partner
as Chief
<PAGE>   2
Executive Officer of the Individual Services Group of INVESCO, which is the
division of INVESCO including the North American mutual fund businesses and
operations of the Company and those other businesses and operations described
in Appendix B-Part II (the "ISG"), and Executive Vice President of INVESCO and
to appoint Global Partner as a director of the Company; and the Company agrees
to employ Global Partner as its Chief Executive Officer (the "Employment").
During the term of this Agreement, Global Partner agrees to be a full-time
employee of the Company and INVESCO and to devote full time, energy and skill
to the business of the Company and the AMVESCO Group.  Global Partner shall
have the authority to (i) hire and fire employees of constituent companies of
the ISG, subject to approval of the Chief Executive Officer of INVESCO for
hires of individuals whose total annual base salary and annual guaranteed bonus
is expected to be the equivalent of $500,000; and (ii) set the amount of the
compensation of all employees of the ISG other than himself, subject to the
approval by the Chief Executive Officer of INVESCO of the size of the total
annual and any long-term incentive bonus pool and of each individual payment
within the pool to an employee which, when aggregated with all other cash
elements of such employee's anticipated annual compensation, is expected to be
the equivalent of $1.2 million.  Global Partner shall advise and consult with
the Chief Executive Officer of INVESCO from time to time and shall exercise his
authority hereunder in a manner consistent with the overall compensation
policies and then current business plan of INVESCO established by the Board of
Directors of INVESCO.  Global Partner acknowledges and agrees that the INVESCO
Designees (within the meaning of the Voting Agreement (as defined in Exhibit B,
Part I)) shall have the right to appoint two officers of INVESCO to serve on
the ISG Management Committee who may be employees of a division or subsidiary
of INVESCO that is not part of the ISG.  INVESCO agrees that total compensation
levels of the ISG employees in relation to gross revenues of constituent
companies of the ISG and bonus levels of such employees in relation to EBITDA
of constituent companies of the ISG on the order of magnitude paid by such
constituent companies and their subsidiaries in the past five years are
acceptable to INVESCO and may be expected to continue in the future.

         (b)     Notwithstanding Global Partner's full time Employment, Global
Partner may participate in industry groups such as the ICI and may engage in
personal investment activity (either alone or together with the other Senior
AIM Executives (as defined in Exhibit B. Part I)), charitable work, and,
subject to the prior written approval of the Board of Directors of INVESCO,
other business activity.  Global Partner will not, however, engage in any
business or activity that is competitive with the activity of the Company or
the AMVESCO Group, or will result in any violation of those of the Company's
policies that have been communicated in writing to Global Partner or in a
conflict of interest with the Company and the business of the Company and the
AMVESCO Group or with the duties of the AMVESCO Group to its clients, or
materially affect Global Partner's ability to perform his or her duties under
this Agreement.





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         2.      Compensation and Benefits.  Global Partner shall be entitled
during the term of his Employment to the compensation and benefits set forth at
Exhibit A--Part I to this Agreement.  Exhibit A may be amended from time to
time, such amended or replacement Exhibit A to take effect when signed by the
Company, INVESCO and Global Partner.

         3.      Place of Employment.  Global Partner's place of employment
shall be with the Company in Houston, Texas (except for ordinary business
related travel outside of such area).

         4.       Termination of Employment. (a) By the Company without Cause
or By Global Partner on Notice.  Except as provided in this Section and except
as may be agreed to in writing by the parties hereto, (i) Global Partner's
Employment may be terminated by the Company and INVESCO for any reason at any
time prior to the fourth anniversary of the Commencement Date (the "Fourth
Anniversary") effective immediately upon sending notice of such termination by
the Company to Global Partner and (ii) on or after the Fourth Anniversary,
Global Partner's Employment may be terminated by the Company, INVESCO or Global
Partner for any reason effective as of a date one year after receipt of notice
of such termination by the other parties, it being understood that the Company,
INVESCO or Global Partner may deliver such one year's notice of termination
under clause (ii) hereof at any time following the third anniversary of the
Commencement Date.

         (b)     By the Company with Cause.  Subject to Section 4(h) hereof in
the case of a termination pursuant to the following clause (i), the Company and
INVESCO may terminate Global Partner's Employment under this Agreement
immediately by notice in writing if at any time during the term of this
Agreement, Global Partner: (i) shall be in continuing material breach, which is
not cured within 30 days of receipt by Global Partner of written notice thereof
from the Chief Executive Officer of INVESCO, of any material term of this
Agreement or the written policies or procedures of the Company or the AMVESCO
Group which are applicable to and made known to Global Partner in writing and
which are required by law or established to maintain compliance with applicable
law or the Code of Ethics applicable to the ISG; (ii) shall be guilty of or any
act of fraud, dishonesty, embezzlement, theft, misappropriation or similar
conduct or other financial crime against the AMVESCO Group or any of its
constituent companies or any client of the AMVESCO Group (other then arising by
an inadvertent error in connection with an expense reimbursement by Global
Partner); (iii) shall be convicted of any felony or shall enter a plea of nolo
contendere to a felony; or (iv) shall engage in any act or omission which
substantially or materially violates the requirements or prohibitions of any
securities law or any governmental entity or agency which is not cured within
30 days of receipt by Global Partner of written notice thereof from the Chief
Executive Officer of INVESCO; provided that any such notice shall be delivered
to Global Partner not more than 60 days after an executive officer of INVESCO
(other than Global Partner) first knows of the occurrence of such event.





                                       3
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         (c)     By Global Partner for Good Reason.  Subject to Section 4(h)
hereof, Global Partner may terminate his Employment hereunder prior to the
Fourth Anniversary for Good Reason which is defined in Exhibit B, Part I to
this Agreement.

         (d)     Termination of Employment Because of Death or Disability.
Global Partner's Employment shall be terminated as a result of his or her death
or, immediately on notice by the Company to such effect, his or her physical or
mental disability due to accident or illness which prevents Global Partner for
a period of six consecutive months, from performing the essential duties of the
position he holds at that time with reasonable accommodation as determined by
INVESCO, based on the advice of a mutually acceptable physician.

         (e)     Payments and Obligations on Termination.  In the event of a
termination of Global Partner's Employment effective at any time prior to the
Fourth Anniversary by the Company or INVESCO, other than pursuant to Section
4(b) or 4(d), or in the event of termination of Global Partner's Employment
effective at any time prior to the Fourth Anniversary by Global Partner
pursuant to Section 4(c), Global Partner shall be entitled to receive continued
payments of his minimum salary and bonus as specified in Exhibit A, Part II
until the later of the Fourth Anniversary or the first anniversary of
termination of Employment and all other obligations of the Company and INVESCO
hereunder (other than those in Section 4(f)) shall terminate immediately.
Global Partner shall be under no obligation to accept any employment during the
period for which Global Partner receives such continued salary and bonus
payments hereunder or to otherwise attempt to mitigate the payment of such
amounts by the Company and the Company and INVESCO waive any right to allege
that Global Partner has any duty to mitigate the payment of such amounts.  In
the event of a termination of Employment pursuant to Section 4(d), Global
Partner (or his or her estate) shall be entitled to receive his or her minimum
salary as set forth in Exhibit A, Part II for a period of three months
following such termination and all other obligations of the Company hereunder
(other than those in Section 4(f)) shall terminate immediately.  In the event
of any other termination of Employment, all obligations of the Company and
INVESCO (other than those in Section 4(f)) shall immediately terminate on the
effective date of such termination.  In the event of any termination of
Employment (other than due to the death of Global Partner), the obligations of
Global Partner under Sections 5, 6, 7, 8 and 9 hereof shall continue in full
force and effect for the period specified in each such Section.  In the event
of a termination of the Employment by Global Partner for Good Reason pursuant
to Section 4(c), the Global Partner shall have the right to terminate all (but
not less than all) of his rights and obligations under the Voting Agreement as
of the effective date of such termination of Global Partner's employment, such
right to expire if not exercised within 60 days following the effective date of
such termination of employment.

         (f)     Other Payments.  Any unpaid salary that has accrued through
the date on which Employment is terminated will be paid to Global Partner upon
the termination date or,





                                       4
<PAGE>   5
if Global Partner has given notice of such termination, on the next regular pay
date.  Any unpaid bonuses which were awarded prior to the date of termination
of Employment will be paid within a reasonable time.  In the event of any
termination of Global Partner's Employment pursuant to Section 4(a), Section
4(c) or Section 4(d), any unpaid deferred bonuses which were awarded prior to
the date of termination of Employment will be paid within a reasonable time.
In the event of a termination under Section 4(d) disability or death benefits
paid under any insurance plan which may be maintained by the Company or INVESCO
for Global Partner will be paid to Global Partner or his estate.  Following a
notice of termination of Employment, the parties may, but are not obligated to,
enter into an agreement establishing transition compensation and employee
obligations which differ from those provided by this Agreement.

         (g)     Options. This Agreement does not pertain to or modify any
option plan or option agreement.

         (h)     Certain Procedures.

         (i)     Termination by Global Partner.  In the event that Global 
Partner asserts that he has the right to terminate the Employment for Good 
Reason pursuant to Section 4(c), the following procedures shall apply:

                 (A)      Global Partner will deliver written notice thereof to
                 the Company and to INVESCO, Attention: Chief Executive
                 Officer, setting forth in reasonable detail the facts and
                 circumstances Global Partner believes provide the basis for
                 such termination.

                 (B)      Such notice will constitute a request by Global
                 Partner that an arbitration proceeding be initiated pursuant
                 to Section 9(b) of this Agreement to determine whether, in
                 fact, Global Partner has the right to terminate the Employment
                 for Good Reason.

                 (C)      Notwithstanding any other provision of this Agreement
                 or any Exhibit hereto, until the entry of a final judgment by
                 a court of competent jurisdiction as contemplated by Section
                 9(b) confirming that Global Partner, in fact, has the right to
                 terminate the Employment for Good Reason, the parties hereto
                 acknowledge and agree that Global Partner's Employment shall
                 not be deemed terminated pursuant to Section 4(a) or 4(c).

                 (ii)     Termination by the Company and/or INVESCO.  In the
         event that the Company and/or INVESCO asserts that it has the right to
         terminate the Employment for Cause pursuant to clause (i) of Section
         4(b), the following procedures shall apply:





                                       5
<PAGE>   6
                 (A)      The Company and/or INVESCO, as the case may be, will
                 deliver written notice thereof to Global Partner, setting
                 forth in reasonable detail the facts and circumstances the
                 Company and/or INVESCO believes provide the basis for such
                 termination.

                 (B)      Such notice will constitute a request by the Company
                 and/or INVESCO that an arbitration proceeding be initiated
                 pursuant to Section 9(b) of this Agreement to determine
                 whether, in fact, the Company and/or INVESCO has the right to
                 terminate the Employment for Cause.

                 (C)      Notwithstanding any other provision of this Agreement
                 or any Exhibit hereto, until the entry of a final judgment by
                 a court of competent jurisdiction as contemplated by Section
                 9(b) confirming that the Company and/or INVESCO, in fact, has
                 the right to terminate the Employment for Cause, the parties
                 hereto acknowledge and agree that Global Partner's Employment
                 shall not be deemed terminated pursuant to Section 4(a), 4(b)
                 or 4(c).

                 (iii)    Global Partner agrees that pending the conclusion of
         any arbitration initiated pursuant to Section 4(h)(i) or 4(h)(ii) and
         the entry of a final judgment by a court of competent jurisdiction as
         contemplated by Section 9(b), Global Partner will continue to carry
         out the duties of his Employment as set forth herein.  In addition,
         Global Partner, the Company and INVESCO each agree to use all
         reasonable efforts such that the pending disagreement between Global
         Partner and the Company and INVESCO will not adversely impact the
         business or operations of the Company or INVESCO or their respective
         employment, client or other business relationships, including, without
         limitation, reasonable efforts to keep the fact of such disagreement
         and the subject matter thereof as confidential as possible in the
         circumstances.

         5.      Confidentiality.  Global Partner agrees that both during the
term of this Agreement and after the termination of this Agreement, Global
Partner will hold in a fiduciary capacity for the benefit of the Company, and
will not directly or indirectly use or disclose (except as authorized in
writing by the Company) any "Confidential Information," as defined hereafter.
The term "Confidential Information" as used in this Agreement shall mean and
include any information, data and know-how relating to the business of the
Company or any member of the AMVESCO Group that is disclosed to Global Partner
by the Company (or a member of the AMVESCO Group) or known by him as a result
of his relationship with the Company or any member of the AMVESCO Group and not
generally within the public domain including, but not limited to, all
intellectual property and proprietary research developed by and/or known to
Global Partner during his Employment with the AMVESCO Group (including the
Company).  The term "Confidential Information" does not include information
that has become generally available to the public by act of one who has the
right to disclose such information through presentation or otherwise without





                                       6
<PAGE>   7
violating any right of the Company, any member of the AMVESCO Group or the
client to which such information pertains.

         6.      Right to Material; Return of Material.  Global Partner agrees
that all records, files, memoranda, data in machine readable form, reports, fee
lists, customer lists, drawings, plans, sketches, documents and the like,
relating to the business of the Company or any member of the AMVESCO Group,
including, but not limited to, all intellectual property and proprietary
research which Global Partner shall use or develop or come in contact with in
the course of or as the result of his employment with the Company or any member
of the AMVESCO Group shall remain the sole property of the Company and/or the
AMVESCO Group (as the case may be).

         Upon termination of Global Partner's employment with the Company or
INVESCO for any reason, Global Partner will deliver promptly to the Company all
materials, documents, plans, records, notes, drawings, designs or papers, in
whatever recorded form, and any copies thereof in Global Partner's possession
or control relating in any way to the business of the Company and/or the
AMVESCO Group, which at all times shall be the property of the Company.  Global
Partner shall certify to the Company that any such data in machine readable
form has been removed from any computer personally owned by Global Partner and
all back up copies made by Global Partner have been destroyed.

         7.      Work for Hire Acknowledgment; Assignment.  Global Partner
acknowledges that all of Global Partner's work on and contributions to the
business of the Company and/or the AMVESCO Group, including, without
limitation, any and all investment decisions, models, processes and methodology
or any other contribution to such business (such as quantitative models,
designs, artwork and other expressions in any recorded form) (collectively, the
"Works") are within the scope of Global Partner's employment and are a part of
the services, duties and responsibilities of Global Partner.  All of Global
Partner's work on and contributions to the Works will be rendered and made by
Global Partner for, at the instigation of, and under the overall direction of
the Company, and all of Global Partner's said work and contributions, as well
as the Works, are and at all times shall be regarded as "work made for hire" as
that term is used in the United States Copyright Laws.  Global Partner also
acknowledges that investment decisions are a result of the Company's effort and
the performance or other "track" record of any mutual fund or other account is
a result of the Company effort and is the property of the Company and not of
Global Partner.  Without curtailing or limiting these acknowledgments, Global
Partner hereby assigns, grants and delivers exclusively to the Company all
rights, titles and interests in and to any such Works, and all copies and
versions, including all copyrights and renewals.  At any time upon request by
the Company, Global Partner will execute and deliver to the Company, or its
successors and assigns, such other and further assignments, instruments and
documents as the Company (or such successors or assigns) from time to time
reasonably may request for the purpose of establishing, registering,
evidencing, and enforcing or defending





                                       7
<PAGE>   8
its complete, exclusive, perpetual and worldwide ownership of all rights,
titles, interests and copyrights, in and to the Works, and Global Partner
hereby constitutes and appoints the Company as his agent and attorney-in-fact,
with full power of substitution, to execute and deliver such assignments,
instruments or documents as Global Partner may fail or refuse to execute and
deliver, this power and agency being coupled with an interest and being
irrevocable.

         8.      No Solicitation and Non-Competition.  Global Partner will not,
(i) in the case of a termination of Global Partner's Employment for any reason
effective as of a date prior to the Fourth Anniversary, at any time prior to
the later of (x) the Fourth Anniversary or (y) the second anniversary of the
termination of Global Partner's Employment pursuant to this Agreement or (ii)
in the case of a termination of Global Partner's Employment for any reason
effective as of a date after the Fourth Anniversary, at any time prior to the
first anniversary of the date a notice of termination of Global Partner's
Employment is delivered pursuant to Section 4 of this Agreement, in any such
case, without the express prior written consent of the Board of Directors of
the Company and INVESCO, directly or indirectly, either engage in or
participate in or invest in or assist, as owner, part-owner, shareholder (in
the case of any publicly traded company, ownership of any equity interest
exceeding 2.5 %), partner, principal, director, officer, trustee, employee,
agent or consultant, or in any other capacity, any planned or existing firm,
corporation, or other business organization (other than the Company and INVESCO
(or any subsidiary of the Company or INVESCO) and any foundation established by
any AIM Senior Officer (as defined in Exhibit B, Part I hereto)) which engages
in any of the following (except that Global Partner shall be permitted, on his
own behalf or on behalf of any new business organization established by Global
Partner, either alone or together with those other AIM Senior Officers who are
then no longer employed by the Company or any member of the AMVESCO Group, to
manage the investment of his own personal assets and the assets of such other
AIM Senior Officers, together with up to an aggregate of $100 million in assets
of any other person or entity):

                 (a)      the business of furnishing investment advice to
         Investment Companies (as    that term is defined in the Investment
         Company Act of 1940, as amended) in the United    States;

                 (b)      the business of furnishing investment advisory or
         management services to clients other than Investment Companies in the
         United States;

                 (c)      assisting any Investment Company with which the ISG
         has or ever (whether before or after the date hereof) had any
         investment advisory or management agreement (each a "Fund") or any
         other present or past client of the ISG (a "Client") in internalizing
         the investment management or investment advisory function or any other
         function or service provided by the ISG to any such Fund or Client,
         subject to





                                       8
<PAGE>   9
         Global Partner's fiduciary duty owed to any of the Funds or the
directors or trustees thereof;,

                 (d)      being a party to any contractual or business
         relationship with any Fund or Client involving services related to
         investment management or investment advisory services, if such related
         services are also provided by the ISG or by any other person at the
         ISG's direction to any Fund or Client;

                 (e)      soliciting, offering to employ or employing, directly
         or indirectly, in any capacity any person who is or was (at any time
         after the date hereof) was a director, officer, trustee, partner,
         employee or client of the ISG, any member of the AMVESCO Group or of
         any of the Funds or inducing any such person to sever his or her
         relationship therewith or to establish a relationship with any other
         person;

                 (f)      soliciting or otherwise attempting to establish,
         directly or indirectly, for himself or any other person, firm or
         entity any business relationship involving or relating to the
         provision of investment management or advisory services with any firm,
         corporation or other business organization who is or ever (whether
         before or after the date hereof) was a customer or client of the
         Company or any member of the AMVESCO Group; or

                 (g)      authorizing or knowingly approving the taking of any
         action set forth in clauses (c) through (f) above by any other person.

         9.      Remedies. (a) The parties acknowledge that a breach or threat
to breach any of the terms of this Agreement by Global Partner would result in
material and irreparable damage and injury to the Company and INVESCO, and that
it would be difficult or impossible to establish the full monetary value of
such damage.  Therefore, in addition to any other rights or remedies that the
Company or any member of the AMVESCO Group may have at law or in equity, the
Company and the AMVESCO Group shall be entitled to injunctive relief by a court
of appropriate jurisdiction in the event of Global Partner's breach or
threatened breach of any of the terms contained in this Agreement.  In the
event of any breach or threatened breach of this Agreement by Global Partner,
if the Company or any member of the AMVESCO Group should employ attorneys or
incur other expenses for the enforcement of any obligation or agreement of
Global Partner contained herein and shall prevail, Global Partner shall
reimburse the Company or such member, as the case may be, for its reasonable
attorneys' fees and such other expenses so incurred.  If Global Partner employs
attorneys or incurs other expenses in connection with the defense of any action
for injunctive relief hereunder and Global Partner prevails, the Company shall
reimburse Global Partner for his reasonable attorneys' fees and such other
expenses so incurred.





                                       9
<PAGE>   10
         (b)     The Company and Global Partner agree to submit to final and 
binding arbitration any and all disputes, claims (whether in tort, contract,
statutory or otherwise) and/or disagreements concerning the interpretation or
application of this Agreement, the Global Partner's Employment by the Company
and INVESCO and/or the termination of this Agreement and/or the Global
Partner's Employment by the Company and INVESCO.  Any such dispute, claim
and/or disagreement shall be resolved by arbitration, by a mutually acceptable
arbitrator, in accordance with the Commercial Arbitration Rules of the American
Arbitration Association (the "AAA").  If, within 30 days of the initiation of
an arbitration hereunder, the parties cannot agree on a mutually acceptable
arbitrator, each party will designate an arbitrator pursuant to Rule 14 of the
AAA Rules.  The appointed arbitrators shall appoint a neutral arbitrator from
the panel in the manner prescribed in Rule 13 of the AAA Rules.  The
Arbitrators shall apply the law of Texas.  All meetings of the Arbitrators
shall be held in Houston, Texas.  Global Partner and the Company agree that the
decision of the arbitrators selected hereunder shall be final and binding on
both parties.  This arbitration provision is expressly made pursuant to and
shall be governed by the Federal Arbitration Act, 9 U.S.C. Sections 1-14.  The
Parties hereto agree that, pursuant to Section 9 of the Federal Arbitration
Act, a judgment of the United States District Court for the Southern District
of Texas, Houston Division, shall be entered upon the award made pursuant to
the arbitration provision.  The provisions of this Section 9(b) do not apply to
actions brought by the Company or any member of the AMVESCO Group for
injunctive or other equitable relief under Section 9(a) in respect of claims
under Sections 4, 5, 6, 7, 8 or 9(b).

         10.     Assignments.  The terms and provisions of this Agreement shall
inure to the benefit of and be binding upon the Company, INVESCO and any of
their respective successors and assigns and shall inure to the benefit of and
be binding upon Global Partner and his heirs and personal representatives.  The
parties hereto specifically acknowledge and agree that, in connection with the
assignment of the assets of the Company to Newco Sub (as defined in the Merger
Agreement) immediately following the consummation of the Merger, this Agreement
will be assigned to Newco Sub.

         11. Applicable Law.  This Agreement has been entered into in and shall
be governed by and construed under the internal laws of the state of Texas.

         12.     Notice.  Any notice required or permitted to be given pursuant
to this Agreement shall be deemed sufficiently given when delivered in person
or when deposited in the United States mail or by Federal Express or similar
overnight delivery service or by telecopy or fax.

         13.     Term.  The parties hereto agree that Global Partner's
Employment shall commence on the effective date of the Merger and shall
continue until it is terminated (a) by the Company or INVESCO pursuant to
Section 4 (a)(i) or 4(b); (b) due to death or disability pursuant to Section
4(d); (c) subject to Section 4(h), by Global Partner on 60 days prior





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<PAGE>   11
written notice to the Company and INVESCO pursuant to Section 4(c); or (d)
effective as of a date on or after the Fourth Anniversary, by the Company,
INVESCO or Global Partner pursuant to Section 4(a) (ii) .

         14.     Non-waiver.  The failure of the Company, INVESCO or Global
Partner to insist upon strict performance of the terms of this Agreement or to
exercise any option herein, shall not be construed as a waiver or a
relinquishment in the future of such term or option, but that the same shall
continue in full force and effect.

         15.     Interpretation; Severability of Invalid Provisions.  All
rights and restrictions contained in this Agreement may be exercised and shall
be applicable and binding only to the extent that they do not violate any
applicable laws and are intended to be limited to the extent necessary so that
they will not render this Agreement illegal, invalid or unenforceable.  If any
term of this Agreement shall be held to be illegal, invalid or unenforceable by
a court of competent jurisdiction, the remaining terms shall remain in full
force and effect.  The provisions of this Agreement do not in any way limit or
abridge the Company's or INVESCO's rights under the laws of unfair competition,
trade secret, copyright, patent, trademark or any other applicable law(s), all
of which are in addition to and cumulative of the Company's and INVESCO's
rights under this Agreement.  The existence of any claim by Global Partner
against the Company or INVESCO, whether predicated on this Agreement or
otherwise, shall not constitute a defense to enforcement by the Company or
INVESCO of any or all of such provision or covenants.

         16.     Entire Agreement.  This Agreement constitutes the entire
agreement between the Company, INVESCO and Global Partner with respect to the
subject matter, and supersedes any prior agreement or understanding with
respect to the subject matter hereof, including, without limitation, any
existing employment agreement between Global Partner and the Company or any
affiliate thereof.





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<PAGE>   12
         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed under seal as of the day and year first above written.


                                         A I M Management Group Inc.
                                         
                                         
                                         
                                         By: /s/ CHARLES T. BAUER              
                                            ------------------------------------
                                                                                
                                         Title: Chairman and CEO                
                                               ---------------------------------
                                                                                
                                                                                
                                         INVESCO PLC                            
                                                                                
                                         By: ILLEGIBLE                         
                                            ------------------------------------
                                                                                
                                         Title: COMPANY SECRETARY              
                                               ---------------------------------
                                                                                
                                                                                
                                         Global Partner                         
                                                                                
                                                                                
                                         By: /s/ ROBERT H. GRAHAM              
                                            ------------------------------------
                                             Robert H. Graham
<PAGE>   13
                                   EXHIBIT A
                               To Agreement among


                                Robert H. Graham


                          A I M Management Group Inc.


                                      and


                                  INVESCO PLC

     I.    Regular Compensation and Benefits.  As basic compensation for the
services of Global Partner, the Company shall pay Global Partner an initial
base salary of $450,000 per annum, subject to withholdings pursuant to
applicable law or regulation, and payable in accordance with the payment
practices adopted by the Company.  The base salary shall be reviewed by the
Company annually, and the rate thereof may be adjusted upward upon such review.
During the term of Employment, Global Partner shall be entitled to receive the
following benefits:

                 (i)   Group hospitalization, major medical, long-term
                       disability and life insurance coverage to the extent
                       such coverage is available to other personnel of the
                       Company in comparable positions with and having duties
                       comparable to those of the Global Partner and such other
                       insurance coverage as is similarly available;

                 (ii)  Participation in any bonus or profit sharing plan or
                       pension that the Company makes generally available to
                       its key employees; and

                 (iii) Such vacation, holidays, and other paid or unpaid leaves
                       of absence as the Company's Board of Directors may
                       approve.

     The Company and INVESCO agree to reimburse Global Partner for all
reasonable expenses incurred by him on behalf of the Company of INVESCO, as the
case may be, and Global Partner acknowledges that work beyond the standard
working hours may be necessary consistent with past practices.  The combined
amount of base salary and cash bonus attributable to any one year shall be at
least the total amount set forth in II of this Exhibit A.
<PAGE>   14
     II.   Minimum Compensation.  Global Partner's Minimum Compensation
(calendar year basis) shall be:

                       Salary       $450,000

                 The above amount will be pro-rated for any partial year on a
daily basis.





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<PAGE>   15
                               EXHIBIT B - PART I

                                  GOOD REASON


Subject to compliance with the procedures and covenants contained in Section
4(h)(i) and 4(h)(iii) of the Agreement, Good Reason shall mean the occurrence
of any of the following events that (i) is not otherwise agreed to in writing
by at least a majority of the AIM Designees, as defined in the Voting
Agreement, dated as of November 4, 1996, by and among INVESCO, the Shareholders
(as defined in such Voting Agreement), the members of the INVESCO Board of
Directors as of the date of such Voting Agreement listed on the signature page
thereto and the Original Designees, as defined in such Voting Agreement, listed
on the signature page thereto (the "Voting Agreement") and (ii) except as
specified otherwise below, is not cured by the Company or INVESCO within 60
days following its receipt of written notice from Global Partner thereof:

     1.    Without Global Partner's express written consent, the assignment to
           him by INVESCO or by the Company at the direction of INVESCO of any
           material duties that are inconsistent with his positions, duties,
           responsibilities and status as set forth in Section 1 of the
           Agreement, or a material diminishment by INVESCO or by the Company
           at the direction of INVESCO of his responsibilities, which change or
           inconsistency is not cured by the Company or INVESCO within 30 days
           following its receipt of written notice from Global Partner
           specifying such change or inconsistency.

     2.    Without Global Partner's express written consent, any requirement of
           INVESCO or of the Company at the direction of INVESCO that Global
           Partner be based outside the Houston metropolitan area or perform a
           substantial portion of his services hereunder at any location or
           locations other than the Houston metropolitan area (except for
           ordinary business related travel outside of such area), which
           requirement is not rescinded by the Company or INVESCO within 30
           days following its receipt of notice from Global Partner specifying
           the requirement.

     3.    The Company's or INVESCO's wilful and material breach of any of the
           provisions of this Agreement, which breach is not cured by the
           Company or INVESCO within 30 days following its receipt of written
           notice from Global Partner specifying the breach.

     4.    Any change by INVESCO of the corporate name of the Company or any of
           the Company's existing subsidiaries.
<PAGE>   16
     5.    Any wilful breach by INVESCO of the portion of Section 3.2.9 of the
           Merger Agreement relating to the change of the name of INVESCO PLC
           to AMVESCO PLC.

     6.    If for any reason other than his death, disability or resignation or
           other separation from employment, prior to the Fourth Anniversary,
           Charles T. Bauer is not nominated to be Vice Chairman of the Board
           of INVESCO.

     7.    If, prior to the Fourth Anniversary, INVESCO causes more than one
           person to serve simultaneously as Vice Chairman of the Board of
           INVESCO.

     8.    If, as a result of any act or failure to act of INVESCO, the ISG
           management committee fails to constitute one of the two management
           committees of INVESCO or there are more than two management
           committees of INVESCO.

     9.    If INVESCO causes the chief executive of any business within the ISG
           to report directly to any person other than one or more of Robert H.
           Graham, Charles T. Bauer, Gary Crum and Michael Cemo (or such of
           them who are employed by the Company or INVESCO at the relevant time
           (the "AIM Senior Officers")) or a designee thereof or causes any
           principal executive officer of any such business to report directly
           to any person other than the chief executive of such business.

     10.   If at any time INVESCO precludes the AIM Senior Officers from
           appointing two members of the other management committee of INVESCO.

     11.   If INVESCO precludes the AIM Senior Officers from determining the
           composition and number of members of the ISG Management Committee
           (other than in respect of 2 non-ISG officers of INVESCO who may be
           appointed by the INVESCO Designees (as defined in the Voting
           Agreement)).

     12.   If INVESCO precludes the management committee of the ISG from (i)
           managing the daily operations of the businesses of the ISG,
           including without limitation, trading risk, credit risk, information
           technology, internal audit, client business decisions and
           infrastructure decisions, or (ii) except to the extent duplicative of
           professional or other service providers retained by INVESCO to
           represent or advise the AMVESCO Group, selecting professional
           advisors and other similar service providers for the constituent
           businesses, it being understood that the responsibility of the
           management committee of the ISG for daily operations of the ISG
           shall be exercised in a manner consistent with the business and
           strategic plans set by the INVESCO Board of Directors





                                       2
<PAGE>   17
           and the policies and procedures of INVESCO approved by the Board
           applicable generally to all members of the AMVESCO Group.

     13.   If INVESCO causes the employment of any other AIM Senior Officer to
           be involuntarily terminated without Cause.

     14.   If, following the written request of Global Partner, INVESCO refuses
           to nominate him to the Board of Directors or comparable governing
           body, if any, of any of the constituent businesses of the ISG.

     15.   If, at any time prior to the Fourth Anniversary, the General Counsel
           of INVESCO is someone not approved in writing by a majority of the
           AIM Senior Officers or if the Office of General Counsel of INVESCO
           is vacant for more than 90 consecutive days as a result of the
           wilful failure of INVESCO to diligently conduct an executive search
           for a qualified individual to fill such vacancy, in all such cases,
           provided that from time to time the Chief Executive Officer of
           INVESCO shall be consulted concerning the candidates being
           considered to fill any such vacancy and any candidate selected to
           fill such vacancy shall be reasonably acceptable to the Chief
           Executive Officer of INVESCO and the INVESCO Board.





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<PAGE>   18
                              APPENDIX B - PART II

                           INDIVIDUAL SERVICES GROUP


     The primary geographic area of ISG's operations will be North America,
provided ISG will not be precluded from organizing offshore funds, from
distributing its products offshore or from entering into joint ventures
offshore e.g.  Pakistan, it being understood that any such activities shall be
undertaken only in a manner consistent with the business plan of INVESCO as
approved by the Board of Directors of INVESCO.

     To the extent any existing North American entity within the AMVESCO Group
operates in businesses covered by the ISG as well as other members of the
AMVESCO Group, such entities shall establish appropriate dual reporting or
similar mechanisms to facilitate reporting to the appropriate division.

     The businesses reporting to the ISG are the businesses operated by the
Company as of the date hereof and all businesses operated by INVESCO or its
subsidiaries which are part of the INVESCO Individual Services Group as of the
date hereof (collectively, the "ISG Companies') and any other company hereafter
formed or acquired which engages in the business of the type engaged in by the
ISG Companies as of the date hereof.