<PAGE>   1
                                                                  EXHIBIT 10.19

                      WAIVER, CONSENT AND AMENDMENT NO. 1

                                                  Dated as of February 13, 1997

    WAIVER, CONSENT AND AMENDMENT NO. 1 (this "Amendment") among A I M
Management Group Inc., a Delaware corporation (the "Borrower"), the banks,
financial institutions and other institutional lenders parties to the Credit
Agreement referred to below (collectively, the "Lenders"), Citibank, N.A., as
administrative agent and lead managing agent (the "Lead Managing Agent") for
the Lenders, and the co-agents listed on the signature pages of the Credit
Agreement referred to below, as co-agents (the "Co-Agents" and, together with
the Lead Managing Agent, the "Agents").

                      PRELIMINARY STATEMENTS:

    (1)  The Borrower, the Lenders and the Agents have entered into a Credit
Agreement dated as of June 26, 1996 (the "Credit Agreement").  Capitalized
terms not otherwise defined in this Amendment have the same meanings as
specified in the Credit Agreement.

    (2)  The Borrower has entered into an Agreement and Plan of Merger dated as
of November 4, 1996 (as amended, supplemented or otherwise modified from time
to time, the "Merger Agreement") with INVESCO PLC, a company organized under
the laws of England ("INVESCO"), and INVESCO Group Services, Inc., pursuant to
which the Borrower will be merged (the "Merger") with a newly-organized
subsidiary ("Newco") of INVESCO.  Newco will be the surviving corporation of
the Merger.  Immediately following the Merger, the assets and liabilities of
the Borrower (including, without limitation, the rights and obligations of the
Borrower under the Credit Agreement) will be contributed (the "Transfer") to a
direct, newly-organized subsidiary of Newco to be known as AIM Management Group
Acquisition Corp. (which after consummation of the Transfer will change its
name to A I M Management Group Inc.)("New AIM").  The rights and obligations of
the Borrower under the Credit Agreement will be transferred pursuant to a
contribution and assumption agreement (the "Contribution Agreement").  The
Merger and the Transfer are collectively referred to as the "Transaction".  The
Borrower hereby requests that the Required Lenders consent to the consummation
of the Transaction and grant the waivers and amendments under the Loan
Documents needed to facilitate the Transaction and as otherwise set forth
below.

    (3)  The Required Lenders are, on the terms and conditions stated below,
willing to grant the requests of the Borrower and the Borrower and the Required
Lenders have agreed to amend the Credit Agreement as hereinafter set forth.




<PAGE>   2


                                       2

         NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements contained herein, the parties hereto agree as follows:

         SECTION 1. Waiver and Consent.  Subject to the satisfaction of the
conditions precedent set forth in Section 4(a), the Required Lenders hereby
consent to the consummation of the Transaction and in furtherance thereof,
agree to the following:

         (a)  Section 3.02(a) of the Credit Agreement, which provides for a
    mandatory prepayment as a result of certain Asset Sales and a subsequent
    permanent reduction of the Total Tranche A Commitment pursuant to Section
    2.04(b)(i) in an amount equal to any such prepayment, is waived to the
    extent the Transfer, as contemplated by the Transaction, constitutes an
    Asset Sale.

         (b)  Section 7.04 of the Credit Agreement, pursuant to which the
    Borrower covenanted not to merge with any Person, is waived to the extent
    required to permit the Merger and to otherwise consummate the Transaction.

         (c)  Section 7.05(iv) of the Credit Agreement, pursuant to which the
    Borrower covenanted not to repurchase, redeem, defease or retire or
    otherwise acquire for value, prior to any scheduled repayment, sinking fund
    payment or maturity, any Pari Passu Debt, is waived to the extent required
    to permit the Borrower to tender for and redeem any Senior Notes tendered
    pursuant to the change of control tender provisions of the Senior Notes in
    connection with the Merger, without such payments being included in
    Restricted Payments.

         (d)  Section 7.06 of the Credit Agreement, pursuant to which the
    Borrower covenanted not to sell or otherwise dispose of all or
    substantially all of its assets, is waived to the extent required to permit
    the Transfer and to otherwise consummate the Transaction.

         (e)  Section 8.01(o) of the Credit Agreement, pursuant to which an
    Event of Default occurs if (i) during a period of two consecutive years,
    individuals who at the beginning of such period constituted the Board of
    Directors of the Borrower (together with any new directors whose election
    to such Board or whose nomination for election by the shareholders of the
    Borrower was approved by a vote of at least 66-2/3% of the directors then
    still in office who were either directors at the beginning of such period
    or whose election or nomination for election was previously so approved)
    cease for any reason to constitute a majority of such Board of Directors
    then in office, or (ii) any "person" or "group" other than any member of a
    Key Shareholder Group shall at any time Beneficially Own a percentage of
    the outstanding shares of Voting Stock of the Borrower equal to or greater
    than 50% of the aggregate percentage of the outstanding shares of the
    Voting Stock of the Borrower Beneficially
<PAGE>   3



                                       3

    Owned by all Key Shareholder Groups, is waived to the extent required to
    permit the Merger and to otherwise consummate the Transaction.

         (f)  Section 8.01(p) of the Credit Agreement, pursuant to which an
    Event of Default occurs if at any time the Key Shareholder Groups or any
    one or more of the members thereof shall cease to Beneficially Own in the
    aggregate at least 20% of the outstanding Voting Stock of the Borrower, is
    waived to the extent required to permit the Merger and to otherwise
    consummate the Transaction.

         (g)  Section 8.01(q) of the Credit Agreement, pursuant to which an
    Event of Default occurs if any change in Beneficial Ownership of the
    outstanding shares of Voting Stock of the Borrower shall occur
    necessitating any consent of the shareholders or directors of any
    Investment Company and such consent is not obtained in a timely manner, or
    with respect to the Management Contracts, the consents relating to 90%
    thereof are not obtained with the statutory period necessary to prevent the
    termination thereof, is waived to the extent required to permit the Merger
    and to otherwise consummate the Transaction.


    SECTION 2. Amendments to Credit Agreement.  The Credit Agreement is,
effective as of the date hereof and subject to the satisfaction of the
conditions precedent set forth in Section 4(a), hereby amended as follows:

         (a)  Section 1.01 and the definition of "Net Income" is amended by
    deleting the paragraph in its entirety and adding the following:

             "Net Income" means, with respect to any period, the net income of
             the Borrower and its Subsidiaries for such period, all determined
             in accordance with GAAP on a Consolidated basis, provided, that
             there shall be excluded (a) all extraordinary gains or losses
             (less all fees and expenses relating thereto), (b) any gain or
             loss, net of taxes, realized upon the termination of any employee
             pension benefit plan, (c) the income of any Person accrued prior
             to the date it becomes a Subsidiary or is merged into or
             consolidated with the Borrower and its Subsidiaries, (d) the
             income of any Person (other than a Subsidiary) in which the
             Borrower and its Subsidiaries has an ownership interest, except to
             the extent that any such income has been actually received by the
             Borrower and its Subsidiaries in the form of dividends or similar
             distributions, (e) gains or losses (less all fees and expenses
             relating thereto) in respect of dispositions of assets other than
             in the ordinary course of business and (f) the net income of any
             Subsidiary to the extent that the declaration of dividends or
             similar distributions by that Subsidiary of that income is not at
             the time permitted, directly or indirectly, by operation of the
             terms of its charter
<PAGE>   4
                                       4

             or any agreement, instrument, judgment, decree, order, statute,
             rule or governmental regulations applicable to that Subsidiary or
             its shareholders.

         (b) Section 1.01 and the definition of "Permitted Investments" is
    amended by deleting the phrase that begins with", provided" in subsection
    (i) and ends with "at any time".

         (c) Section 7.05(a)(2)(A) is amended by deleting subsection (A), by
    changing December 31, 1995 to November 3, 1993 in subsection (B) and by
    changing each reference in subsections (C), (D), (E) and (F) from "the
    Third Restatement Date" to "November 3, 1993".

         (e) Section 7.20 is amended by deleting "(i)" in the first line, by
    substituting "Section 7.20. " for " clause 7.20(i);  "and by deleting 
    clause (ii) in its entirety.

         (f) Section 8.01(f) is amended by substituting "$5,000,000" for
    $1,000,000".


         (g) Section 8.01(h) is amended by substituting "$5,000,000" for
    $1,000,000".



         SECTION 3. Further Amendments Upon Consummation of Transaction.  When,
and only when, on or before March 3, 1997 the Transaction is consummated, and
subject to the satisfaction of the conditions precedent set forth in Section
4(b), the Credit Agreement is hereby further amended as follows:


         (a) The recital of the parties is amended by substituting "A I M
    Management Acquisition Corp." for "A I M Management Group Inc.".

         (b) Section 7.03 is amended by deleting "and" at the end of
    subsection (j), deleting the period at the end of subsection (k) and
    substituting therefor "; and" and by adding to the end of Section 7.03 a
    new subsection (l), to read as follows:

                 (1)  the Borrower and AIM Advisors may become and remain liable
             with respect to guaranties of the indebtedness of INVESCO PLC
             under that certain Credit Agreement dated as of February 13, 1997
             (the "INVESCO Credit Agreement") among INVESCO PLC, as borrower,
             Citibank and NationsBank, N.A. ("NationsBank") as agents, the
             lenders and co-agents parties thereto and NationsBank, as funding
             agent; provided, however, that
<PAGE>   5
                                       5

             any such guaranties by AIM Advisors shall contain no terms more
             favorable to the beneficiaries thereof than those set forth in the
             AIM Guaranties.

         (c)  Section 8.01(o) is amended by deleting the paragraph and by
    adding a new subsection (o) to read as follows:

         (o)  (i) Any Person or two or more Persons acting in concert shall
              have acquired beneficial ownership (within the meaning of Rule
              13d-3 of the Securities and Exchange Commission under the
              Securities Exchange Act of 1934), directly or indirectly, of
              Voting Stock of INVESCO PLC or the Borrower, as the case may
              be, (or other securities convertible into such Voting Stock)
              representing 20% or more of the combined voting power of all
              Voting Stock of INVESCO PLC or the Borrower, as the case may
              be; or (ii) during any period of up to 24 consecutive months,
              commencing after the date of this Agreement, individuals who
              at the beginning of such 24-month period were directors of
              INVESCO PLC or the Borrower, as the case may be, shall cease
              for any reason to constitute a majority of the board of
              directors of INVESCO PLC or the Borrower, as the case may be
              (except, in the cases of clauses (i) and (ii), in connection
              with the Merger or pursuant to the Merger Agreement and the
              Voting Agreement dated as of November 4, 1996 among INVESCO
              PLC and the other parties named therein);
              
              (d) Section 8.01(p) is amended by deleting the paragraph in
    its entirety.

              (e) Section 8.01(q) is amended by deleting the paragraph in
    its entirety.

              (f) Section 8.01(r) is amended by substituting "(p)" for
    "(r)", deleting the paragraph in its entirety and adding the following:

                  Any ERISA Event shall have occurred with respect to a
              Plan, or any Loan Party or any ERISA Affiliate shall have
              incurred or be reasonably expected to incur liability under
              Section 4064 or 4069 of ERISA and the sum (determined as of
              the date of occurrence of such ERISA Event) of the
              Insufficiency of such Plan and the Insufficiency of any and
              all other Plans with respect to which an ERISA Event shall
              have occurred and then exist (or the liability of the Loan
              Parties and the ERISA Affiliates incurred or expected to be
              incurred with respect to Section 4064 or 4069 of ERISA or
              related to such ERISA Event) exceeds $10,000,000; or
              
              (g) Section 8.01(s) is amended by substituting "(q)" for "(s)".
<PAGE>   6

                                       6

                 (h) Section 8.01 (t) is amended by substituting " (r) " for "
         (t) ", deleting the paragraph in its entirety and adding the following:

                     Any Loan Party or any ERISA Affiliate shall have been
                 notified by the sponsor of a Multiemployer Plan that it has
                 incurred Withdrawal Liability to such Multiemployer Plan in an
                 amount that, when aggregated with all other amounts required
                 to be paid to Multiemployer Plans by the Loan Parties and the
                 ERISA Affiliates as Withdrawal Liability (determined as of the
                 date of such notification), exceeds $10,000,000 or requires
                 payments exceeding $2,500,000 per annum; or


                 (i) Section 8.01(u) is amended by substituting "(s)" for
         "(u)", deleting the paragraph in its entirety and adding the following:

                     Any Loan Party or any ERISA Affiliate shall have been
                 notified by the sponsor of a Multiemployer Plan that such
                 Multiemployer Plan is in reorganization or is being
                 terminated, within the meaning of Title IV of ERISA, and as a
                 result of such reorganization or termination the aggregate
                 annual contributions of the Loan Parties and the ERISA
                 Affiliates to all Multiemployer Plans that are then in
                 reorganization or being terminated have been or will be
                 increased over the amounts contributed to such Multiemployer
                 Plans for the plan years of such Multiemployer Plans
                 immediately preceding the plan year in which such
                 reorganization or termination occurs by an amount exceeding
                 $10,000,000;


                 (j) Section 1.02 is amended by deleting the definitions of
         "ERISA Affiliate", "ERISA Event", "Multiemployer Plan", Multiple 
         Employer Plan", "Single Employer Plan" and "Welfare Plan" and adding 
         the following definitions:

                     "ERISA Affiliate" means any Person that for purposes of
                 Title IV of ERISA is a member of any Loan Party's controlled
                 group, or under common control with any Loan Party, within the
                 meaning of Section 414 (b) or (c) of the Internal Revenue Code
                 or, for purposes of Sections 412(c)(ii) and 412(u) of the
                 Internal Revenue Code, under Section 414(m) or (o) of the
                 Internal Revenue Code.

                     "ERISA Event" means (a) (i) the occurrence of a reportable
                 event, within the meaning of Section 4043 of ERISA, with
                 respect to any Plan unless the 30-day notice requirement with
                 respect to such event has been waived by the PBGC, or (ii) at
                 the time when the requirements of subsection (1) of
<PAGE>   7
                                       7

                 Section 4043(b) of ERISA (without regard to subsection (2) of
                 such Section) are applicable to any Loan Party or any ERISA
                 Affiliate, an event described in paragraph (9), (10), (11),
                 (12) or (13) of Section 4043(c) of ERISA is reasonably
                 expected to occur with respect to a Plan within the following
                 30 days; (b) the filing by any Loan Party or any ERISA
                 Affiliate of an application for a minimum funding waiver with
                 respect to a Plan; (c) the provision by the administrator of
                 any Plan of a notice of intent to terminate a Plan pursuant to
                 Section 4041(a)(2) of ERISA (including any such notice with
                 respect to a plan amendment referred to in Section 4041(e) of
                 ERISA); (d) the cessation of operations at a facility of any
                 Loan Party or any ERISA Affiliate in the circumstances
                 described in Section 4062(e) of ERISA; (e) the withdrawal by
                 any Loan Party or any ERISA Affiliate from a Multiple Employer
                 Plan during a plan year for which it was a substantial
                 employer, as defined in Section 4001(a)(2) of ERISA; (f) the
                 conditions for the imposition of a lien under Section 302(f)
                 of ERISA on the assets of any Loan Party or any ERISA
                 Affiliate shall have been met with respect to any Plan; (g)
                 the adoption of an amendment to a Plan requiring any Loan
                 Party or any ERISA Affiliate to provide security to such Plan
                 pursuant to Section 307 of ERISA; or (h) the institution by
                 the PBGC of proceedings to terminate a Plan pursuant to
                 Section 4042 of ERISA, or the occurrence of any event or
                 condition described, in Section 4042 of ERISA that constitutes
                 grounds for the termination of, or the appointment of a
                 trustee to administer, a Plan; provided, however, that the
                 event or condition set forth in Section 4042(a)(4) of ERISA
                 shall be an ERISA Event only if the PBGC has notified any Loan
                 Party or any ERISA Affiliate that it has made a determination
                 under such section or that it is considering termination of a
                 Plan on such grounds.

                     "Multiemployer Plan" means a multiemployer plan, as
                 defined in Section 4001(a)(3) of ERISA, to which any Loan
                 Party or any ERISA Affiliate is making or accruing an
                 obligation to make contributions, or has within any of the
                 preceding five plan years made or accrued an obligation to
                 make contributions.

                     "Multiple Employer Plan" means a single employer plan, as
                 defined in Section 4001(a)(15) of ERISA, that is maintained
                 for current or former employees of any Loan Party or any ERISA
                 Affiliate and at least one Person other than such Loan Party
                 and the ERISA Affiliates.

                     "Single Employer Plan" means a single employer plan, as
                 defined in Section 4001(a)(15) of ERISA, that is maintained
                 for employees of any Loan Party or any ERISA Affiliate and no
                 Person other than any Loan Party and the ERISA Affiliates.
<PAGE>   8
                                       8

                 (k) Section 6.13 is amended by deleting the paragraph in its
         entirety and adding the following:

                     SECTION 6.13. Compliance with ERISA. (i) No ERISA Event
                     has occurred or is reasonably expected to occur with
                     respect to any Plan that has resulted in or is reasonably
                     expected to result in a Material Adverse Effect; (ii)
                     Schedule B (Actuarial Information) to the most recent
                     annual report (Form 5500 Series) required to be filed for
                     each Plan, copies of which have been filed with the
                     Internal Revenue Service and, with respect to each Plan
                     whose funded current liability percentage (as defined in
                     Section 302(d)(8) of ERISA) is less than 100%, furnished
                     to the Lenders, is complete and accurate and fairly
                     presents the funding status of such Plan, and since the
                     date of such Schedule B there has been no material adverse
                     change in such funding status; (iii) neither any Loan
                     Party nor any ERISA Affiliate has incurred or is
                     reasonably expected to incur (A) any liability under
                     Section 4064 or 4069 of ERISA or (B) any Withdrawal
                     Liability to any Multiemployer Plan that has resulted or
                     would be reasonably likely to result in a Material Adverse
                     Effect; (iv) neither any Loan Party nor any ERISA
                     Affiliate has been notified by the sponsor of a
                     Multiemployer Plan that such Multiemployer Plan is in
                     reorganization or has been terminated, within the meaning
                     of Title IV of ERISA, and, to the best knowledge of any
                     Loan Party or any ERISA Affiliate, no such Multiemployer
                     Plan is reasonably expected to be in reorganization or to
                     be terminated, within the meaning of Title IV of ERISA.

                 (l) Section 7.18(f) is amended by deleting the paragraph in
         its entirety and adding the following:

                     (f)  ERISA. (i)(A) promptly and in any event within 10
                     days after any Loan Party or any ERISA Affiliate knows or
                     has reason to know that (1) any ERISA Event has occurred
                     which could result in a material liability of any Loan
                     Party or any ERISA Affiliate, or (2) any Loan Party or any
                     ERISA Affiliate has incurred or is reasonably expected to
                     incur liability under Section 4064 or 4069 of ERISA, a
                     statement of the chief financial officer of the Borrower
                     describing such ERISA Event and the circumstances giving
                     rise to, and the amount of such liability, and the action,
                     if any, that such Loan Party or such ERISA Affiliate has
                     taken and proposes to take with respect thereto and (B) on
                     the date any records, documents or other information must
                     be furnished to the PBGC with respect to any Plan pursuant
                     to Section 4010 of ERISA, a copy of such records,
                     documents and information; (ii) promptly and in any event
                     within two Business Days after receipt thereof by any Loan
                     Party or any ERISA Affiliate, copies of each notice from
                     the PBGC stating its intention to terminate any Plan or to
                     have a trustee appointed to administer any
<PAGE>   9
                                       9

                     Plan; (iii) promptly and in any event within 30 days after
                     the filing thereof with the Internal Revenue Service,
                     copies of each Schedule B (Actuarial Information) to the
                     annual report (Form 5500 Series) required to be filed with
                     respect to each Plan whose funded current liability
                     percentage (as defined in Section 302(d)(8) of ERISA) is
                     less than 100%; (iv) promptly and in any event within five
                     Business Days after receipt thereof by any Loan Party or
                     any ERISA Affiliate from the sponsor of a Multiemployer
                     Plan, copies of each notice concerning (A) the imposition
                     on any Loan Party or any ERISA Affiliate of Withdrawal
                     Liability by any such Multiemployer Plan, (B) the
                     reorganization or termination, within the meaning of Title
                     IV of ERISA, of any such Multiemployer Plan or (C) the
                     amount of liability incurred, or that may be incurred, by
                     any Loan Party or any ERISA Affiliate in connection with
                     any event described in clause (A) or (B);


         SECTION 4.  Conditions of Effectiveness.  The effectiveness of this
Amendment is conditioned upon the accuracy of the factual matters described
herein.  This Amendment is subject to the provisions of Section 10.01 of the
Credit Agreement.

         (a) Sections 1 and 2 of this Amendment shall become effective as of
the date first above written when, and only when, the Lead Managing Agent shall
have received counterparts of this Amendment executed by the Borrower and the
Required Lenders or, as to any of the Lenders, advice satisfactory to the Lead
Managing Agent that such lender has executed this Amendment and the Lead
Managing Agent shall have additionally received counterparts of all of the
following documents, each such document dated the date of receipt thereof by
the Lead Managing Agent (unless otherwise specified) and in sufficient copies
for each Lender, in form and substance satisfactory to the Lead Managing Agent
(unless otherwise specified):

             (1) The Consent appended hereto (the "Consent"), executed by the
       Guarantor.

             (2) A certificate signed by a duly authorized officer of the
       Borrower stating that:

                 (i)  The representations and warranties contained in Section 5
               are correct on and as of the date of such certificate as though
               made on and as of such date; and

                 (ii) No event has occurred and is continuing that
               constitutes a Default.
<PAGE>   10


                                       10

         (b) Section 3 of this Amendment shall become effective as of the date
    of the consummation of the Merger when, and only when, in addition to the
    satisfaction of the conditions set forth in subsection (a) above, the
    Transaction is consummated and the Lead Managing Agent shall have
    additionally received counterparts of all of the following documents, each
    such document dated the date of receipt thereof by the Lead Managing Agent
    (unless otherwise specified) and in sufficient copies for each Lender, in
    form and substance satisfactory to the Lead Managing Agent (unless
    otherwise specified):

             (1) Certified copies of (i) the resolutions of the Board of
         Directors of (A) the Borrower approving the Merger and the matters
         contemplated hereby and thereby and (B) New AIM approving this
         Amendment, the Contribution Agreement and the matters contemplated
         hereby and thereby and (ii) all documents evidencing other necessary
         corporate action and governmental approvals, if any, with respect to
         this Amendment, the Contribution Agreement, the Merger, and the
         matters contemplated hereby and thereby.

             (2) A certificate of the Secretary or an Assistant Secretary of
         New AIM certifying the names and true signatures of the officers of
         New AIM authorized to sign the Assignment Agreement.

             (3) The Contribution Agreement, executed by Newco and New AIM.

             (4) A favorable opinion or opinions of Ballard Spahr Andrews &
         Ingersoll, counsel for the Borrower, to the effect that this Amendment
         has been duly executed and delivered by the Borrower and that the Loan
         Documents under which New AIM is assuming the Borrower's Obligations
         as amended hereby are the legal, valid and binding obligations of New
         AIM, enforceable in accordance with their respective terms.

             (5) A certificate signed by a duly authorized officer of New AIM
         stating that:

                   (i) The representations and warranties contained in Section 4
                 of the Contribution Agreement are correct on and as of the
                 date of such certificate as though made on and as of such
                 date; and

                   (ii) No event has occurred and is continuing that constitutes
                 a Default.

    SECTION 5. Representations and Warranties.  The Borrower represents
and warrants as follows:
<PAGE>   11

                                       11

             (a) It is a corporation duly organized, validly existing and in
         good standing under the laws of the jurisdiction indicated in the
         recital of parties to this Amendment.

             (b) The execution, delivery and performance by it of this
         Amendment and the Loan Documents, as amended hereby, to which it is or
         is to be a party, and the consummation of the transactions
         contemplated hereby, are within its corporate powers, have been duly
         authorized by all necessary corporate action and do not (i) contravene
         its charter or by-laws, (ii) violate any Requirement of Law (including
         Regulation X of the Board of Governors of the Federal Reserve System),
         (iii) conflict with or result in the breach of, or constitute a
         default under, any contract, loan agreement, indenture, mortgage, deed
         of trust, lease or other instrument binding on or affecting it, any of
         its Subsidiaries or any of their properties or (iv) result in or
         require the creation or imposition of any Lien upon or with respect to
         any of the properties of it or any of its Subsidiaries.

             (c) No authorization or approval or other action by, and no notice
         to or filing with, any governmental authority or regulatory body or
         any other third party is required for the due execution, delivery or
         performance by it of this Amendment or any of the Loan Documents, as
         amended hereby, to which it is a party, except for the filing of a
         Certificate of Merger with the Delaware Secretary of State and the
         filing of any financing statement in connection with the Transaction
         with the Texas Secretary of State.

             (d) This Amendment has been duly executed and delivered by it.
         This Amendment and each of the other Loan Documents, as amended
         hereby, to which it is a party are its legal, valid and binding
         obligations, enforceable against it in accordance with their
         respective terms.

             (e) There is no action, suit, investigation, litigation or
         proceeding affecting it or any of its Subsidiaries (including, without
         limitation, any Environmental Action) pending or threatened before any
         court, governmental agency or arbitrator that (i) could have a
         Material Adverse Effect or (ii) purports to affect the legality,
         validity or enforceability of this Amendment or any of the other Loan
         Documents, as amended hereby, or the consummation of any of the
         transactions contemplated hereby.

             (f) There has been no material adverse change in the business,
         condition (financial or otherwise), operations, performance,
         properties or prospects of the Borrower and its Subsidiaries taken as
         a whole since December 31, 1995 or since September 30, 1996.
<PAGE>   12

                                       12

         SECTION 6. Reference to and Effect on the Loan Documents. (a) On and
after the effectiveness of this Amendment, each reference in the Credit
Agreement to "this Agreement", "hereunder", "hereof" or words of like import
referring to the Credit Agreement, and each reference in the Notes and each of
the other Loan Documents to "the Credit Agreement", "thereunder", "thereof" or
words of like import referring to the Credit Agreement, shall mean and be a
reference to the Credit Agreement, as amended by this Amendment.

         (b) The Credit Agreement, the Notes and each of the other Loan
Documents, as specifically amended by this Amendment, are and shall continue to
be in full force and effect and are hereby in all respects ratified and
confirmed.  Without limiting the generality of the foregoing, the Collateral
Documents and all of the Collateral described therein do and shall continue to
secure the payment of all Obligations of the Loan Parties under the Loan
Documents, in each case as amended by this Amendment.

         (c) The execution, delivery and effectiveness of this Amendment shall
not, except as expressly provided herein, operate as a waiver of any right,
power or remedy of any Lender or the Agent under any of the Loan Documents, nor
constitute a waiver of any provision of any of the Loan Documents.

         SECTION 7. Costs and Expenses.  The Borrower agrees to pay on demand
all reasonable costs and expenses of the Administrative Agent in connection
with the preparation, execution, delivery and administration, modification and
amendment of this Amendment (including, without limitation, the reasonable fees
and expenses of counsel for the Administrative Agent) in accordance with the
terms of Section 10.04 of the Credit Agreement.

         SECTION 8. Execution in Counterparts.  This Amendment may be executed
in any number of counterparts and by different parties hereto in separate
counterparts, each of which when so executed shall be deemed to be an original
and all of which taken together shall constitute but one and the same
agreement.  Delivery of an executed counterpart of a signature page to this
Amendment by telecopier shall be effective as delivery of a manually executed
counterpart of this Amendment.

         SECTION 9. Governing Law.  This Amendment shall be governed by, and
construed in accordance with, the laws of the State of New York.
<PAGE>   13
                                       13


                   IN WITNESS WHEREOF,  the parties hereto have caused this
    Amendment to be executed by their respective officers thereunto duly
    authorized. as of the date first above written.


                        BORROWER


                              A I M MANAGEMENT GROUP INC.

                              By /s/ ROBERT H. GRAHAM                
                                 --------------------------------
                              Name:  Robert H. Graham
                              Title: President


                        MANAGING AGENTS


                              CITIBANK, N.A.,
                              as Lead Managing Agent


                              By /s/ DAVID A. DODGE                      
                                 --------------------------------
                              Name:  David A. Dodge
                              Title: Managing Director
                                     ATTORNEY-IN-FACT

                              THE CHASE MANHATTAN BANK,
                                as Co-Managing Agent


                              By /s/ ROGER A. PARKER                    
                                 --------------------------------
                              Name:  Roger A. Parker
                              Title: Vice President

<PAGE>   14

                                       14

                              NATIONSBANK, N.A. (SOUTH)
                              as Co-Managing Agent


                              By /s/ BETTY E. REED                         
                                 --------------------------------
                              Name:  Betty E. Reed
                              Title: SVP

                        TRANCHE A LENDERS


                              THE BANK OF NEW YORK


                              By Illegible                                     
                                 --------------------------------
                              Name:
                              Title: VP

                              THE CHASE MANHATTAN BANK


                              By /s/ ROGER A. PARKER                   
                                 --------------------------------
                              Name:  Roger A. Parker
                              Title: Vice President

                              CITIBANK, N.A.


                              By /s/ DAVID A. DODGE                      
                                 --------------------------------
                              Name:  David A. Dodge
                              Title: Managing Director
                              ATTORNEY-IN-FACT


                              FLEET NATIONAL BANK


                              By /s/ ANSON T. HARRIS    
                                 --------------------------------
                              Name:  Anson T. Harris
                              Title: Assistant Vice President
<PAGE>   15
                                       15


                              MELLON BANK


                              By /s/ SUSAN M. WHITEWOOD            
                                 --------------------------------
                              Name:  Susan M. Whitewood
                              Title: Asst. Vice President

                              NATIONSBANK, N.A. (SOUTH)


                              By /s/ BETTY E. REED                           
                                 --------------------------------
                              Name:  Betty E. Reed
                              Title: Senior Vice President


                              STATE STREET BANK AND
                                  TRUST COMPANY


                              By /s/ EDWARD A. SIEGEL                    
                                 --------------------------------
                              Name:  Edward A. Siegel
                              Title: Assistant Vice President