<PAGE>   1
                                                                       Exhibit 4

================================================================================

                     AMENDED AND RESTATED CREDIT AGREEMENT

                                  DATED AS OF

                               NOVEMBER 11, 1996

                                     AMONG

                             THE ALLEN GROUP INC.,

                            THE BANKS PARTY HERETO,

                                      AND

                               BANK OF MONTREAL,
                                    AS AGENT



================================================================================

                                      -22-

<PAGE>   2


                               TABLE OF CONTENTS

             (THIS TABLE OF CONTENTS IS NOT PART OF THE AGREEMENT)

<TABLE>
<CAPTION>
                                                                           PAGE
<S>                                                                          <C>
SECTION 1.       THE REVOLVING CREDIT FACILITY................................1

     Section 1.1.  Borrowings under the Revolving Credit......................1
     Section 1.2.  Letters of Credit..........................................2
     Section 1.3.  Applicable Interest Rates..................................6
     Section 1.4.  Minimum Borrowing Amounts..................................8
     Section 1.5.  Manner of Borrowing........................................8
     Section 1.6.  Interest Periods...........................................9
     Section 1.7.  Maturity of Loans.........................................10
     Section 1.8.  Optional Prepayments......................................10
     Section 1.9.  Default Rate..............................................10
     Section 1.10. The Notes.................................................11
     Section 1.11. Funding Indemnity.........................................11
     Section 1.12. Optional Commitment Terminations..........................12

SECTION 2.    FEES AND EXTENSIONS............................................12

     Section 2.1.  Fees......................................................12
     Section 2.2.  Extension of Termination Date.............................13

SECTION 3.    PLACE AND APPLICATION OF PAYMENTS..............................14

     Section 3.1   Place and Application of Payments.........................14

SECTION 4.    DEFINITIONS; INTERPRETATION....................................14

     Section 4.1   Definitions...............................................14
     Section 4.2   Interpretation............................................24

SECTION 5.    REPRESENTATIONS AND WARRANTIES.................................24

     Section 5.1   Corporate Organization and Authority......................25
     Section 5.2   Subsidiaries..............................................25
     Section 5.3   Corporate Authority and Validity of Obligations...........25
     Section 5.4.  Financial Statements......................................25
     Section 5.5.  No Material Adverse Change................................26
     Section 5.6.  No Litigation.............................................26
     Section 5.7.  Taxes.....................................................26
     Section 5.8.  Approvals.................................................26
     Section 5.9.  ERISA.....................................................26
     Section 5.10. Not an Investment Company.................................27
</TABLE>

                                      -23-

<PAGE>   3

<TABLE>
<S>                                                                           <C>
     Section 5.11. Margin Stock ............................................. 27
     Section 5.12. Compliance with Environmental Laws ....................... 27
     Section 5.13. Ownership of Property; Liens ............................. 28
     Section 5.14. No Burdensome Restrictions ............................... 28
     Section 5.15. Long Term Debt ........................................... 28

SECTION 6.    CONDITIONS PRECEDENT .......................................... 28

     Section 6.1.  Initial Credit Event ..................................... 28
     Section 6.2.  All Credit Events ........................................ 29

SECTION 7.    COVENANTS ..................................................... 30

     Section 7.1.  Corporate Existence ...................................... 30
     Section 7.2.  Maintenance .............................................. 30
     Section 7.3.  Taxes .................................................... 30
     Section 7.4.  ERISA .................................................... 30
     Section 7.5.  Insurance ................................................ 31
     Section 7.6.  Financial Reports and Other Information .................. 31
     Section 7.7.  Change of Control ........................................ 32
     Section 7.8.  Conduct of Business ...................................... 32
     Section 7.9.  Liens .................................................... 33
     Section 7.10. Compliance with Laws ..................................... 35
     Section 7.11. Regulation U ............................................. 35
     Section 7.12. Notice of Litigation ..................................... 35
     Section 7.13. Mergers, Consolidations and Sales of Assets .............. 35
     Section 7.14. Use of Property and Facilities ........................... 36
     Section 7.15. Fixed Charge Coverage Ratio .............................. 36
     Section 7.16. Consolidated Tangible Net Worth .......................... 36
     Section 7.17. Adjusted Consolidated Net Worth .......................... 36
     Section 7.18. Total Funded Debt to Cash Flow Ratio ..................... 37
     Section 7.19. Restricted Investments and Contingent Obligations ........ 37
     Section 7.20. Subsidiary Debt .......................................... 37

SECTION 8.    EVENTS OF DEFAULT AND REMEDIES ................................ 37

     Section 8.1.  Events of Default ........................................ 37
     Section 8.2.  Non-Bankruptcy Defaults .................................. 39
     Section 8.3.  Bankruptcy Defaults ...................................... 40
     Section 8.4.  Collateral for Undrawn Letters of Credit ................. 40
     Section 8.5.  Bond Letters of Credit ................................... 41
     Section 8.6.  Notice of Default ........................................ 41
     Section 8.7.  Expenses ................................................. 41

SECTION 9.    CHANGE IN CIRCUMSTANCES ....................................... 41

     Section 9.1.  Change of Law ............................................ 41
</TABLE>

                                      -24-
<PAGE>   4

<TABLE>
<S>                                                                           <C>
     Section 9.2.   Unavailability of Deposits or Inability to Ascertain, or
                    Inadequacy of, LIBOR .................................... 42
     Section 9.3.   Increased Cost and Reduced Return ....................... 42
     Section 9.4.   Lending Offices ......................................... 44
     Section 9.5.   Discretion of Bank as to Manner of Funding .............. 44

SECTION 10.    THE AGENT .................................................... 45

     Section 10.1.  Appointment and Authorization of Agent .................. 45
     Section 10.2.  Agent and Affiliates .................................... 45
     Section 10.3.  Action by Agent ......................................... 45
     Section 10.4.  Consultation with Experts ............................... 45
     Section 10.5.  Liability of Agent and Issuing Bank; Credit Decision .... 45
     Section 10.6.  Costs and Expenses ...................................... 46
     Section 10.7.  Indemnity ............................................... 46
     Section 10.8.  Resignation of Agent and Successor Agent ................ 46

SECTION 11.    MISCELLANEOUS ................................................ 47

     Section 11.1.  Withholding Taxes ....................................... 47
     Section 11.2.  No Waiver of Rights ..................................... 48
     Section 11.3.  Non-Business Day ........................................ 48
     Section 11.4.  Documentary Taxes ....................................... 48
     Section 11.5.  Survival of Representations ............................. 49
     Section 11.6.  Survival of Indemnities ................................. 49
     Section 11.7.  Sharing of Set-Off ...................................... 49
     Section 11.8.  Notices ................................................. 49
     Section 11.9.  Counterparts ............................................ 50
     Section 11.10. Successors and Assigns .................................. 50
     Section 11.11. Participants and Note Assignees ......................... 50
     Section 11.12. Assignment of Commitments by Banks ...................... 50
     Section 11.13. Amendments .............................................. 51
     Section 11.14. Headings ................................................ 52
     Section 11.15. Legal Fees and Indemnification .......................... 52
     Section 11.16. Governing Law ........................................... 52
     Section 11.17. Entire Agreement ........................................ 52
Signature Pages ............................................................. 53
</TABLE>


                                      -25-
<PAGE>   5



EXHIBITS

Exhibit A -                 Form of Notice of Payment Request
Exhibit B -                 Form of Note
Exhibit C -                 Form of Opinion of Counsel to Borrower
Exhibit D -                 Form of Compliance Certificate
Schedule 1.2(a) -           Schedule of Revolver Letters of Credit
Schedule 1.2(c) -           Schedule of Bond Letters of Credit
Schedule 5.2 -              Schedule of Subsidiaries
Schedule 5.7 -              Schedule of Taxes
Schedule 5.12 -             Schedule of Environmental Notices
Schedule 5.15 -             Schedule of Outstanding Long Term Debt
Schedule 7.9 -              Schedule of Outstanding Liens
Schedule 7.19 -             Schedule of Restricted Investments
Appendix I -                Form of Standby Letter of Credit Application
Appendix II -               Form of Commercial Letter of Credit Application




                                      -26-
<PAGE>   6



                     AMENDED AND RESTATED CREDIT AGREEMENT

To each of the Banks signatory hereto

Ladies and Gentlemen:

         The undersigned, The Allen Group, Inc., a Delaware corporation (the
"Borrower"), refers to the Credit Agreement dated as of December 18, 1995, as
amended, currently in effect among the Borrower, MARTA Technologies, Inc.
("MARTA"), Bank of Montreal, as Agent, and the Banks party thereto (the
"Original Credit Agreement"). The Borrower and MARTA hereby request that certain
amendments be made to the Original Credit Agreement and for the sake of clarity
and convenience that the Original Credit Agreement be restated in its entirety
as so amended. Each of you is hereinafter referred to as a "Bank", all of you
are hereinafter referred to collectively as the "Banks", and Bank of Montreal in
its capacity as agent for the Banks and any successor pursuant to Section 10.8,
is hereinafter referred to as the "Agent". Bank of America Illinois is the
"Co-Agent" hereunder. This Amended and Restated Credit Agreement amends and
replaces in its entirety the Original Credit Agreement, and from the Effective
Date all references made to the Original Credit Agreement in any Credit Document
or in any other document shall, without more, be deemed to refer to this Amended
and Restated Credit Agreement. This Amended and Restated Credit Agreement shall
become effective as of November 11, 1996 (the "Effective Date"), and supersede
all provisions of the Original Credit Agreement as of such date, upon the
execution of this Agreement by each of the parties hereto and the fulfillment of
the conditions precedent contained in Section 6.1(a)-(e) hereof. By executing
this Amended and Restated Credit, the Banks hereby (a) waive compliance with any
provision of the Original Credit Agreement which would prohibit the sale of the
MARTA Group by the Borrower and (b) consent to the withdrawal of MARTA as a
"Borrower" under the Original Credit Agreement. Subject to Section 6.1(e)
hereof, all "Obligations" outstanding under the Original Credit Agreement on the
Effective Date shall not be extinguished, but shall be payable in accordance
with, and otherwise be governed by, the terms of this Amended and Restated
Credit Agreement applicable to Obligations of such type.

SECTION 1. THE REVOLVING CREDIT FACILITY.

         Section 1.1. Borrowings under the Revolving Credit. Subject to the
terms and conditions hereof, each Bank, by its acceptance hereof, severally
agrees to make a loan or loans (individually a "Loan" and collectively "Loans")
from time to time on a revolving basis to the Borrower in the amount of its
revolving commitment as set forth on the applicable signature page hereto or
pursuant to Section 11.12, subject to any reductions thereof pursuant to the
terms hereof (individually for each Bank its "Commitment" and collectively with
each other Bank's the "Commitments"), prior to the Termination Date. Each
Borrowing of Loans by the Borrower shall be made ratably from the Banks in
proportion to their respective Commitments (for each Bank its "Percentage").
The Borrower may elect that each Borrowing be made available by means of either
Domestic Rate Loans or Eurodollar Loans, which Loans may be repaid and the
principal amount 


                                      -27-
<PAGE>   7



thereof reborrowed prior to the Termination Date, subject to all the terms and
conditions hereof.

         Section 1.2. Letters of Credit. (a) Revolving Credit. Subject to all of
the terms and conditions hereof, the Borrower may avail itself of the
Commitments through letters of credit (the "Revolver Letters of Credit") issued
by Bank of America Illinois (in such capacity as issuer of Revolver Letters of
Credit, the "Revolver Issuer") for the Borrower's account, provided that the
aggregate outstanding undrawn face amount of Revolver Letters of Credit shall
not at any time exceed $20,000,000. Each Revolver Letter of Credit shall be
issued by the Revolver Issuer, but each Bank shall be obligated to reimburse the
Revolver Issuer for its Percentage of the amount of each draft drawn thereunder
and, accordingly, the face amount of each Revolver Letter of Credit shall be
deemed to utilize the Commitments of all Banks pro rata based on each Bank's
Percentage. No Revolver Letter of Credit shall have an expiration date after the
Termination Date (and no time draft eligible to be presented for acceptance, or
other payment undertaking eligible to be incurred, under a Revolver Letter of
Credit may have a maturity date later than the Termination Date). In the event
the Revolver Issuer issues a Revolver Letter of Credit with an expiration date
that automatically extends unless the Revolver Issuer gives notice that the
expiration date will not so extend beyond such Revolver Letter of Credit's then
scheduled expiration date, the Revolver Issuer will give such notice of
non-renewal before the time necessary to prevent such automatic extension if
before such required notice date (i) the expiration date of such Revolver Letter
of Credit if so extended would be after the Termination Date, (ii) the
Commitments have been terminated, or (iii) an Event of Default exists and the
Required Banks have given the Revolver Issuer instructions not to so permit the
extension of the expiration date of such Revolver Letter of Credit. At least
thirty (30) days before the date on which the Revolver Issuer is required to
give notice of the non-renewal of such a Revolver Letter of Credit in order to
prevent its automatic extension, the Revolver Issuer shall give notice to the
Agent of such circumstance and the Agent shall promptly notify each Bank
thereof.

         Notwithstanding anything herein to the contrary, each letter of credit
described on Schedule 1.2(a) attached hereto shall constitute a "Revolver Letter
of Credit" herein for all purposes of this Agreement to the same extent, and
with the same force and effect, as if such letter of credit had been issued at
the request of the Borrower under this Agreement.

         (b) Applications for Revolver Letters of Credit. At any time before the
Termination Date, the Revolver Issuer agrees that at the Borrower's request it
shall issue one or more Revolver Letters of Credit, in a form satisfactory to
the Revolver Issuer, with expiration dates no later than the Termination Date,
in an aggregate face amount as set forth above, upon the receipt of a duly
executed application for the relevant Revolver Letter of Credit in the form
customarily prescribed by the Revolver Issuer for a letter of credit of the
type, whether standby or commercial, requested (each an "Application"). The
current forms of the Revolver Issuer's Applications are attached as Appendices I
and II hereto. The Revolver Issuer shall provide the Borrower and the other
Banks with copies of any new forms of Applications that may, from time to time,
be adopted by the Revolver Issuer. Notwithstanding anything contained in any
Application to the contrary (i) the Borrower 



                                      -28-
<PAGE>   8

shall pay fees in connection with each Revolver Letter of Credit as set forth in
Section 2.1(b) hereof, (ii) prior to the occurrence of an Event of Default,
neither the Revolver Issuer nor the Agent will call for the funding by the
Borrower of any amount under a Revolver Letter of Credit, or any other
collateral security for obligations of the Borrower under an Application, prior
to being presented with a drawing thereunder, (iii) upon the termination of the
Commitments, the full amount then available for drawing under all outstanding
Revolver Letters of Credit shall be immediately due and payable in the manner
described in Section 8.4 hereof, and (iv) in the event the Revolver Issuer is
not timely reimbursed for the amount of any drawing under a Revolver Letter of
Credit on the date such drawing is paid, the Borrower's obligation to reimburse
the Revolver Issuer for the amount of such drawing shall bear interest (which
the Borrower hereby promises to pay) from and after the date such drawing is
paid at a rate per annum equal to the rate set forth in Section 1.9(a) hereof.
The Revolver Issuer also agrees to issue amendments to any Revolver Letter(s) of
Credit increasing the amount, or extending the expiration date, thereof at the
Borrower's request subject to the conditions of Section 6 and the other terms of
this Section 1.2. Before issuing, or increasing the amount of, any Revolver
Letter of Credit under this Section 1.2 the Revolver Issuer shall notify the
Agent of the proposed amount of the Revolver Letter of Credit, or of the
proposed increase thereof, and the Agent shall determine and notify the Revolver
Issuer whether such amount would exceed any restriction on the aggregate face
amount of Revolver Letters of Credit set forth in Section 6.2(d) or (e) hereof.

         (c) Bond Letters of Credit. Dresdner Bank AG, New York Branch (in such
capacity, the "Bond Letter of Credit Issuer") has issued and has outstanding
four (4) separate letters of credit (the "Bond Letters of Credit" and each
individually a "Bond Letter of Credit") in the aggregate face amount of
$15,912,603 to support payments on certain industrial revenue bonds, as more
fully identified on Schedule 1.2(c) hereto. Each Bank agrees to participate in
such outstanding Bond Letters of Credit in accordance with its Percentage on the
terms applicable to participations in Revolver Letters of Credit hereunder.
Except to the extent inconsistent with the terms hereof (in which case the
inconsistent terms herein shall govern), the provisions of the four (4)
Reimbursement Agreements applicable to such Letters of Credit, as identified on
Schedule 1.2(c) hereto, shall continue to govern such Bond Letters of Credit.
Notwithstanding anything to the contrary in any Reimbursement Agreement, the
fees payable in connection with each Bond Letter of Credit to be shared with the
Banks shall accrue from the date hereof at the rate provided in Section 2.1(b)
hereof. "Bond Letters of Credit" and "Revolver Letters of Credit" are
collectively hereinafter sometimes referred to as "Letters of Credit" and each
is hereinafter sometimes referred to as a "Letter of Credit".

         (d) Borrower's Reimbursement Obligations. Subject to Section 1.2(b) and
(c) hereof, the obligation of the Borrower to reimburse the Revolver Issuer or
Bond Letter of Credit Issuer (each an "Issuing Bank"), as applicable, for all
drawings under a Letter of Credit it has issued (a "Reimbursement Obligation")
shall be governed by the Application or Reimbursement Agreement, as applicable,
for such Letter of Credit except that reimbursement of drawings under the
Revolver Letters of Credit shall be made to the Agent, not the Revolver Issuer,
by no later than 12:00 Noon (Chicago time) on the date when such 



                                      -29-
<PAGE>   9

drawing is paid in immediately available funds at the Agent's principal office
in Chicago, Illinois, and the Agent shall promptly thereafter remit such payment
in like funds as received to the Revolver Issuer. If the Borrower does not make
any such reimbursement payment on the date due and the Participating Banks fund
their participations therein in the manner set forth in Section 1.2(e) below,
then all payments thereafter received by the Agent in discharge of any of the
relevant Reimbursement Obligations shall be distributed ratably to each Bank
hereunder in accordance with its Percentage. The Bond Letter of Credit Issuer
will notify the Agent no later than the Business Day after the due date of any
Reimbursement Obligation if it has not received payment of such Reimbursement
Obligation and promptly after it becomes aware of any other "default" or "event
of default" under a Reimbursement Agreement. The Agent shall promptly forward to
each Bank any such notice it receives from the Bond Letter of Credit Issuer.

         The Borrower's reimbursement obligations under this Section 1.2(d) and
each Application and Reimbursement Agreement shall be absolute, unconditional
and irrevocable, and shall be performed strictly in accordance with the terms of
this Agreement, the Applications, and the Reimbursement Agreements, under all
circumstances whatsoever, including without limitation the following
circumstances:

                  (i) any lack of validity or enforceability of any L/C
         Document; 

                  (ii) the existence of any claim, set-off, defense or other
         right that the Borrower may have at any time against a beneficiary of a
         Letter of Credit (or any Person for whom such a beneficiary may be
         acting), the Agent, the Issuing Bank, any other Bank or any other
         Person, whether in connection with this Agreement, another L/C Document
         or any unrelated transaction;

                  (iii) any statement or any other document presented under a
         Letter of Credit proving to be forged, fraudulent, invalid or
         insufficient in any respect or any statement therein being untrue or
         inaccurate in any respect whatsoever;

                  (iv) payment by the Issuing Bank under a Letter of Credit
         against presentation to the Issuing Bank of a draft or certificate that
         does not comply with the terms of the Letter of Credit, provided that
         the Issuing Bank's determination that documents presented under the
         Letter of Credit comply with the terms thereof shall not have
         constituted gross negligence or willful misconduct of the Issuing Bank;
         or

                  (v) any other act or omission to act or delay of any kind by
         the Agent, the Issuing Bank, any other Bank or any other Person or any
         other event or circumstance whatsoever that might, but for the
         provisions of this Section 1.2(d), constitute a legal or equitable
         discharge of the Borrower's obligations hereunder.

         (e) The Participating Interests. Each Bank (other than the relevant
Issuing Bank), by its acceptance hereof, severally agrees to purchase from each
Issuing Bank, and each Issuing Bank hereby agrees to sell to each such Bank (a
"Participating Bank"), an undivided percentage participating interest, to the
extent of its Percentage, in each Letter of Credit



                                      -30-
<PAGE>   10

issued by, and Reimbursement Obligation owed to, such Issuing Bank. Upon any
failure by the Borrower to pay any Reimbursement Obligation at the time required
on the date the related drawing is paid, as set forth in Section 1.2(d) above,
or in the event the Issuing Bank is required at any time to return to the
Borrower or to a trustee, receiver, liquidator, custodian or other similar
official any portion of any payment by the Borrower of any Reimbursement
Obligation, each Participating Bank shall, not later than the Business Day it
receives a certificate in the form of Exhibit A hereto from the Issuing Bank
(given directly or through the Agent) to such effect, if such certificate is
received before 1:00 P.M. (Chicago time), or not later than the following
Business Day, if such certificate is received after such time, pay to the Agent
for the account of the Issuing Bank an amount equal to its Percentage of such
unpaid or recaptured Reimbursement Obligation together with interest on such
amount accrued from the date the related payment was made by the Issuing Bank to
the date of such payment by such Participating Bank at a rate per annum equal to
(i) from the date the related payment was made by the Issuing Bank to the date
two (2) Business Days after payment by such Participating Bank is due hereunder,
the Federal Funds Rate for each such day and (ii) from the date two (2) Business
Days after such payment is due from such Participating Bank to the date such
payment is made by such Participating Bank, the Domestic Rate in effect for each
such day. Each such Participating Bank shall thereafter be entitled to receive
its Percentage of each payment received in respect of the relevant Reimbursement
Obligation and of interest paid thereon, with the Issuing Bank retaining its
Percentage.

         The several obligations of the Participating Banks to each Issuing Bank
under this Section 1.2 shall be absolute, irrevocable and unconditional under
any and all circumstances whatsoever (except, without limiting the Borrower's
unconditional obligation under Section 1.2(d) to pay all Reimbursement
Obligations, to the extent the gross negligence or willful misconduct of the
relevant Issuing Bank relieves the Borrower of its obligation to pay a
Reimbursement Obligation) and shall not be subject to any set-off, counterclaim
or defense to payment which any Participating Bank may have or have had against
the Borrower, the Issuing Bank, any other Bank or any other Person whatsoever.
Without limiting the generality of the foregoing, such obligations shall not be
affected by any Default or Event of Default or by any reduction or termination
of any Commitment of any Bank and each payment by a Participating Bank under
this Section 1.2 shall be made without any offset, abatement, withholding or
reduction whatsoever. The Agent shall be entitled to offset amounts received for
the account of Banks under this Agreement against unpaid amounts due from Banks
hereunder (whether as fundings of participations, indemnities or otherwise) but
shall not be entitled to offset against amounts owed to the Agent by any Bank
arising outside this Agreement.

         (f) Indemnification. The Participating Banks shall, to the extent of
their respective Percentages, indemnify each Issuing Bank (to the extent not
reimbursed by the Borrower) against any cost, expense (including counsel fees
and disbursements), claim, demand, action, loss or liability (except such as
result from the Issuing Bank's gross negligence or willful misconduct) that the
Issuing Bank may suffer or incur in connection with any Letter of Credit. The
obligations of the Participating Banks under this Section 1.2(f) and all other


                                      -31-
<PAGE>   11

parts of this Section 1.2 shall survive the termination of this Agreement and of
any relevant Application or Reimbursement Agreement.

         Section 1.3. Applicable Interest Rates. (a) Domestic Rate Loans. Each
Domestic Rate Loan made by a Bank shall bear interest (computed on the basis of
a year of 365 or 366 days, as the case may be, and actual days elapsed) each day
on the unpaid principal amount thereof from the date such Loan is made until
maturity (whether by acceleration or otherwise) at a rate per annum equal to the
Domestic Rate applicable for such day, payable on the last day of the applicable
Interest Period and at maturity (whether by acceleration or otherwise).

         "Domestic Rate" means for any day the greater of:

         (i) the rate of interest then most recently announced by Bank of
America Illinois at Chicago, Illinois as its reference rate, with any change in
the Domestic Rate resulting from a change in said announced reference rate to be
effective as of the date of the relevant change in said reference rate; and

         (ii) the sum of (x) the rate per annum (rounded upward, if necessary,
to the nearest 1/100th of 1%) equal to the weighted average of the rates on
overnight Federal funds transactions with member banks of the Federal Reserve
System arranged by Federal funds brokers on such day, as published by the
Federal Reserve Bank of New York on the Business Day next succeeding such day,
provided that (i) if such day is not a Business Day, the rate for such day shall
be such rate on such transactions on the immediately preceding Business Day as
so published on the next succeeding Business Day, and (ii) if no such rate is so
published on any such next succeeding Business Day, the rate for such day shall
be the average of the rates quoted to the Agent by two or more New York or
Chicago Federal funds brokers on such day for such transactions as determined by
the Agent, plus (y) 1/2 of 1% (0.50%).

         (b) Eurodollar Loans. Each Eurodollar Loan made by a Bank shall bear
interest (computed on the basis of a year of 360 days and actual days elapsed)
each day on the unpaid principal amount thereof from the date such Loan is made
until maturity (whether by acceleration or otherwise) at a rate per annum equal
to the sum of the Eurodollar Margin plus the Adjusted LIBOR applicable to such
Loan, payable on the last day of the applicable Interest Period and at maturity
(whether by acceleration or otherwise), and, if the applicable Interest Period
is longer than three months, on the date occurring every three months after the
date such Loan is made.

         "Adjusted LIBOR" means a rate per annum (rounded upward, if necessary,
to the nearest 1/100 of 1%) determined in accordance with the following formula:

                                                LIBOR
                                 ------------------------------------
                Adjusted LIBOR = 100% - Eurodollar Reserve Percentage



                                      -32-
<PAGE>   12

         "LIBOR" means, with respect to an Interest Period for a Borrowing of
Eurodollar Loans, the rate of interest per annum, as determined by the Agent
(rounded upwards, if necessary, to the nearest whole multiple of 1/16 of 1%), at
which deposits of United States Dollars in immediately available and freely
transferable funds are offered to the Agent at 11:00 A.M. (London, England time)
two Business Days prior to the commencement of such Interest Period by major
banks in the interbank eurodollar market for a period equal to such Interest
Period and in an amount approximately equal to the principal amount of the
Eurodollar Loan scheduled to be made by the Agent as part of such Borrowing.

         "Eurodollar Reserve Percentage" means, for an Interest Period for a
Borrowing of Eurodollar Loans, the daily average of the maximum rate at which
reserves, if any, (including, without limitation, any supplemental, marginal and
emergency reserves) are imposed during such Interest Period by the Board of
Governors of the Federal Reserve System (or any successor) on "eurocurrency
liabilities", as defined in such Board's Regulation D (or in respect of any
other category of liabilities that includes deposits by reference to which the
interest rate on Eurodollar Loans is determined or any category of extension of
credit or other assets that include loans by non-United States offices of any
Bank to United States residents), subject to any amendments of such reserve
requirement by such Board or its successor, taking into account any transitional
adjustments thereto. For purposes of this definition, the Eurodollar Loans shall
be deemed to be eurocurrency liabilities as defined in Regulation D without
benefit or credit for any prorations, exemptions or offsets under Regulation D.

         "Eurodollar Margin" means, until the fir t Pricing Change Date occurs,
0.375% per annum and, thereafter, from one Pricing Change Date (the "Pricing
Date") to the next a rate per annum determined based on the Total Funded Debt to
Cash Flow Ratio for such Pricing Date in accordance with the following schedule:

<TABLE>
<CAPTION>
Debt to Cash Flow
-----------------
Test for such Pricing Date:                                          Eurodollar Margin:
---------------------------                                          ------------------
<S>                                                                        <C>  
LEVEL I.  Total Funded Debt to Cash Flow Ratio
less than 1.00 to 1.00                                                     0.25%

LEVEL II. Level I not achieved, but Total Funded 
Debt to Cash Flow Ratio less than 2.00 to 1.00                             0.375%

LEVEL III. Levels I and II not achieved, 
but Total Funded Debt to Cash Flow Ratio 
less than 3.00 to 1.00                                                     0.55%

LEVEL IV. Levels I, II and III not achieved, 
but Total Funded Debt to Cash Flow Ratio 
less than 4.00 to 1.00                                                     1.00%

LEVEL V.  None of Levels I-IV achieved.                                    1.50%
</TABLE>



                                      -33-
<PAGE>   13

         (c) Rate Determinations. The Agent shall determine each interest rate
applicable to the Loans hereunder, and its determination thereof shall be
conclusive and binding except in the case of manifest error or willful
misconduct. Bank of America Illinois shall notify the Agent of all changes in
its reference rate described in clause (i) of the definition of Domestic Rate.

         Section 1.4. Minimum Borrowing Amounts. Each Borrowing of Domestic Rate
Loans shall be in an amount not less than $1,000,000, or any larger amount that
is an integral multiple of $100,000, and each Borrowing of Eurodollar Loans
shall be in an amount not less than $5,000,000, or any larger amount that is an
integral multiple of $500,000.

         Section 1.5. Manner of Borrowing. (a) Notice to the Agent. The Borrower
shall give telephonic, telex or telecopy notice to the Agent (which notice shall
be irrevocable once given and, if by telephone, shall be promptly confirmed in
writing) (i) by no later than 2:00 P.M. (Chicago time) on the date at least
three (3) Business Days prior to the date of each requested Borrowing of
Eurodollar Loans, and (ii) by no later than 9:00 A.M. (Chicago time) on the date
of each requested Borrowing of Domestic Rate Loans. Each such notice from the
Borrower shall specify the date of the requested Borrowing (which shall be a
Business Day), the amount of the requested Borrowing, the type of Loans to
comprise such Borrowing, and, if such Borrowing is to be comprised of Eurodollar
Loans, the Interest Period selected by the Borrower to be applicable thereto.
The Borrower agrees that the Agent may rely on any such telephonic, telex or
telecopy notice given by any person it in good faith believes is an Authorized
Representative without the necessity of independent investigation and, in the
event any notice by such means conflicts with the written confirmation, such
notice shall govern if the Agent has acted in reliance thereon.

         (b) Notice to the Banks. The Agent shall give prompt telephonic, telex
or telecopy notice to each of the Banks of any borrowing request received
pursuant to Section 1.5(a) above and, if such notice requests the Banks to make
Eurodollar Loans, the Agent shall give notice to the Borrower and each of the
Banks by like means of the interest rate applicable thereto (but, if such notice
is given by telephone, the Agent shall confirm such rate in writing) promptly
after the Agent has made such determination.

         (c) Borrower's Failure to Notify. In the event the Borrower fails to
give notice pursuant to Section 1.5(a) above of the reborrowing of the principal
amount of any maturing Borrowing or of a Borrowing equal to the amount of a
Reimbursement Obligation owed on a Revolver Letter of Credit and has not
notified the Agent by 10:00 A.M. (Chicago time) on the day such Borrowing
matures or such Reimbursement Obligation becomes due that it intends to repay
such Borrowing or pay such Reimbursement Obligation through funds not borrowed
under this Agreement, the Borrower shall be deemed to have requested a Borrowing
of Domestic Rate Loans on such day in the amount of the maturing Borrowing of
Loans or of the Reimbursement Obligation then due, subject to Section 6.2
hereof, which Borrowing shall be applied to pay the maturing Borrowing or the
Reimbursement Obligation then due. The Agent shall give prompt telephonic, telex
or telecopy notice to each Bank of any such deemed borrowing request.



                                      -34-
<PAGE>   14

         (d) Disbursement of Loans. Not later than 12:00 noon (Chicago time) on
the date of any Borrowing of Loans, subject to Section 6 hereof, each Bank shall
make available its Loan in funds immediately available in Chicago, Illinois at
the principal office of the Agent, except to the extent such Borrowing is a
reborrowing, in whole or in part, of the principal amount of a maturing
Borrowing of Loans (a "Refunding Borrowing"), in which case each Bank shall
record the Loan made by it as a part of such Refunding Borrowing on its books
and records or on a schedule to its appropriate Note, as provided in Section
1.10(b) hereof, and shall effect the repayment, in whole or in part, as
appropriate, of its maturing Loan through the proceeds of such new Loan. The
Agent shall make the proceeds of each non-Refunding Borrowing available to the
Borrower at the Agent's principal office in Chicago, Illinois.

         (e) Agent Reliance on Bank Funding. Unless the Agent shall have been
notified by a Bank prior to (or, in the case of a Borrowing of Domestic Rate
Loans, by 11:00 A.M. (Chicago time) on) the date on which such Bank is scheduled
to make payment to the Agent of the proceeds of a Loan (which notice shall be
effective upon receipt) that such Bank does not intend to make such payment, the
Agent may assume that such Bank has made such payment when due and the Agent may
in reliance upon such assumption (but shall not be required to) make available
to the Borrower the proceeds of the Loan to be made by such Bank and, if any
Bank has not in fact made such payment to the Agent, such Bank shall, on demand,
pay to the Agent the amount made available to the Borrower attributable to such
Bank together with interest thereon in respect of each day during the period
commencing on the date such amount was made available to the Borrower and ending
on (but excluding) the date such Bank pays such amount to the Agent at a rate
per annum equal to the Federal Funds Rate. If such amount is not received from
such Bank by the Agent immediately upon demand, the Borrower will, on demand,
repay to the Agent the proceeds of the Loan attributable to such Bank with
interest thereon at a rate per annum equal to the interest rate applicable to
the relevant Loan, but without such payment being considered a payment or
prepayment of a Loan, so that the Borrower will have no liability under Section
1.11 hereof with respect to such payment.

         Section 1.6. Interest Periods. As provided in Section 1.5(a) hereof, at
the time of each request for the Borrowing of Eurodollar Loans hereunder the
Borrower shall select an Interest Period applicable to such Loans from among the
available options. The term "Interest Period" means the period commencing on the
date a Borrowing of Loans is made and ending on the date, (a) in the case of
Domestic Rate Loans, that is the last day of the calendar quarter (i.e. March
31, June 30, September 30 or December 31) during which such Borrowing is made;
and (b) in the case of Eurodollar Loans 1, 2, 3, 4, 5 or 6 (or, if each Bank
confirms to the Agent it has available funding for Eurodollar Loans for such a
period, 9 or 12) months thereafter; provided, however, that:

                  (a) any Interest Period for a Borrowing of Domestic Rate Loans
         commencing during the calendar quarter in which the Termination Date
         occurs shall end on the Termination Date;



                                      -35-
<PAGE>   15

                  (b) with respect to any Borrowing of Eurodollar Loans, the
         Borrower may not select an Interest Period that extends beyond the
         Termination Date;

                  (c) whenever the last day of any Interest Period would
         otherwise be a day that is not a Business Day, the last day of such
         Interest Period shall be extended to the next succeeding Business Day,
         provided that, in the case of an Interest Period for a Borrowing of
         Eurodollar Loans, if such extension would cause the last day of such
         Interest Period to occur in the following calendar month, the last day
         of such Interest Period shall be the immediately preceding Business
         Day; and

                  (d) for purposes of determining the Interest Period for a
         Borrowing of Eurodollar Loans, a month means a period starting on one
         day in a calendar month and ending on the numerically corresponding day
         in the next calendar month; provided, however, that if there is no
         numerically corresponding day in the month in which such an Interest
         Period is to end or if such an Interest Period begins on the last
         Business Day of a calendar month, then such Interest Period shall end
         on the last Business Day of the calendar month in which such Interest
         Period is to end.

         Section 1.7. Maturity of Loans. Each Loan shall mature and become due
and payable by the Borrower on the last day of the Interest Period applicable
thereto or, if earlier, on the Termination Date.

         Section 1.8. Optional Prepayments. The Borrower shall have the
privilege of prepaying without premium or penalty and in whole or in part (but,
if in part, then: (i) in an amount not less than $1,000,000 for Domestic Rate
Loans and $5,000,000 for Eurodollar Loans, and in integral multiples of
$100,000, and (ii) in an amount such that the minimum amount required pursuant
to Section 1.4 hereof remains outstanding), any Borrowing of Loans by the
Borrower at any time upon one (1) Business Day's (or, in the case of Eurodollar
Loans, three (3) Business Days') prior notice (which shall be irrevocable) to
the Agent (which shall advise each Bank thereof promptly thereafter), such
prepayment to be made by the payment of the principal amount to be prepaid and
accrued interest thereon to the date fixed for prepayment and, in the case of
Eurodollar Loans, any compensation payable under Section 1.11 hereof.

             Section 1.9. Default Rate. If any payment of principal on any Loan
is not made when due (whether by acceleration or otherwise), such Loan shall
bear interest (computed on the basis of a year of 360 days and actual days
elapsed) from the date such payment was due until paid in full, payable by the
Borrower on demand, at a rate per annum equal to:

                  (a) with respect to any Domestic Rate Loan, the sum of two
         percent (2%) per annum plus the Domestic Rate from time to time in
         effect; and

                  (b) with respect to any Eurodollar Loan, the sum of two
         percent (2%) per annum plus the rate of interest in effect thereon at
         the time of such default until the end of the Interest Period
         applicable thereto and, thereafter, at a rate per annum equal



                                      -36-
<PAGE>   16

         to the sum of two percent (2%) per annum plus the Domestic Rate from
         time to time in effect;

it being understood that the repayment of a maturing Borrowing with the proceeds
of a Refunding Borrowing on the date such maturing Borrowing is due constitutes,
to the extent of such Refunding Borrowing, payment of the maturing Borrowing
when due.

         Section 1.10. The Notes. (a) The Loans made by a Bank shall be
evidenced by a single promissory note of the Borrower in the form of Exhibit B
hereto (each a "Note" and collectively the "Notes"). Each such Note shall be
dated the date of issuance, shall be payable to the order of the relevant Bank
in the principal amount of its Commitment, and shall otherwise be in the form of
Exhibit B hereto.

         (b) Each Bank shall record on its books and records or on a schedule to
its Note the amount of each Loan made by it to the Borrower, the Interest Period
thereof, all payments of principal and interest and the principal balance from
time to time outstanding thereon, the type of such Loan and, if a Eurodollar
Loan, the interest rate applicable thereto; provided that prior to the transfer
of any Note all such amounts shall be recorded on a schedule to such Note. The
record thereof, whether shown on such books and records of a Bank or on a
schedule to any Note, shall be prima facie evidence as to all such amounts;
provided, however, that the failure of any Bank to record any of the foregoing
or any error in any such record shall not limit or otherwise affect the
obligation of the Borrower to repay all Loans made to it hereunder together with
accrued interest thereon. At the request of any Bank and upon such Bank
tendering to the Borrower the Note to be replaced, the Borrower shall furnish a
new Note to such Bank to replace any outstanding Note issued by it and at such
time the first notation appearing on a schedule on the reverse side of, or
attached to, such Note shall set forth the aggregate unpaid principal amount of
all Loans, if any, then outstanding thereon.

         Section 1.11. Funding Indemnity. In the event any Bank shall incur any
loss, cost or expense (including, without limitation, any loss of profit and any
loss, cost, expense or premium incurred by reason of the liquidation or
re-employment of deposits or other funds acquired by such Bank to fund or
maintain any Eurodollar Loan or the relending or reinvesting of such deposits or
amounts paid or prepaid to such Bank) as a result of:

                  (a) any payment or prepayment of a Eurodollar Loan on a date
         other than the last day of its Interest Period,

                  (b) any failure (because of a failure to meet the conditions
         of Section 6 or otherwise) by the Borrower to borrow a Eurodollar Loan
         on the date specified in a notice given pursuant to Section 1.5(a)
         hereof,

                  (c) any failure, for any reason, to prepay a Eurodollar Loan
         after giving notice thereof under Section 1.8 hereof, or

                  (d) the occurrence of any Event of Default hereunder,



                                      -37-
<PAGE>   17

then, upon the demand of such Bank, the Borrower shall pay to such Bank such
amount as will reimburse such Bank for such loss, cost or expense. If any Bank
makes such a claim for compensation, it shall provide to the Borrower a
certificate executed by an officer of such Bank setting forth the amount of such
loss, cost or expense in reasonable detail (including an explanation of the
basis for and the computation of such loss, cost or expense), and the amounts
shown on such certificate shall be conclusive and binding absent manifest error.

         Section 1.12. Optional Commitment Terminations. The Borrower shall have
the right at any time and from time to time, upon five (5) Business Days' prior
written notice to the Agent, to terminate without premium or penalty, in whole
or in part, the Commitments, any partial termination to be in an amount not less
than $5,000,000 or any larger amount that is an integral multiple of $1,000,000
and to reduce ratably the respective Commitments of each Bank; provided that the
Commitments may not be reduced to an amount less than the Revolving Obligations
then outstanding. Any termination of Commitments pursuant to this Section 1.12
may not be reinstated.

SECTION 2. FEES AND EXTENSIONS.

         Section 2.1. Fees. (a) Revolving Credit. For the period from the
Effective Date to and including the Termination Date, the Borrower shall pay to
the Agent for the ratable account of the Banks, based on their Percentages, a
commitment fee accruing at the rate of 0.15% per annum until the first Pricing
Change Date and thereafter from one Pricing Change Date (the "Pricing Date") to
the next at a rate per annum (the "Commitment Fee Rate") determined based on the
Total Funded Debt to Cash Flow Ratio for such Pricing Date in accordance with
the following schedule (computed on a basis of a year of 365 or 366 days, as the
case may be, and actual days elapsed), on the average daily unused amount of the
Commitments, such fees being payable in arrears on December 31, 1996, on the
last day of each calendar quarter thereafter and on the Termination Date, unless
the Commitments are terminated in whole on an earlier date, in which event the
commitment fee for the period to but not including the date of such termination
shall be paid in whole on the date of such termination:

<TABLE>
<CAPTION>
Debt to Cash Flow
-----------------
Test for such Pricing Date:                                        Commitment Fee Rate:
---------------------------                                        --------------------
<S>                                                                        <C>   
LEVEL I.  Total Funded Debt to Cash Flow Ratio
less than 1.00 to 1.00                                                     0.125%

LEVEL II. Level I not achieved, but Total Funded 
Debt to Cash Flow Ratio less than 2.00 to 1.00                             0.15%

LEVEL III. Levels I and II not achieved, 
but Total Funded Debt to Cash Flow Ratio 
less than 3.50 to 1.00                                                     0.20%
</TABLE>



                                      -38-
<PAGE>   18

<TABLE>
<S>                                                                        <C>   
LEVEL IV. Levels I, II and III not achieved, 
but Total Funded Debt to Cash Flow Ratio 
less than 4.00 to 1.00                                                     0.25%

LEVEL V.  None of Levels I-IV achieved.                                    0.50%
</TABLE>

         (b) Letters of Credit. The Borrower shall pay to the Agent for the
ratable benefit of the Banks a fee for each Letter of Credit at a rate per annum
equal to the Eurodollar Margin in effect at the time payment of such fee is due
applied to the face amount of such Letter of Credit, payable quarterly in
advance on the date of issuance of the Letter of Credit (and separately on the
date of any increase in the amount of the Letter of Credit for the amount of
such increase) for the period from such date to the end of the calendar quarter
in which such date falls and thereafter on the last day of such calendar quarter
and of each subsequent calendar quarter, based on the scheduled expiration date
of such Letter of Credit.

         (c) Closing. On the date hereof, the Borrower shall pay to the Agent a
closing fee for the ratable benefit of the Banks, based on their Percentages,
equal to one-tenth of one percent (0.10%) of the original Commitments plus the
face amount of the Bond Letters of Credit then outstanding.

         (d) Agent. The Borrower shall pay to the Agent the fees agreed to
between the Agent and the Borrower.

         Section 2.2. Extension of Termination Date. Between April 1 and April
30, 1997 (and between April 1 and April 30 of each year thereafter before the
Termination Date) the Borrower may request in a written notice to the Agent that
the Termination Date then in effect be extended by one (1) year. The Agent will
promptly inform the Banks of any such request and each Bank shall notify the
Agent in writing by June 30 of the applicable year whether it agrees to such
extension (each such Bank agreeing to such extension being a "Consenting Bank").
In the event that a Bank shall fail timely to so notify the Agent whether it
agrees to such extension, such Bank shall be deemed to have refused to grant the
requested extension. Upon receipt by the Agent of the consent to such extension
of all the Banks by June 30 of the applicable year, the Termination Date shall
be automatically extended an additional one (1) year. If the Required Banks
consent to such extension but fewer than all the Banks so consent, and if the
Borrower still desires to extend the Termination Date, it may seek to:

                  (a) Reallocate the Commitments among the Consenting Banks,
         subject to the approval of each Consenting Bank whose Commitment would
         be increased by such reallocation and that each Bank's Commitment
         represents the same Percentage of the Commitments; or

                  (b) Substitute new Banks, subject to the approval of all the
         Consenting Banks, such substitution to take place in a manner and at a
         time reasonably established by the Borrower and the Agent.



                                      -39-
<PAGE>   19

If the Borrower and the relevant Banks do not agree pursuant to (a) or (b)
above, the Termination Date shall take place as scheduled.

SECTION 3. PLACE AND APPLICATION OF PAYMENTS.

         Section 3.1. Place and Application of Payments. All payments of
principal of and interest on the Loans and the Reimbursement Obligations (other
than Reimbursement Obligations under the Bond Letters of Credit, which remain
subject to their Reimbursement Agreements, as provided in Section 1.2(c)), and
of all other amounts payable by the Borrower under this Agreement, shall be made
by the Borrower to the Agent by no later than 12:00 noon (Chicago time) at the
principal office of the Agent in Chicago, Illinois (or such other location in
the State of Illinois as the Agent may designate to the Borrower) for the
benefit of the Banks. All such payments shall be made in lawful money of the
United States of America, in immediately available funds at the place of
payment, without setoff or counterclaim. The Agent will promptly thereafter
cause to be distributed like funds relating to the payment of fees and of
principal or interest on Loans and on Reimbursement Obligations in which the
Banks have purchased participating interests ratably to the Banks, and like
funds relating to the payment of any other amount payable to any Bank (including
the Issuing Bank) to such Person, in each case to be applied in accordance with
the terms of this Agreement. 

SECTION 4. DEFINITIONS; INTERPRETATION.

         Section 4.1. Definitions. The following terms when used herein have the
following meanings:

         "Adjusted Consolidated Net Worth" means Consolidated Net Worth plus the
Subordinated Debt Amount minus Redeemable Preferred Stock included in
Consolidated Net Worth.

         "Adjusted LIBOR" is defined in Section 1.3(b) hereof.

         "Affiliate" means any Person (i) which directly or i directly through
one or more intermediaries controls, or is controlled by, or is under common
control with, the Borrower, (ii) which beneficially owns 20% or more of any
class of the Voting Stock of the Borrower or (iii) 20% or more of the Voting
Stock of which is beneficially owned by the Borrower or a Subsidiary. The term
"control" means the possession, directly or indirectly, of the power to direct
or cause the direction of the management and policies of a Person, whether
through the ownership of Voting Stock, by contract or otherwise.

         "Agent" means Bank of Montreal and any successor pursuant to Section
10.8 hereof.

         "Application" is defined in Section 1.2(b) hereof.



                                      -40-
<PAGE>   20

         "Authorized Representative" means, for the Borrower, each person shown
on the list of officers provided by the Borr wer pursuant to Section 6.1(d)
hereof, or on any updated such list provided by the Borrower to the Agent, or
any further or different officer of the Borrower so named by any Authorized
Representative in a written notice to the Agent.

         "Bank" means each bank signatory h reto, including each Issuing Bank,
and any assignee of a Bank pursuant to Section 12.12 hereof.

         "Bond Document" means any document or instrument entered into in
connection with any Bonds and any amendment or supplement thereto (including,
without limitation, all "Related Documents" as defined in any Reimbursement
Agreement).

         "Bond Letter of Credit Issuer" is defined in Section 1.2(d) hereof.

         "Bond Letters of Credit" is defined in Section 1.2 hereof.

         "Bonds" means the bond issues identified on Schedule 1.2(c).

         "Borrower" is defined in the introductory paragraph hereof.

         "Borrowing" means the total of Loans of a single type made by one or
more Banks to the Borrower on a single date and for a single Interest Period.
Borrowings are made ratably from each of the Banks according to their
Percentages.

         "Business Day" means any day other than Saturday or Sunday on which
banks are not authorized or required to close in Chicago, Illinois or New York,
New York and, if the applicable Business Day relates to the borrowing or payment
of a Eurodollar Loan, on which banks are dealing in United States Dollar
deposits in the interbank market in London, England.

         "Capital Lease" means any lease of Property which in accordance with
GAAP would be required to be capitalized on the balance sheet of the lessee.

         "Capitalized Lease Obligations" means, for any Person, the amount of
the li bility as shown on the balance sheet of such Person in respect of Capital
Leases as determined at any date in accordance with GAAP.

         "Change of Control" is defined in Section 8.1(l) hereof.

         "Co-Agent" means Bank of America Illinois.

         "Code" means the Internal Revenue Code of 1986, as amended.

         "Commitments" is defined in Section 1.1 hereof.



                                      -41-
<PAGE>   21

         "Compliance Certificate" means a certificate in the form of Exhibit D
hereto delivered by the Borrower pursuant to Section 7.6(a) hereof.

         "Consenting Bank" is defined in Section 2.2 hereof.

         "Consolidated Net Worth" means the excess of total assets of the
Borrower and its Subsidiaries on a consolidated basis over total liabilities of
the Borrower and its Subsidiaries on a consolidated basis, total assets and
total liabilities each to be determined in accordance with GAAP.

         "Consolidated Tangible Net Worth" means Consolidated Net Worth minus
(to the extent included in such amount) all Redeemable Preferred Stock minus all
assets which would be classified as intangible assets under GAAP.

         "Contingent Obligations" means, as to any Person, all obligations of
such Person on or with respect to Guaranties, and all other obligations of such
Person that are not Debt but that must be disclosed in the financial statements
of such Person as to amount in accordance with GAAP; provided, however, that (i)
a Contingent Obligation that duplicates or is included in Total Funded Debt
shall not be considered a Contingent Obligation hereunder to the extent such
Contingent Obligation or the other Debt it supports is included in Total Funded
Debt and (ii) the Maryland Surety Bonds shall not be considered Contingent
Obligations hereunder.

         "Contractual Obligations" means, as to any Person, any provision of any
security issued by such Person or of any agreement, instrument or undertaking to
which such Person is a party or by which it or any of its property is bound.

         "Credit Documents" means this Agreement, the Notes, the Applications,
the Reimbursement Agreements, the Bond Documents and the Letters of Credit.

         "Credit Event" means the making of any Loan or the issuance of, or
extension of the expiration date or increase in the amount of, any Letter of
Credit.

         "Debt" means, for the Borrower and each Subsidiary (without
duplication), all (i) obligations of such Person for borrowed money, (ii)
obligations of such Person representing the deferred purchase price of property
or services other than accounts payable arising in the ordinary course of
business on terms customary in the trade, (iii) obligations of such Person
evidenced by bonds, debentures, notes, acceptances, or other similar
instruments, (iv) Capitalized Lease Obligations of such Person, (v) obligations
of the type described in clauses (i)-(iv) above secured by Liens or payable out
of the proceeds or production from Property now or hereafter owned or acquired
by such Person, whether or not assumed by such Person, (vi) obligations of the
type described in clauses (i)-(iv) above for which such Person is obligated
pursuant to a Guaranty, (vii) obligations of such Person to reimburse or
otherwise indemnify issuers of letters of credit or surety bonds (or equivalent
third party instruments) and (viii) the amount of any reserve required to be
established by such Person under GAAP for any judgment against it. The amount
computed



                                      -42-
<PAGE>   22

under clause (viii) shall only be included in Total Funded Debt to the extent,
if any, the amount so computed exceeds $250,000. To the extent outstanding
Hedging Loans do not exceed $15,000,000 (based upon the exchange rate between
U.S. Dollars and each relevant currency at the time each such loan is borrowed
and at the end of each calendar quarter thereafter) such Hedging Loans shall be
excluded from the computation of Total Funded Debt and Debt of Subsidiaries
restricted by Section 7.21.

         "Default" means any event or condition the occurrence of which would,
with the passage of time or the giving of notice, or both, constitute an Event
of Default.

         "Domestic Rate" is defined in Section 1.3(a) hereof.

         "Domestic Rate Loan" means a Loan bearing interest prior to maturity at
the rate specified in Section 1.3(a) hereof.

         "Effective Date" means the date on which the Agent has received signed
counterpart signature pages of this Agreement from each of the signatories (or,
in the case of a Bank, confirmation that such Bank has executed such a
counterpart and dispatched it for delivery to the Agent) and the documents
required by Section 6.1 hereof.

         "ERISA" is defined in Section 5.9 hereof.

         "ERISA Affiliate" means each member o a controlled group of
corporations and each trade or business (whether or not incorporated) that,
together with the Borrower, is treated as a single employer under Section 414 of
the Code, and the regulations promulgated and rulings issued thereunder.

         "Eurodollar Loan" means a Loan bearing interest prior to maturity at
the rate specified in Section 1.3(b) hereof.

         "Eurodollar Margin" is defined in Section 1.3(b) hereof.

         "Eurodollar Reserve Percentage" is defined in Section 1.3(b) hereof.

         "Event of Default" means any of the events or circumstances specified n
Section 8.1 hereof.

         "Federal Funds Rate" means the fluctuating interest rate per annum
described in part (x) of clause (ii) of the definition of Domestic Rate in
Section 1.3(a) hereof.

         "Fixed Charge Coverage Ratio" means, for any period of the Borrower and
its Subsidiaries, the ratio, calculated without duplication, of (i) their
consolidated net income during such period (excluding "extraordinary" and
"unusual or non-recurring" gains and losses) plus (A) income tax expense (or
minus any income tax credit), whether current or deferred, to the extent
deducted from (or added to) income before taxes in determining consolidated net
income for such period, and (B) interest expense (net of interest income)



                                      -43-
<PAGE>   23

deducted from consolidated net income for such period, to (ii) the sum of (w)
interest expense (net of interest income) for such period, (x) dividends paid
or accrued on preferred stock for such period, (y) operating lease expense
(other than under FASB 13 "synthetic leases") for real property for such fiscal
period to the extent it has exceeded $4,000,000 during the four quarter period
ending with such fiscal period and (z) the imputed interest component of
Capitalized Lease Obligations and FASB 13 "synthetic leases" paid or accrued
during such period, all as determined in accordance with GAAP for such fiscal
period, except that, if not dictated by GAAP, the imputed interest component of
Capital Lease Obligations and of payments under "synthetic leases" will be
determined by any reasonable method selected and disclosed to the Banks by
the Borrower and not objected to by the Required Banks.

         "GAAP" means generally accepted accounting principles from time to time
in effect.

         "Guaranty" by any Person shall mean all obligations (other than
endorsements in the ordinary course of business of negotiable instruments for
deposit or collection) of such Person guaranteeing or in effect guaranteeing any
Indebtedness, dividend or other obligation (including, without limitation,
limited or full recourse obligations in connection with sales of receivables or
any other Property) of any other Person (the "primary obligor") in any manner,
whether directly or indirectly, including, without limitation, all obligations
in connection with letters of credit, surety bonds, or similar instruments
issued for the account of such Person or for which such Person is otherwise
liable and all obligations incurred through an agreement, contingent or
otherwise, by such Person: (i) to purchase such Indebtedness or obligation or
any Property or assets constituting security therefor, (ii) to advance or supply
funds (x) for the purchase or payment of such Indebtedness or obligation, (y) to
maintain working capital or other balance sheet condition or otherwise to
advance or make available funds for the purchase or payment of such Indebtedness
or obligation, or (iii) to lease property or to purchase Securities or other
property or services primarily for the purpose of assuring the owner of such
Indebtedness or obligation of the ability of the primary obligor to make payment
of the Indebtedness or obligation, or (iv) otherwise to assure the owner of the
Indebtedness or obligation of the primary obligor against loss in respect
thereof. For the purpose of all computations made under this Agreement, the
amount of a Guaranty in respect of any obligation shall be deemed to be equal to
the maximum aggregate amount of such obligation or, if the Guaranty is limited
to less than the full amount of such obligation, the maximum aggregate potential
liability under the terms of the Guaranty.

         "Hedging Loan" means a loan in one currency incurred by the Borrower or
a Subsidiary to purchase another currency when such purchased currency (or
temporarily the borrowed currency) is then pledged to the lender to secure such
loan.

         "Indebtedness" means, and includes, as to any Person, all obligations
of such Person which are required by GAAP to be shown as liabilities on its
balance sheet.

         "Indenture" means a trust indenture, bond resolution or other similar
instrument pursuant to which Bonds are issued, including any amendments or
supplements thereto.



                                      -44-
<PAGE>   24

         "Interest Period" is defined in Section 1.6 hereof.

         "Issuing Bank" is defined in Section 1.2(d) hereof and shall include
any assignee of an Issuing Bank that assumes the Issuing Bank's obligations and
rights hereunder.

         "L/C Documents" means the Letters of Credit, any draft or other
document presented in connection with a drawing thereunder, the Applications,
the Reimbursement Agreements and this Agreement.

         "L/C Obligations" means the undrawn face amounts of all outstanding
Letters of Credit and all unpaid Reimbursement Obligations.

         "Lending Office" is defined in Section 9.4 hereof.

         "Letter of Credit" is defined in Section 1.2(c) hereof.

         "LIBOR" is defined in Section 1.3(b) hereof.

         "Lien" means any interest in Property securing an obligation owed to,
or a claim by, a Person other than the owner of the Property, whether such
interest is based on the common law, statute or contract, including, but not
limited to, the security interest lien arising from a mortgage, encumbrance,
pledge, conditional sale, security agreement or trust receipt, or a lease,
consignment or bailment for security purposes. The term "Lien" shall also
include reservations, exceptions, encroachments, easements, rights of way,
covenants, conditions, restrictions, leases and other title exceptions and
encumbrances affecting Property. For the purposes of this definition, a Person
shall be deemed to be the owner of any Property which it has acquired or holds
subject to a conditional sale agreement, Capital Lease or other arrangement
pursuant to which title to the Property has been retained by or vested in some
other Person for security purposes, and such retention of title shall constitute
a "Lien."

         "Loan" is defined in Section 1.1 hereof and, as so defined, includes a
Domestic Rate Loan or Eurodollar Loan, each of which is a "type" of Loan
hereunder.

         "MARTA" is defined in the introductory paragraph hereof.

         "MARTA Group" means MARTA, its Subsidiaries, and any other Affiliate of
the Borrower that engages in the business of constructing, maintaining or
operating vehicle emissions test sites or the business of contracting to provide
such services directly or indirectly through subcontractors.

         "Maryland Surety Bonds" means surety bonds issued by the Borrower to
guarantee MARTA's performance under the contract between MARTA and the Maryland
Department of Transportation relating to MARTA's construction and operation of
vehicle inspection facilities in the State of Maryland. For the purpose of all
computations made under this Agreement, the amount of the Maryland Surety Bond
relating to the construction of vehicle inspection facilities in the State of
Maryland shall be deemed to be equal to the amount 



                                      -45-
<PAGE>   25

owing by the State of Maryland to the Borrower under the contract between MARTA
and the Maryland Department of Transportation relating to MARTA's construction
of vehicle inspection facilities in the State of Maryland, and the amount of the
Maryland Surety Bond relating to the operation of vehicle inspection facilities
in the State of Maryland shall be deemed to be equal to the face amount of such
bond.

         "Note" is defined in Section 1.10(a) hereof.

         "Obligations" means all fees payable hereunder, all obligations of the
Borrower to pay principal or interest on Loans and Reimbursement Obligations,
and all other obligations of the Borrower arising under or in relation to any
Credit Document.

         "Operating Lease" means any lease of any real or personal property that
is not a Capital Lease. The imputed principal component of obligations under an
Operating Lease will be determined for purposes of clause (viii) of the
definition of Debt by any reasonable method selected by the Borrower and
disclosed to the Banks that is not objected to by the Required Banks.

         "Participating Bank" is defined in Section 1.2(e) hereof.

         "PBGC" is defined in Section 5.9 hereof.

         "Percentage" is defined in Section 1.1 hereof.

         "Person" means an individual, partnership, corporation, association,
trust, unincorporated organization or any other entity or organization,
including a government or agency or political subdivision thereof.

         "Plan" means at any time an employee pension benefit plan which is
covered by Title IV of ERISA or subject to the minimum funding standards under
Section 412 of the Code and is either (i) maintained by an ERISA Affiliate for
employees of such ERISA Affiliate or (ii) maintained pursuant to a collective
bargaining agreement or any other arrangement under which more than one employer
makes contributions and to which an ERISA Affiliate is then making or accruing
an obligation to make contributions or has within the preceding five plan years
made contributions.

         "Pricing Change Date" means, for any fiscal quarter of the Borrower
ended after the date here f, the latest date by which the Borrower is required
to deliver a Compliance Certificate for such fiscal quarter pursuant to Section
7.6(a). The Eurodollar Margin and the Commitment Fee Rate established on a
Pricing Change Date shall remain in effect until the next Pricing Change Date.
If the Borrower has not delivered a Compliance Certificate by the date such
Compliance Certificate is required to be delivered under Section 7.6(a), until a
Compliance Certificate is delivered before the next Pricing Change Date, the
Eurodollar Margin shall be 1.50% per annum and the Commitment Fee Rate shall be
0.50% per annum. If the Borrower subsequently delivers such a Compliance
Certificate before the next Pricing Change Date, the Eurodollar Margin and
Commitment Fee Rate established by 



                                      -46-
<PAGE>   26

such late delivered Compliance Certificate shall take effect from the date of
delivery until the next Pricing Change Date. In all other circumstances, the
Eurodollar Margin and Commitment Fee Rate established by a Compliance
Certificate shall be in effect from the Pricing Change Date that occurs
immediately after the end of the Borrower's fiscal quarter covered by such
Compliance Certificate until the next Pricing Change Date.

         "Property" means any interest in any kind of property or asset, whethe
real, personal or mixed, or tangible or intangible, whether now owned or
hereafter acquired.

         "Redeemable Preferred Stock" means preferred stock of the Borrower and
its Subsidiaries that the holder can require be redeemed (it being understood
that a right solely to convert preferred stock into common stock is not a
redemption right).

         "Refunding Borrowing" means any Borrowing of Loans that refunds in
whole or in part outstanding Loans at their maturity and does not increase the
aggregate outstanding amount of Loans as further defined in Section 1.5(d)
hereof.

         "Reimbursement Agreement" means each agreement between the Borrower and
Dresdner Bank AG, New York Branch relating to a Bond Letter of Credit identified
under the column "Reimbursement Agreement" on Schedule 1.2(c) hereto, as any
such agreement may be amended or otherwise modified in accordance with the terms
hereof.

         "Reimbursement Obligation" is defined in Section 1.2(d) hereof.

         "Required Banks" means, as of the date of determination thereof, either
Banks holding at least a majority of the Commitments or, if the Commitments have
been terminated in whole, Banks holding at least a majority in aggregate
principal amount of the Loans and L/C Obligations (calculated after giving
effect to each Participating Bank's Percentage participation therein)
outstanding hereunder; provided that the Required Banks must at all times be
comprised of at least four Banks.

         "Requirement of Law" means, as to any Person, the Certificate of
Incorporation and By-Laws or other organizational or governing documents of such
Person, and any law, treaty, rule or regulation or determination of an
arbitrator or a court or other governmental authority, in each case applicable
to or binding upon such Person or any of its Property or to which such Person or
any of its Property is subject.

         "Restricted Investment [Stigma] means, for the Borrower and each of its
Subsidiaries, any investment in any other Person, computed in accordance with
GAAP, made by stock purchase, capital contribution, loan, advance, extension of
credit, acquisition of property, but not the creation or assumption of any
Contingent Obligation in respect of any obligation of such other Person;
provided, however, that investments of the Borrower or Subsidiaries in
Subsidiaries that are consolidated with the Borrower under GAAP (including
investments in a Person that, after giving effect to such investments, is such a
Subsidiary) and investments of Subsidiaries in the Borrower shall not be
Restricted Investments, and provided further that the following investments
shall not be Restricted Investments:


                                      -47-
<PAGE>   27

                  (i) investments by the Borrower or any Subsidiary in
         commercial paper or similar short term obligations (including tax
         exempt securities) maturing in 270 days or less from the date of
         acquisition which, at the time of acquisition by the Borrower or the
         Subsidiary, is accorded one of the two highest ratings (without regard
         to gradations, such as "+" or "-", within a single ratings category)
         available from Standard & Poor's, Moody's Investors Service, Inc. or
         any other nationally recognized credit rating agency of similar
         standing providing similar ratings;

                  (ii) investments by the Borrower or any Subsidiary in direct
         obligations of the United States of America, or any agency thereof (or
         by any other national government or agency thereof if invested in by a
         Subsidiary operating in such country investing revenue earned in the
         currency of such country), maturing in five years or less from the date
         of acquisition thereof;

                  (iii) investments by the Borrower or any Subsidiary in
         certificates of deposit maturing within five years from the date of
         origin and bankers' acceptances maturing within 180 days from the date
         of origin, in each case issued by a Bank hereunder or any bank or trust
         company organized under the laws of the United States or any state
         thereof (or under the laws of the country in which a Subsidiary
         operates, if such Subsidiary is investing revenues earned in the
         currency of such country) having capital, surplus and undivided profits
         aggregating at least $100,000,000 (or its equivalent in another
         currency if a non-United States bank);

                  (iv) investments by the Borrower or any Subsidiary consisting
         of purchases of participation interests from banks described in item
         (iii) of this definition in notes maturing in 270 days or less from the
         date of issuance issued by corporations or other entities whose
         short-term debt, at the time of acquisition of the participation by the
         Borrower or any Subsidiary, is accorded one of the two highest ratings
         available from Standard & Poor's, Moody's Investors Service, Inc. or
         any other nationally recognized credit rating agency of similar
         standing providing similar ratings;

                  (v) loans or advances (not to exceed $2,000,000 in the
         aggregate outstanding) in the usual and ordinary course of business to
         officers, directors and employees for expenses (including moving
         expenses related to a transfer) incidental to carrying on the business
         of the Borrower or any Subsidiary; and

                  (vi) receivables arising from the sale of goods and services
         in the ordinary course of business of the Borrower and its
         Subsidiaries.

         "Revolver Issuer" is defined in Section 1.2(a) hereof.

         "Revolver Letters of Credit" is defined in Section 1.2(a) hereof.

         "Revolving Obligations" means, for the Borrower at any time, the sum of
the principal amount of the Loans and L/C Obligations under Revolver Letters of
Credit then outstanding.



                                      -48-
<PAGE>   28

         "SEC" means the Securities and Exchange Commission.

         "Security" has the same meaning as in Section 2(l) of the Securities
Act of 1933, as amended.

         "Set-Off" is defined in Section 11.7 hereof.

         "Subordinated Debt" means any Debt of the Borrower that has been
subordinated to all Obligations on terms and conditions (including covenants and
acceleration or mandatory prepayment provisions) acceptable to the Required
Banks.

         "Subordinated Debt Amount" means, at any time, the aggregate principal
amount of outstanding Subordinated Debt up to an amount equal to 25% of
Consolidated Net Worth.

         "Subsidiary" means any corporation or other entity of which more than
fifty percent (50%) of the outstanding stock or comparable equity interests
having ordinary voting power for the election of the Board of Directors of such
corporation or similar governing body in the case of a non-corporation
(irrespective of whether or not, at the time, stock or other equity interests of
any other class or classes of such corporation or other entity shall have or
might have voting power by reason of the happening of any contingency) is at the
time directly or indirectly owned by the Borrower or by one or more of its
Subsidiaries, or by the Borrower and one or more of its Subsidiaries.

         "Substitute Bank" is defined in Section 9.3(d) hereof.

         "Termination Date" means December 18, 1999.

         "Total Cash Flow" means, for any fiscal quarter of the Borrower and its
Subsidiaries, their consolidated net income minus (A) "extraordinary" and
"unusual or non-recurring" gains, plus (B) "extraordinary" and "unusual or
non-recurring" losses, plus (C) depreciation expense, plus (D) non-cash
amortization expense, all determined in accordance with GAAP for the four fiscal
quarter period of the Borrower and its Subsidiaries ending with such fiscal
quarter. It is understood that gains or losses properly classified under GAAP as
resulting from discontinued operations are not "extraordinary" or "unusual or
non-recurring".

         "Total Funded Debt" means, at any time, all then outstanding Debt of t
e Borrower and its Subsidiaries determined, without duplication, on a
consolidated basis.

         "Total Funded Debt to Cash Flow Ratio" means, at any time, the ratio of
Total Funded Debt to Total Cash Flow as of the last day of the then most
recently completed fiscal quarter of the Borrower.

         "Trustee" means the trustee, or equivalent fiduciary, appointed under
any Indenture.



                                      -49-
<PAGE>   29

         "Unfunded Vested Liabilities" means, with respect to any Plan at any
time, the amount (if any) by which (i) the present value of all vested
nonforfeitable accrued benefits under such Plan exceeds (ii) the fair market
value of all Plan assets allocable to such benefits, all determined in
accordance with the actuarial assumptions used by the actuary for each Plan as
of the then most recent actuarial valuation date for such Plan, but only to the
extent that such excess represents a potential liability of the Borrower or any
ERISA Affiliate to the PBGC or the Plan under Title IV of ERISA.

         "U.S. Tax Returns" is defined in Section 5.7 hereof.

         "Voting Stock" of any Person means capital stock of any class or
classes or other equity interests (however designated) having ordinary voting
power for the election of directors or equivalent governing body of such Person,
other than stock or other equity interests having such power only by reason of
the happening of a contingency.

         "Welfare Plan" means a "welfare plan", as defined in Section 3(1) of
ERISA.

         "Wholly-Owned" when used in connection with any Subsidiary of the
Borrower means a Subsidiary of which all of the issued and outstanding shares of
stock or other equity interests (other than directors' qualifying shares as
required by law) shall be owned by the Borrower and/or one or more of its
Subsidiaries.

         Section 4.2. Interpretation. The foregoing definitions shall be equally
applicable to both the singular and plural forms of the terms defined. All
references to times of day shall be references to Chicago, Illinois time unless
otherwise specifically provided. Where the character or amount of any asset or
liability or item of income or expense is required to be determined or any
consolidation or other accounting computation is required to be made for the
purposes of this Agreement, it shall be done in accordance with GAAP applied in
a manner consistent with the Borrower's December 31, 1995 financial statements
referred to in Section 5.4 hereof, except where such principles are inconsistent
with specific provisions of this Agreement; provided that, if (within six months
after the application of such a change in GAAP) the Borrower notifies the Agent
that the Borrower wishes to amend any provision hereof to eliminate the effect
of any change after the date hereof in GAAP (including its generally accepted
application or interpretation) on the operation of a provision of this Agreement
(or if the Agent notifies the Borrower within such six month period that the
Required Banks wish to amend any provision for such purpose), then such
provision shall be interpreted and the Borrower's compliance with and
performance under such provision shall be determined on the basis of GAAP in
effect immediately before the relevant change in GAAP became effective, until
either such notice is withdrawn or such provision is amended in a manner
satisfactory to the Borrower and the Required Banks.

SECTION 5. REPRESENTATIONS AND WARRANTIES.

         The Borrower represents and warrants to each Bank as follows:



                                      -50-
<PAGE>   30

         Section 5.1. Corporate Organization and Authority. The Borrower is duly
organized and existing in good standing under the laws of the State of Delaware;
has all necessary corporate power to carry on its present business; and is duly
licensed or qualified and in good standing in each jurisdiction in which the
nature of the business transacted by it or the nature of the Property owned or
leased by it makes such licensing or qualification necessary and in which the
failure to be so licensed or qualified would materially and adversely affect its
business, properties or operations.

         Section 5.2. Subsidiaries. As of the date hereof, the only Subsidiaries
of the Borrower are designated in Schedule 5.2 hereto; each Subsidiary is duly
organized and existing in good standing under the laws of the jurisdiction in
which it was incorporated, has all necessary corporate power to carry on its
present business, and is duly licensed or qualified and in good standing in each
jurisdiction in which the nature of the business transacted by it or the nature
of the Property owned or leased by it makes such licensing or qualification
necessary and in which the failure to be so licensed or qualified would have a
material adverse effect on the financial condition, or the Property, business or
operations, of the Borrower and Subsidiaries taken as a whole. Schedule 5.2
hereto, as it may be updated from time to time pursuant to Section 7.6(a)
hereof, correctly sets forth, as to each Subsidiary, whether or not it is a
consolidated Subsidiary, the jurisdiction of its incorporation, the percentage
of issued and outstanding shares of each class of its capital stock owned by the
Borrower and its Subsidiaries and, if such percentage is not 100% (excluding
directors' qualifying shares as required by law), a description of each class of
its authorized capital stock and the number of shares of each class issued and
outstanding. All of the issued and outstanding shares of capital stock of each
Subsidiary are validly issued and outstanding and fully paid and nonassessable
and all such shares indicated in Schedule 5.2 as owned by the Borrower or a
Subsidiary are owned, beneficially and of record, by the Borrower or such
Subsidiary, free of any Lien.

         Section 5.3. Corporate Authority and Validity of Obligations. The
Borrower has full right and authority to enter into the Credit Documents, to
make the borrowings herein provided for, to issue its Notes in evidence thereof,
to apply for the issuance of the Letters of Credit and to perform all of its
obligations under the Credit Documents; each Credit Document delivered by the
Borrower has been duly authorized, executed and delivered by the Borrower and
constitutes valid and binding obligations of the Borrower enforceable in
accordance with its terms; and no Credit Document, nor the performance or
observance by the Borrower or any Subsidiary of any of the matters or things
therein provided for, contravenes any provision of law or any charter or by-law
provision of the Borrower or any Subsidiary or (individually or in the
aggregate) any material covenant, indenture or agreement of or affecting the
Borrower or any Subsidiary or a substantial portion of their respective
Properties or results in or requires the creation or imposition of any Lien on
any of the Borrower's or any Subsidiary's Properties or revenues.

         Section 5.4. Financial Statements. All public financial statements
showing historical performance of the Borrower and the Subsidiaries heretofore
delivered to the Banks have been prepared in accordance with GAAP applied on a
basis consistent, except as otherwise noted therein, with that of the previous
fiscal year, and fairly present on a consolidated basis



                                      -51-
<PAGE>   31

the financial position of the Borrower and the Subsidiaries as of the dates
thereof, and the results of operations for the periods covered thereby. The
Borrower and its Subsidiaries have no material contingent liabilities other than
those disclosed in such financial statements referred to in this Section 5.4 or
in comments or footnotes thereto or in any supplemental report thereto
heretofore furnished to the Banks.

         Section 5.5. No Material Adverse Change. There has been no material
adverse change in the financial condition or business prospects of the Borrower
and its Subsidiaries on a consolidated basis since June 30, 1996 except to the
extent of the effects of the disposition of the MARTA Group and the notice of
the termination of MARTA's contracts with the State of Ohio as disclosed to the
Banks.

         Section 5.6. No Litigation. There is no litigation or governmental
proceeding pending, or to the knowledge of the Borrower threatened, against the
Borrower or any Subsidiary that has any reasonable possibility of success which,
if adversely determined, would (individually or in the aggregate) materially
adversely affect the financial condition, operations, business, or properties of
the Borrower and its Subsidiaries on a consolidated basis.

         Section 5.7. Taxes. Except as described on Schedule 5.7 hereto, the
United States Federal income tax returns of the Borrower and its Subsidiaries
("U.S. Tax Returns") for the fiscal year ended December 31, 1980, and for all
fiscal years ended prior to said date, have been examined by the Internal
Revenue Service ("IRS") and have been approved as filed, or any additional
assessments in connection with any of such years have been paid. Except as
described on Schedule 5.7 hereto, the Borrower has filed U.S. Tax Returns for
each fiscal year through December 31, 1995, and no audits of the U.S. Tax
Returns for any fiscal year ended after December 31, 1980 are pending, nor to
the knowledge of either Borrower is any objection or controversy threatened.

         Section 5.8. Approvals. No authorization, consent, license, exemption
or filing or registration with any court or governmental department, agency or
instrumentality, or any approval or consent of the stockholders of the Borrower
or from any other Person, is necessary to the valid execution, delivery or
performance by the Borrower of any Credit Document.

         Section 5.9. ERISA. The Borrower and each ERISA Affiliate has fulfilled
its obligations under the minimum funding standards of and is in compliance in
all material respects with the Employee Retirement Income Security Act of 1974,
as amended ("ERISA") and with the Code to the extent applicable to it and has
not incurred any liability to the Pension Benefit Guaranty Corporation ("PBGC")
or a Plan under Title IV of ERISA other than a liability to the PBGC for
premiums under Section 4007 of ERISA. Neither the Borrower nor any Subsidiary
has any material contingent liability with respect to any post-retirement
benefits under a Welfare Plan, other than liability for continuation coverage
described in Part 6 of Title I of ERISA, except as disclosed in the consolidated
financial statements of the Borrower for the fiscal year ended December 31,
1995.



                                      -52-
<PAGE>   32

         Section 5.10. Not an Investment Company. The Borrower is not an
"investment company" as defined in the Investment Company Act of 1940, as
amended.

         Section 5.11. Margin Stock. Neither the Borrower nor any Subsidiary is
engaged principally, or as one of its primary activities, in the business of
extending credit for the purpose of purchasing or carrying margin stock ("margin
stock" to have the same meaning herein as in Regulation U of the Board of
Governors of the Federal Reserve System). Neither the Borrower nor any
Subsidiary will use the proceeds of any Loan in a manner that violates any
provision of Regulations G, U, or X of the Board of Governors of the Federal
Reserve System.

         Section 5.12. Compliance with Environmental Laws. (a) To the best of
the Borrower's knowledge, the business and operations of the Borrower and the
Subsidiaries comply in all respects with all applicable federal, state,
regional, county and local laws, statutes, rules, regulations and ordinances
relating to public health, safety or the environment, including, without
limitation, relating to releases, discharges, emissions or disposals to air,
water, land or groundwater, to the withdrawal or use of groundwater, to the use,
handling or disposal of polychlorinated biphenyls (PCBs), asbestos or urea
formeldahyde, to the treatment, storage, disposal or management of hazardous
substances (including, without limitation, petroleum, its derivatives or
by-products, or other hydrocarbons), to exposure to toxic, hazardous, or other
controlled, prohibited or regulated substances, to the transportation, storage,
disposal, management or release of gaseous or liquid substances, and any
regulation, order, injunction, judgment, declaration, notice or demand issued
thereunder, except where the failure to so comply would not (individually or in
the aggregate) have a material adverse effect on the Property, business or
operations of the Borrower and the Subsidiaries taken as a whole.

         (b) Except as set forth on Schedule 5.12 hereto (as updated pursuant to
Section 7.14(b) and with this representation remaining true so long as all such
updated information is delivered by the time required by Section 7.14(b)),
neither the Borrower nor any Subsidiary has given, nor is it required to give,
nor has it received, any notice, letter, citation, order, warning, complaint,
inquiry, claim or demand to or from any governmental entity or in connection
with any court proceeding that: (i) the Borrower or any Subsidiary has violated,
or is about to violate, any federal, state, regional, county or local
environmental, health or safety statute, law, rule, regulation, ordinance,
judgment or order; (ii) there has been a release, or there is a threat of
release, of hazardous substances (including, without limitation, petroleum, its
by-products or derivatives, or other hydrocarbons) from the Borrower's or any
Subsidiary's property, facilities, equipment or vehicles; (iii) the Borrower or
any Subsidiary may be or is liable, in whole or in part, for the costs of
cleaning up, remediating or responding to a release of hazardous substances
(including, without limitation, petroleum, its by-products or derivatives, or
other hydrocarbons); or (iv) any of the Borrower's or any Subsidiary's property
or assets are subject to a Lien in favor of any governmental entity for any
liability, costs or damages, under any federal, state or local environmental
law, rule or regulation arising from, or costs incurred by such governmental
entity in response to, a release of a hazardous substance



                                      -53-
<PAGE>   33

(including, without limitation, petroleum, its by-products or derivatives, or
other hydrocarbons).

         Section 5.13. Ownership of Property; Liens. The Borrower and its
Subsidiaries have good record and marketable title in fee simple to or valid
leasehold interests in all their respective real property, and good title to or
valid leasehold interests in all their respective other property, and none of
such property is subject to any Lien, except as permitted in Section 7.9.

         Section 5.14. No Burdensome Restrictions. Neither the Borrower nor any
Subsidiary is party to or subject to any law, regulation, rule or order, or any
Contractual Obligation that (individually or in the aggregate) materially
adversely affects, or insofar as the Borrower may reasonably foresee may so
affect, the business, operations, Property or financial condition of the
Borrower and its Subsidiaries taken as a whole.

         Section 5.15. Long Term Debt. As of the date hereof, all Debt of the
Borrower and its Subsidiaries with a remaining scheduled maturity of more than
one (1) year is listed on Schedule 5.15 hereto.

SECTION 6. CONDITIONS PRECEDENT.

         The obligation of each Bank to make any Loan hereunder, or of the
Issuing Bank to issue, extend the expiration date of or increase the amount of
any Letter of Credit, shall be subject to the following conditions precedent:

         Section 6.1. Initial Credit Event. Prior to the first Credit Event
hereunder:

                  (a) The Agent shall have received for each Bank the favorable
         written opinion of McDara P. Folan, III, Vice President, Secretary and
         General Counsel of the Borrower, in substantially the form attached
         hereto as Exhibit C, and otherwise in form and substance satisfactory
         to the Banks;

                  (b) The Agent shall have received for each Bank copies
         (executed or certified as may be appropriate) of all legal documents or
         proceedings taken in connection with the Borrower's execution and
         delivery of this Agreement and the Notes to the extent the Agent or the
         Required Banks may reasonably request;

                  (c) The Agent shall have received for the Banks a certificate
         from the Borrower's Secretary or Assistant Secretary confirming that
         the Borrower's Certificate of Incorporation and bylaws have not been
         amended since December 18, 1995 and that true and correct copies of
         such Certificate of Incorporation and bylaws, as amended and currently
         in effect, were delivered pursuant to Section 6.1(c) of the Original
         Credit Agreement;

                  (d) The Agent shall have received from the Borrower a list of
         its Authorized Representatives and certified resolutions of its Board
         of Directors authorizing the



                                      -54-
<PAGE>   34

         execution and delivery of the Credit Documents and the consummation of
         the transactions contemplated thereby, together with a certification of
         the incumbency and specimen signatures of each of the officers of the
         Borrower executing Credit Documents on its behalf; and

                  (e) MARTA shall have repaid all Obligations it owes under the
         Original Credit Agreement, except that fees accrued under Section 2 of
         the Original Credit Agreement that are not due on the Effective Date
         shall be payable by the Borrower hereunder on the same date(s) such
         fees would have been payable under the Original Credit Agreement if it
         had remained in effect.

         Section 6.2. All Credit Events. As of the time of each Credit Event
hereunder (including the initial Credit Event):

                  (a) In the case of a Borrowing, the Agent shall have received
         for the account of each Bank its Notes and the notice required by
         Section 1.5 hereof and, in the case of the issuance of any Revolver
         Letter of Credit, the Issuing Bank shall have received a duly completed
         Application for the Letter of Credit and, in the case of an extension
         or increase in the amount of a Letter of Credit, a written request
         therefor, in a form acceptable to the Issuing Bank;

                  (b) Each of the representations and warranties of the Borrower
         set forth in Section 5 hereof (except, in the case of a Refunding
         Borrowing only, for the representation and warranty appearing in
         Section 5.5 hereof) shall be and remain true and correct in all
         material respects as of said time, except to the extent that any such
         representation or warranty relates solely to an earlier date;

                  (c) The Borrower shall be in full compliance with all of the
         terms and conditions hereof, and no Default or Event of Default shall
         have occurred and be continuing or would occur as a result of such
         Credit Event;

                  (d) The aggregate outstanding principal amount of Revolving
         Obligations of the Borrower, after giving effect to the proposed Credit
         Event, shall not exceed the Commitments then in effect;

                  (e) In the case of the issuance of, or the increase in the
         amount of, a Revolver Letter of Credit the aggregate undrawn face
         amount of all outstanding Revolver Letters of Credit after giving
         effect to such proposed Credit Event shall not exceed $20,000,000; and

                  (f) Such Credit Event shall not violate any order, judgment or
         decree of any court or other authority or any provision of law or
         regulation applicable to any Bank (including, without limitation,
         Regulation U of the Board of Governors of the Federal Reserve System)
         as then in effect.



                                      -55-
<PAGE>   35

         Each request for a Borrowing hereunder shall be deemed to be a
representation and warranty by the Borrower on the date of such Borrowing as to
the facts specified in paragraphs (b), (c), (d) and (e) of this Section 6.2.

SECTION 7. COVENANTS.

         The Borrower covenants and agrees that, so long as any Note, any Letter
of Credit or any Reimbursement Obligation is outstanding hereunder or any credit
is available to or in use by the Borrower hereunder, except to the extent
compliance in any case is waived in writing by the Required Banks:

         Section 7.1. Corporate Existence. The Borrower shall, and shall cause
each of its Subsidiaries to, preserve and maintain its corporate existence,
subject to the provisions of Section 7.13 hereof.

         Section 7.2. Maintenance. The Borrower will, and will cause each
Subsidiary to, maintain, preserve and keep its plants, properties and equipment
deemed by it necessary to the proper conduct of its business in reasonably good
repair, working order and condition and will from time to time make all
reasonably necessary repairs, renewals, replacements, additions and betterments
thereto so that at all times such plants, properties and equipment shall be
reasonably preserved and maintained; provided, however, that nothing in this
Section 7.2 shall prevent the Borrower or a Subsidiary from discontinuing the
operation or maintenance of any such properties if such discontinuance is, in
the judgment of the Borrower, desirable in the conduct of its business or the
business of the Subsidiary and not disadvantageous to the Banks or the holders
of the Notes.

         Section 7.3. Taxes. The Borrower will duly pay and discharge, and will
cause each Subsidiary to pay and discharge, all taxes, rates, assessments, fees
and governmental charges upon or against the Borrower or such Subsidiary or
against their respective Properties, in each case before the same becomes
delinquent and before penalties accrue thereon, unless and to the extent that
the same is being contested in good faith and by appropriate proceedings and
reserves in conformity with GAAP have been provided therefor on the books of the
Borrower or such Subsidiary, as the case may be.

         Section 7.4. ERISA. The Borrower will, and will cause each ERISA
Affiliate to, promptly pay and discharge all obligations and liabilities arising
under ERISA of a character which if unpaid or unperformed might result in the
imposition of a Lien against any of its properties or assets and will promptly
notify the Agent of (i) the occurrence of any reportable event (as defined in
ERISA) with respect to a Plan, other than any such event of which the PBGC has
waived notice by regulation, (ii) receipt of any notice from PBGC of its
intention to seek termination of any Plan or appointment of a trustee therefor,
(iii) its or any Subsidiary's intention to terminate or withdraw from any Plan,
and (iv) the occurrence of any event with respect to any Plan which could result
in the incurrence by the Borrower or any Subsidiary of any material liability,
fine or penalty, or any material increase in the contingent liability of the
Borrower or any Subsidiary with respect to any post-retirement Welfare Plan
benefit; provided that, for items described in clause (i)-(iii) above that
affect 



                                      -56-
<PAGE>   36

multiemployer plans (i.e. those described in clause (ii) of the definition of
Plan) that are immaterial to the Borrower and its ERISA Affiliates, the Borrower
need only notify the Agent of such events on an annual basis at the time it
delivers the financial statements required to be delivered pursuant to Section
7.6(a)(ii) hereof.

         Section 7.5. Insurance. The Borrower will insure, and keep insured, and
will cause each Subsidiary to insure, and keep insured, in good and responsible
insurance companies, all insurable Property owned by it which is of a character
usually insured by companies similarly situated and operating like Property; and
to the extent usually insured (subject to self-insured retentions) by companies
similarly situated and conducting similar businesses the Borrower will also
insure, and will cause each of its Subsidiaries to insure, employers' and public
and product liability risks in good and responsible insurance companies. The
Borrower will upon request of the Agent furnish a summary setting forth the
nature and extent of the insurance maintained pursuant to this Section 7.5.

         Section 7.6. Financial Reports and Other Information. (a) The Borrower
will maintain a system of accounting in accordance with GAAP and will furnish to
the Banks and their respective duly authorized representatives such information
respecting the business and financial condition of the Borrower and Subsidiaries
as the Required Banks or the Agent may reasonably request; and without any
request the Borrower will furnish to each Bank:

                  (i) within 60 days after the end of each of the Borrower's
         first three quarterly fiscal periods, a copy of the Borrower's Form
         10-Q Report filed with the SEC;

                  (ii) within 100 days after the end of each fiscal year of the
         Borrower, a copy of the Borrower's Form 10-K Report filed with the SEC,
         including a copy of the annual report of the Borrower and its
         Subsidiaries for such year with accompanying consolidated financial
         statements, prepared by the Borrower and, in the case of the
         consolidated financial statements of the Borrower and its Subsidiaries,
         certified by Coopers & Lybrand or other independent public accountants
         of recognized standing selected by the Borrower and satisfactory to the
         Required Banks stating that they audited the consolidated financial
         statements in accordance with generally accepted auditing standards and
         in their opinion such statements present fairly, in all material
         respects, the consolidated financial position of the Borrower and its
         Subsidiaries as of the end of the fiscal year and the consolidated
         results of operations for the fiscal year then ended;

                  (iii) promptly after the sending or filing thereof, copies of
         all proxy statements, financial statements and reports that the
         Borrower sends to its shareholders, and copies of all other regular,
         periodic and special reports and all registration statements the
         Borrower files with the SEC or any successor thereto, or with any
         national securities exchange; and

                  (iv) an updated Schedule 5.2 along with the financial
         statements delivered under Subsection (i) or (ii) above, as applicable,
         for any calendar quarter during 



                                      -57-
<PAGE>   37

         which there is a change in any of the facts specified in Schedule 5.2,
         as then most recently updated. 

Each of the financial statements furnished to the Banks pursuant to subsections
(i) and (ii) of this Section 7.6(a) shall be accompanied by a Compliance
Certificate signed by the chief financial officer or Controller or Treasurer of
the Borrower (it being understood that in preparing such certificate the
officer's determination of compliance will be based upon periodic, not daily,
financial reporting, but that this does not in any way limit or otherwise affect
the requirements of any part of this Section 7 or of any other provision of this
Agreement that the Borrower at all times be in compliance with the terms and
conditions of this Agreement). In the event the Borrower is no longer required
to file Form 10-Q and 10-K Reports with the SEC, it will nevertheless furnish to
the Banks at the time hereinabove set forth all the financial and other
information that would have comprised such filings.

         (b) The Borrower will permit each Bank (or such Persons as any Bank may
designate) to visit and inspect, under the Borrower's guidance, any of the
properties of the Borrower or any Subsidiary, to examine all their books of
account, records, reports and other papers, to make copies and extracts
therefrom, and to discuss their respective affairs, finances and accounts with
their respective officers, employees and independent public accountants (and by
this provision the Borrower authorizes such accountants to discuss with the
Banks the finances and affairs of the Borrower and Subsidiaries) all at such
reasonable times and as often as may be reasonably requested.

         (c) The Borrower will promptly give notice to the Agent and each Bank
(and in any event within two Business Days after the Borrower has knowledge
thereof):

                  (i) of the occurrence of any Default or Event of Default;

                  (ii) of any default or event of default under any material
         Contractual Obligation of the Borrower or any Subsidiary;

                  (iii) of a material adverse change in the business,
         operations, property or financial or other condition of the Borrower
         and its Subsidiaries taken as a whole.

         Section 7.7. Change of Control. If a Change of Control shall occur, the
Borrower will, within 1 Business Day after either becomes aware of the
occurrence thereof, give the Agent notice thereof and describe in reasonable
detail the facts and circumstances giving rise thereto.

         Section 7.8. Conduct of Business. The Borrower and its Subsidiaries
will not engage in any business if, as a result, the general nature of the
business which would then be engaged in by the Borrower and its Subsidiaries
would be substantially changed from the general nature of the business engaged
in by the Borrower and its Subsidiaries on the date of this Agreement.



                                      -58-
<PAGE>   38

         Section 7.9. Liens. The Borrower will not, nor will it permit any
Subsidiary to, create, incur, or permit to exist or to be incurred any Lien of
any kind on any Property owned by the Borrower or any Subsidiary; provided,
however, that this Section 7.9 shall not apply to nor operate to prevent:

                  (a) Liens in connection with worker's compensation,
         unemployment insurance, old age benefits (in any case not including
         Liens under ERISA), social security obligations, taxes, assessments,
         statutory obligations or other similar charges, good faith deposits,
         pledges or Liens in connection with bids, tenders, contracts or leases
         to which the Borrower or any Subsidiary is a party (other than
         contracts for borrowed money), or other deposits required to be made in
         the ordinary course of business; provided that in each case the
         obligation secured is not overdue or, if overdue, is being contested in
         good faith by appropriate proceedings and for which reserves in
         conformity with GAAP have been provided on the books of the Borrower or
         such Subsidiary, as the case may be;

                  (b) mechanics', workmen's, materialmen's, landlords',
         carriers' or other similar Liens arising in the ordinary course of
         business (or deposits to obtain the release of such Liens) with respect
         to obligations which are not due or, if due, are being contested in
         good faith by appropriate proceedings and for which reserves in
         conformity with GAAP have been provided on the books of the Borrower or
         such Subsidiary, as the case may be;

                  (c) Liens arising out of judgments or awards against the
         Borrower or any Subsidiary, or in connection with surety or appeal
         bonds in connection with bonding such judgments or awards, the time for
         appeal from which or petition for rehearing of which shall not have
         expired or with respect to which the Borrower or such Subsidiary shall
         be prosecuting an appeal or proceeding for review, and with respect to
         which it shall have obtained a stay of execution pending such appeal or
         proceeding for review; provided that the aggregate amount of
         liabilities (including interest and penalties, if any) of the Borrower
         and the Subsidiaries secured by such Liens shall not exceed $2,000,000
         at any one time outstanding;

                  (d) Liens upon any Property acquired by the Borrower or any
         Subsidiary after the date hereof (A) to secure the payment of all or
         any part of the purchase price of such Property upon the acquisition
         thereof by the Borrower or such Subsidiary, or (B) to secure any
         indebtedness issued, assumed or guaranteed by the Borrower or any
         Subsidiary prior to, at the time of, or within 90 days after the
         acquisition of such Property, which indebtedness is issued, assumed or
         guaranteed for the purpose of financing all or any part of the purchase
         price of such Property, provided that in the case of any such
         acquisition the Lien shall not apply to any Property other than the
         Property so acquired or purchased;

                  (e) Liens of or upon any Property existing at the time of
         acquisition thereof by the Borrower or any Subsidiary and not created
         in contemplation of such acquisition;



                                      -59-
<PAGE>   39

                  (f) Liens of or upon any Property of a corporation existing at
         the time such corporation is merged with or into or consolidated with
         the Borrower or any Subsidiary or existing at the time of a sale or
         transfer of the properties of a corporation as an entirety or
         substantially as an entirety to the Borrower or any Subsidiary and not
         created in contemplation of such transaction;

                  (g) Liens to secure Debt of any Subsidiary to the Borrower or
         to a Subsidiary so long as the Debt so secured is not related to any
         Indebtedness (other than Indebtedness hereunder) of the secured
         Subsidiary or the Borrower to any Person;

                  (h) Liens for taxes or assessments or other government charges
         or levies not yet due or delinquent, or which can thereafter be paid
         without penalty, or which are being contested in good faith by
         appropriate proceedings and for which reserves in conformity with GAAP
         have been provided on the books of the Borrower or such Subsidiary, as
         the case may be;

                  (i) Options granted to others to purchase real property or
         other assets of the Borrower or any Subsidiary in compliance with
         Section 7.13;

                  (j) Minor survey exceptions or minor encumbrances, easements
         or reservations, or rights of others for rights-of-way, utilities and
         other similar purposes, or zoning or other restrictions as to the use
         of real properties which are necessary for the conduct of the
         activities of the Borrower and Subsidiaries or which customarily exist
         on properties of corporations engaged in similar activities and
         similarly situated and which do not in any event materially impair
         their use in the operation of the business of the Borrower and
         Subsidiaries;

                  (k) Liens, existing as of the date hereof, securing
         Indebtedness of the Borrower or any Subsidiary outstanding on the date
         hereof and listed on Schedule 7.9 to this Agreement;

                  (l) Liens resulting from leases of real or personal property,
         including without limitation Capital Leases, where the Borrower or
         Subsidiary is the lessee and which do not violate the limitations of
         any other provision hereof;

                  (m) any extension, renewal or replacement (or successive
         extensions, renewals or replacements) in whole or in part of any Lien
         referred to in the foregoing paragraphs (a) through (l), inclusive,
         provided, however, that the principal amount of Indebtedness secured
         thereby shall not exceed the principal amount of Indebtedness so
         secured at the time of such extension, renewal or replacement, and that
         such extension, renewal or replacement shall be limited to the Property
         which was subject to the Lien so extended, renewed or replaced;

                  (n) Liens on funds derived from a Hedging Loan (before or
         after the exchange of the borrowed funds into a different currency)
         securing such Hedging Loan; or



                                      -60-
<PAGE>   40

                  (o) Liens not otherwise permitted under this Section 7.9
         securing obligations in an aggregate principal amount not exceeding
         $1,000,000.

         Section 7.10. Compliance with Laws. Without limiting any of the other
covenants of the Borrower in this Section 7, the Borrower will, and will cause
each of its Subsidiaries to, conduct its business, and otherwise be, in
compliance with all applicable laws, regulations, ordinances and orders of any
governmental or judicial authorities; provided, however, that neither the
Borrower nor any Subsidiary shall be required to comply with any such law,
regulation, ordinance or order if (x) it shall be contesting such law,
regulation, ordinance or order in good faith by appropriate proceedings and
reserves in conformity with GAAP have been provided therefor on the books of the
Borrower or such Subsidiary, as the case may be, or (y) the failure to comply
therewith could not, in the aggregate, have a material adverse effect on the
business, operations, property or financial or other condition of the Borrower
and its Subsidiaries on a consolidated basis.

         Section 7.11. Regulation U. The proceeds of each Loan shall be used for
general corporate purposes of the Borrower. The Borrower shall not use any part
of the proceeds of any of the Loans directly or indirectly to purchase or carry
any margin stock (as defined in Section 5.11 hereof) or to extend credit to
others for the purpose of purchasing or carrying any such margin stock except in
compliance with Regulations G, U and X of the Board of Governors of the Federal
Reserve System.

         Section 7.12. Notice of Litigation. The Borrower shall promptly give
notice to the Agent of any litigation or governmental proceeding of the type
described in Section 5.6 hereof.

         Section 7.13. Mergers, Consolidations and Sales of Assets. (a) The
Borrower will not, and will not permit any of its Subsidiaries to, (i)
consolidate with or be a party to a merger with any other Person or (ii) during
any fiscal year, sell, lease or otherwise dispose of all or a "substantial part"
of the consolidated assets of the Borrower and its Subsidiaries; provided,
however, that:

                  (1) any Subsidiary may merge or consolidate with or into or
         sell, lease or otherwise convey all or a substantial part of its assets
         to the Borrower or any other Subsidiary for which the Borrower holds at
         least the same percentage equity ownership; provided that in any such
         merger or consolidation involving the Borrower, the Borrower or Allen
         Telecom Group, Inc. shall be the surviving or continuing corporation
         and shall continue to own all of the assets the Borrower owned
         immediately before such transaction (other than the capital stock of
         Allen Telecom Group, Inc. if it is the surviving or continuing
         corporation); and

                  (2) the Borrower may consolidate or merge with any other
         Person if the Borrower is the surviving or continuing corporation and
         at the time of such consolidation or merger, and after giving effect
         thereto, no Default or Event of Default shall have occurred and be
         continuing. 



                                      -61-
<PAGE>   41

As used in this Section 7.13(a) a sale, lease, transfer or disposition of assets
shall be deemed to be of a "substantial part" of the assets of the Borrower and
its Subsidiaries if the book value of such assets, when added to the book value
of all other assets sold, leased, transferred or disposed of by the Borrower and
such Subsidiaries (other than in the ordinary course of business) during the
same fiscal year, exceeds 5% of the consolidated assets of the Borrower and its
Subsidiaries determined as of the end of the immediately preceding fiscal year.

         (b) The Borrower will not permit any material Subsidiary to issue or
sell any shares of stock of any class (including as "stock" for the purpose of
this subsection any warrants, rights or options to purchase or otherwise acquire
stock or other Securities exchangeable for or convertible into stock) of such
Subsidiary to any Person other than the Borrower or a Wholly-Owned Subsidiary,
except for the purpose of qualifying directors, or except in satisfaction of the
validly pre-existing preemptive rights of minority shareholders in connection
with the simultaneous issuance of stock to the Borrower and/or a Subsidiary
whereby the Borrower and/or such Subsidiary maintain their same proportionate
interest in such Subsidiary.

         (c) The Borrower will not sell, transfer or otherwise dispose of any
shares of stock in any material Subsidiary (except to qualify directors) or any
Indebtedness of any material Subsidiary, and will not permit any Subsidiary to
sell, transfer or otherwise dispose of (except to the Borrower or a Wholly-Owned
Subsidiary) any shares of stock or any Indebtedness of any material Subsidiary,
where "material Subsidiary" for purposes of Section 7.13(b) and (c) means any
Subsidiary constituting or providing 5% or more of the consolidated assets or
revenues of the Borrower and its Subsidiaries.

         Section 7.14. Use of Property and Facilities. (a) The Borrower will,
and will cause each Subsidiary to, comply in all material respects with the
requirements of all federal, state and local environmental and health and safety
laws, rules, regulations and orders applicable to or pertaining to the
Properties or business operations of the Borrower or any Subsidiary.

         (b) The Borrower shall provide the Banks with copies of any material
notice or other instrument of the type described in Section 5.12(b) hereof
within five (5) Business Days after receiving such notice or instrument and of
any non-material notice or instrument at least annually along with the financial
statements required to be delivered pursuant to Section 7.6(a)(ii).

         Section 7.15. Fixed Charge Coverage Ratio. The Borrower will at the end
of each fiscal quarter maintain a Fixed Charge Coverage Ratio, calculated for
the four quarter period ending with such fiscal quarter, of not less than 2.00
to 1.00.

         Section 7.16. Consolidated Tangible Net Worth. The Borrower will at all
times maintain Consolidated Tangible Net Worth in an amount not less than
$80,000,000.

         Section 7.17. Adjusted Consolidated Net Worth. The Borrower will at all
times maintain an Adjusted Consolidated Net Worth of not less than $160,000,000
plus 75% of the cumulative amount of consolidated net income of the Borrower and
its Subsidiaries for each 



                                      -62-
<PAGE>   42

fiscal quarter of the Borrower commencing after September 30, 1995 through the
most recently completed fiscal quarter (without deduction for any consolidated
net loss during any such fiscal quarter), plus 75% of the proceeds from any
capital stock of the Borrower issued after September 30, 1995, minus redemptions
of up to $50,000,000 in the Borrower common stock after September 30, 1995.

         Section 7.18. Total Funded Debt to Cash Flow Ratio. The Borrower will
not permit the Total Funded Debt to Cash Flow Ratio to exceed 5.0 to 1.0 at the
end of any fiscal quarter.

         Section 7.19. Restricted Investments and Contingent Obligations. The
Borrower and its Subsidiaries shall not make, retain or have outstanding a
Restricted Investment (including, without limitation, those listed on Schedule
7.19 hereto) or a Contingent Obligation to the extent that the sum of all
Restricted Investments and all Contingent Obligations of the Borrower and its
Subsidiaries, computed on a consolidated basis in accordance with GAAP, except
as otherwise expressly provided in the definition of Restricted Investment,
would exceed $10,000,000 plus 35% of Adjusted Consolidated Net Worth.

         Section 7.20. Subsidiary Debt. No Subsidiary shall incur any Debt or
any Guaranty of Indebtedness of any other Person of the type described in
clauses (i)-(v) or (viii) of the definition of Debt except (x) Debt to the
Borrower or any other Subsidiary and (y) additional Debt and Guaranties of such
type of such Subsidiaries (computed without duplication) in an aggregate
outstanding principal amount not to exceed 10% of Adjusted Consolidated Net
Worth, in all cases under these clauses (x) and (y) incurred in the ordinary
course of business. 

SECTION 8. EVENTS OF DEFAULT AND REMEDIES.

         Section 8.1. Events of Default. Any one or more of the following shall
constitute an Event of Default:

                  (a) default in the payment when due of the principal amount of
         any Loan or of any Reimbursement Obligation, or default for a period of
         three (3) days in the payment when due of any other obligation
         hereunder;

                  (b) default by the Borrower in the observance or performance
         of any covenant set forth in Sections 7.1, 7.7, 7.9 (except as provided
         in Section 8.1(d) below), 7.13, 7.14(b) and 7.15-7.19;

                  (c) default by the Borrower in the observance or performance
         of the covenant set forth in Section 7.20, which is not remedied within
         ninety (90) days;

                  (d) default by the Borrower (i) in the observance or
         performance of any covenant set forth in Section 7.9 hereof to the
         extent the relevant Lien was not created through any agreement of, or
         through any judgment or other judicial order against, the Borrower or
         Subsidiary or (ii) in the observance or performance of any other



                                      -63-
<PAGE>   43

         provision hereof or of any other Credit Document not mentioned in (a),
         (b) or (c) above, which is not remedied within thirty (30) days after
         notice thereof to the Borrower by the Agent;

                  (e) (i) default shall occur in the payment when due of any
         Indebtedness or Contingent Obligation in an aggregate principal amount
         of $1,000,000 or more of the Borrower or any Subsidiary or (ii) default
         shall occur under any indenture, agreement or other instrument under
         which any Indebtedness or Contingent Obligation of the Borrower or any
         Subsidiary in an aggregate principal amount of $5,000,000 or more may
         be issued or created and such default shall continue for a period of
         time sufficient to permit the holder or beneficiary of such
         Indebtedness or Contingent Obligation or a trustee therefor to cause
         the acceleration of the maturity of any such Indebtedness or Contingent
         Obligation or any mandatory unscheduled prepayment, purchase or funding
         thereof;

                  (f) any representation or warranty made herein or in any other
         Credit Document by the Borrower, or in any statement or certificate
         furnished pursuant hereto or pursuant to any other Credit Document by
         the Borrower, or in connection with any Credit Event proves untrue in
         any material respect as of the date of the issuance or making, or
         deemed making or issuance, thereof;

                  (g) the Borrower or any Subsidiary shall (i) have entered
         involuntarily against it an order for relief under the United States
         Bankruptcy Code, as amended, (ii) not pay, or admit in writing its
         inability to pay, its debts generally as they become due, (iii) make an
         assignment for the benefit of creditors, (iv) apply for, seek, consent
         to, or acquiesce in, the appointment of a receiver, custodian, trustee,
         examiner, liquidator or similar official for it or any substantial part
         of its property, (v) institute any proceeding seeking to have entered
         against it an order for relief under the United States Bankruptcy Code,
         as amended, to adjudicate it insolvent, or seeking dissolution, winding
         up, liquidation, reorganization, arrangement, adjustment or composition
         of it or its debts under any law relating to bankruptcy, insolvency or
         reorganization or relief of debtors or fail to file an answer or other
         pleading denying the material allegations of any such proceeding filed
         against it, (vi) take any corporate action in furtherance of any matter
         described in parts (i)-(v) above, or (vii) fail to contest in good
         faith any appointment or proceeding described in Section 8.1(h) hereof;

                  (h) a custodian, receiver, trustee, examiner, liquidator or
         similar official shall be appointed for the Borrower or any Subsidiary
         or any substantial part of any of their Property, or a proceeding
         described in Section 8.1(g)(v) shall be instituted against the Borrower
         or any Subsidiary, and such appointment continues undischarged or such
         proceeding continues undismissed or unstayed for a period of sixty (60)
         days;

                  (i) the Borrower or any Subsidiary shall fail within thirty
         (30) days to pay, bond or otherwise discharge any judgment or order for
         the payment of money in excess of $5,000,000, which is not stayed on
         appeal or otherwise being appropriately contested in good faith;



                                      -64-
<PAGE>   44

                  (j) the Borrower or any ERISA Affiliate shall fail to pay when
         due an amount or amounts aggregating in excess of $5,000,000 which it
         shall have become liable to pay to the PBGC or to a Plan under Title IV
         of ERISA; or notice of intent to terminate a Plan or Plans having
         aggregate Unfunded Vested Liabilities in excess of $5,000,000
         (collectively, a "Material Plan") shall be filed under Title IV of
         ERISA by the Borrower, any ERISA Affiliate, any plan administrator or
         any combination of the foregoing; or the PBGC shall institute
         proceedings under Title IV of ERISA to terminate or to cause a trustee
         to be appointed to administer any Material Plan or a proceeding shall
         be instituted by a fiduciary of any Material Plan against the Borrower
         or any ERISA Affiliate to enforce Section 515 or 4219(c)(5) of ERISA
         and such proceeding shall not have been dismissed within thirty (30)
         days thereafter; or a condition shall exist by reason of which the PBGC
         would be entitled to obtain a decree adjudicating that any Material
         Plan must be terminated;

                  (k) any person or group of persons (within the meaning of
         Section 13 or 14 of the Securities and Exchange Act of 1934, as
         amended) shall acquire legal or beneficial ownership (within the
         meaning of Rule 13d-3 promulgated by the SEC under said Act) of 30% or
         more in voting power of the outstanding Voting Stock of the Borrower (a
         "Change of Control"); or

                  (l) an "event of default" (as defined therein) shall occur
         under any Bond Document, if it permits the Bond Letter of Credit Issuer
         to declare an early expiration date for a Bond Letter of Credit,
         accelerate the Bonds secured by a Bond Letter of Credit, not reinstate
         any interest component of a Bond Letter of Credit or take any similar
         action or remedy under a Reimbursement Agreement.

         Section 8.2. Non-Bankruptcy Defaults. When any Event of Default other
than those described in Sections 8.1(g) or (h) hereof has occurred and is
continuing, the Agent shall, by notice to the Borrower, (a) if so directed by
the Required Banks, terminate the remaining Commitments and all other
obligations of the Banks to the Borrower hereunder on the date stated in such
notice (which may be the date thereof); (b) if so directed by the Required
Banks, declare the principal of and the accrued interest on all outstanding
Notes of the Borrower to be forthwith due and payable and thereupon all of said
Notes, including both principal and interest, shall be and become immediately
due and payable together with all other amounts payable under this Agreement
without further demand, presentment, protest or notice of any kind; and (c) if
so directed by the Required Banks, demand that the Borrower immediately pay to
the Agent the full amount then available for drawing under each or any Letter of
Credit, and the Borrower agrees to immediately make such payment and
acknowledges and agrees that the Banks would not have an adequate remedy at law
for failure by the Borrower to honor any such demand and that the Agent, for the
benefit of the Banks, shall have the right to require the Borrower to
specifically perform such undertaking whether or not any drawings or other
demands for payment have been made under any Letter of Credit. The Agent, after
giving notice to the Borrower pursuant to Section 8.1 or this Section 8.2, shall
also promptly send a copy of such notice to the other Banks, but the failure to
do so shall not impair or annul the effect of such notice.



                                      -65-
<PAGE>   45

         Section 8.3. Bankruptcy Defaults. When any Event of Default described
in subsection (g) or (h) of Section 8.1 hereof has occurred and is continuing,
then all outstanding Notes shall immediately become due and payable together
with all other amounts payable under this Agreement without presentment, demand,
protest or notice of any kind, the obligation of the Banks to extend further
credit pursuant to any of the terms hereof shall immediately terminate, and the
Borrower shall immediately pay to the Agent the full amount then available for
drawing under all outstanding Letters of Credit, the Borrower acknowledging
that the Banks would not have an adequate remedy at law for failure by the
Borrower to honor any such demand and that the Banks, and the Agent on their
behalf, shall have the right to require the Borrower to specifically perform
such undertaking whether or not any drawings or other demands for payment
have been made under any of the Letters of Credit.

         Section 8.4. Collateral for Undrawn Letters of Credit. (a) If the
prepayment of the amount available for drawing under any or all outstanding
Letters of Credit is required under Section 1.2(b) or under Section 8.2 or 8.3
above, the Borrower shall forthwith pay the amount required to be so prepaid, to
be held by the Agent as provided in subsection (b) below.

         (b) All amounts prepaid pursuant to subsection (a) above shall be held
by the Agent in a separate collateral account (such account, and the credit
balances, properties and any investments from time to time held therein, and any
substitutions for such account, any certificate of deposit or other instrument
evidencing any of the foregoing and all proceeds of and earnings on any of the
foregoing being collectively called the "Account") as security for, and for
application by the Agent (to the extent available) to, the reimbursement of any
payment under any Letter of Credit then or thereafter made by an Issuing Bank,
and to the payment of the unpaid balance of any Loans and all other obligations
of the Borrower hereunder. The Account shall be held in the name of and subject
to the exclusive dominion and control of the Agent for the benefit of the Agent,
the Issuing Banks and the other Banks. If and when requested by the Borrower,
the Agent shall invest funds held in the Account from time to time in direct
obligations of, or obligations the principal of and interest on which are
unconditionally guaranteed by, the United States of America with a remaining
maturity of one year or less, provided that the Agent is irrevocably authorized
to sell investments held in the Account when and as required to make payments
out of the Account for application to amounts due and owing from the Borrower to
the Agent, the Issuing Bank or the other Banks; provided, however, that if (i)
the Borrower shall have made payment of all such obligations referred to in
subsection (a) above, (ii) all relevant preference or other disgorgement periods
relating to the receipt of such payments have passed, and (iii) no Letters of
Credit, Commitments, Loans or other obligations remain outstanding hereunder,
then the Agent shall repay to the Borrower any remaining amounts held in the
Account.

         (c) As security for the payment when due of all of the Obligations, the
Borrower hereby pledges and assigns to the Agent for the benefit of the Agent
and the Banks (including the Issuing Banks), and grants to the Agent for the
benefit of the Agent and the Banks (including the Issuing Banks), a general lien
on and security interest in and right of set-off against, all of its right,
title and interest in and to the Account.



                                      -66-
<PAGE>   46

         Section 8.5. Bond Letters of Credit. In addition to the remedies
otherwise described in this Section 8 or in any other Credit Document or Bond
Document, upon the occurrence of an Event of Default hereunder, the Agent, at
the request of the Required Banks, shall direct the Bond Letter of Credit Issuer
to exercise one or more of the following rights and remedies: (a) give notice of
the occurrence of an Event of Default hereunder (or of an "event of default"
under the applicable Reimbursement Agreement) to the applicable Trustee
directing an acceleration, redemption or tender of the applicable Bonds, thereby
causing the applicable Bond Letter of Credit to terminate the number of days
thereafter specified in such Bond Letter of Credit; (b) if permitted under the
terms of the applicable Bond Letter of Credit, give notice that an amount drawn
under a Bond Letter of Credit to pay interest on Bonds will not be reinstated;
and/or (c) pursue any rights and remedies provided to the Issuing Bank and/or
the Agent under the Bond Documents. Each Bank acknowledges that if the notice
described in clause (b) of the preceding sentence is not delivered on a timely
basis, the interest component of the applicable Bond Letter of Credit will
reinstate in accordance with its terms.

         Section 8.6. Notice of Default. (a) By Agent. The Agent shall give
notice to the Borrower under Section 8.1(d) hereof promptly upon being requested
to do so by any Bank and shall thereupon notify all the Banks thereof.

         (b) For Issuing Banks. No Issuing Bank shall be deemed to have
knowledge or notice of the occurrence of any Default or Event of Default, unless
such Issuing Bank shall have received written notice from the Agent (or, with
respect to a Default or Event of Default under Section 8.1(m), from any party to
a Bond Document, which notice shall then promptly be delivered by the Issuing
Bank to the Agent). The Bond Letter of Credit Issuer shall take such action with
respect to such Default or Event of Default under the Reimbursement Agreements
and the Bond Documents as shall be requested by the Agent in accordance with
Section 8.5; provided that unless and until such Issuing Bank shall have
received any such request, such Issuing Bank may (but shall not be obligated to)
take such action, or refrain from taking such action, concerning such Default or
Event of Default as it shall deem advisable and in the best interest of the
Banks, except any action resulting in the acceleration, redemption or mandatory
tender of any Bonds or the nonreinstatement of the interest component of any
Bond Letter of Credit, which shall only be taken at the request of the Agent
acting on the instructions of the Required Banks.

         Section 8.7. Expenses. The Borrower agrees to pay to the Agent and each
Bank, and any other holder of any Note outstanding hereunder, all expenses
incurred or paid by the Agent or such Bank or any such holder, including
reasonable attorneys' fees (which may be in-house attorneys) and court costs, in
connection with any Default or Event of Default hereunder or in connection with
the enforcement of any of the terms hereof or of any of the other Credit
Documents.

SECTION 9. CHANGE IN CIRCUMSTANCES.

             Section 9.1. Change of Law. Notwithstanding any other provisions of
this Agreement or any Note, if at any time any change in applicable law or
regulation or in the 



                                      -67-
<PAGE>   47

interpretation thereof makes it unlawful for any Bank to make or continue to
maintain Eurodollar Loans or to give effect to its obligations as contemplated
hereby, such Bank shall promptly give notice thereof to the Borrower and such
Bank's obligations to make or maintain Eurodollar Loans under this Agreement
shall terminate until it is no longer unlawful for such Bank to make or maintain
Eurodollar Loans. The Borrower shall prepay on demand the outstanding principal
amount of any such affected Eurodollar Loans, together with all interest accrued
thereon and all other amounts due and payable to such Bank under this Agreement;
provided, however, subject to all of the terms and conditions of this Agreement,
the Borrower may then elect to borrow the principal amount of the affected
Eurodollar Loans from such Bank by means of Domestic Rate Loans from such Bank
that shall not be made ratably by the Banks but only from such affected Bank.

         Section 9.2. Unavailability of Deposits or Inability to Ascertain, or
Inadequacy of, LIBOR. If on or prior to the first day of any Interest Period for
any Borrowing of Eurodollar Loans:

                  (a) the Agent determines that deposits in United States
         Dollars (in the applicable amounts) are not being offered to it in the
         eurodollar market for such Interest Period, or

                  (b) Banks having 50% or more of the aggregate amount of the
         Commitments (excluding the Commitment of the Agent as a Bank) advise
         the Agent that the LIBOR as determined by the Agent will not adequately
         and fairly reflect the cost to such Banks of funding their Eurodollar
         Loans for such Interest Period, 

then the Agent shall forthwith give notice thereof to the Borrower and the
Banks, whereupon until the Agent notifies the Borrower that the circumstances
giving rise to such suspension no longer exist, which notification the Agent
shall promptly give the Borrower when it determines such circumstances no longer
exist, the obligations of the Banks to make Eurodollar Loans shall be suspended.

         Section 9.3. Increased Cost and Reduced Return. (a) If, on or after the
date hereof, the adoption of any applicable law, rule or regulation, or any
change therein, or any change in the interpretation or administration thereof by
any governmental authority, central bank or comparable agency charged with the
interpretation or administration thereof, or compliance by any Bank (or its
Lending Office), including (if applicable) in its capacity as the Issuing Bank
hereunder, with any request or directive (whether or not having the force of
law) of any such authority, central bank or comparable agency:

                  (i) shall subject any Bank (or its Lending Office) to any tax,
         duty or other charge with respect to its Eurodollar Loans, its Notes,
         its Letter(s) of Credit, or its participation in any thereof, any
         Reimbursement Obligations owed to it, or its obligation to make
         Eurodollar Loans, issue a Letter of Credit, or to participate therein,
         or shall change the basis of taxation of payments to any Bank (or its
         Lending Office) of the principal of or interest on its

                                      -68-
<PAGE>   48
         Eurodollar Loans, Letter(s) of Credit, or participations therein, or
         any other amounts due under this Agreement in respect of its Eurodollar
         Loans, Letter(s) of Credit, or participations therein, any
         Reimbursement Obligations owed to it, or its obligation to make
         Eurodollar Loans, issue a Letter of Credit, or acquire participations
         therein (except for changes in the rate of tax on the overall net
         income of such Bank or its Lending Office); or

                  (ii) shall impose, modify or deem applicable any reserve,
         special deposit or similar requirements (including, without limitation,
         any such requirement imposed by the Board of Governors of the Federal
         Reserve System, but excluding any such requirement included in an
         applicable Eurodollar Reserve Percentage) against assets of, deposits
         with or for the account of, or credit extended by, any Bank (or its
         Lending Office) or shall impose on any Bank (or its Lending Office) or
         on the United States market for certificates of deposit or the
         interbank market any other condition affecting its Eurodollar Loans,
         its Notes, its Letters(s) of Credit, or its participation in any
         thereof, any Reimbursement Obligation owed to it, or its obligation to
         make Eurodollar Loans, to issue a Letter of Credit or to participate
         therein;

and the result of any of the foregoing is to increase the cost to such Bank (or
its Lending Office) of making or maintaining any Eurodollar Loan, issuing or
maintaining a Letter of Credit, or participating therein, or to reduce the
amount of any sum received or receivable by such Bank (or its Lending Office)
under this Agreement or under its Notes with respect thereto, by an amount
deemed by such Bank to be material, then, within fifteen (15) days after demand
by such Bank (with a copy to the Agent), the Borrower shall pay to such Bank
such additional amount or amounts as will compensate such Bank for such
increased cost or reduction.

         (b) If, after the date hereof, any Bank (including as an Issuing Bank)
shall have determined that the adoption of any applicable law, rule or
regulation regarding capital adequacy, or any change therein (including, without
limitation, any revisions in the Final Risk-Based Capital Guidelines of the
Board of Governors of the Federal Reserve System (12 CFR Part 208, Appendix A;
12 CFR Part 225, Appendix A) or of the Office of the Comptroller of the Currency
(12 CFR Part 3, Appendix A), or in any other applicable capital rules heretofore
adopted and issued by any governmental authority), or any change in the
interpretation or administration thereof by any governmental authority, central
bank or comparable agency charged with the interpretation or administration
thereof, or compliance by any Bank (or its Lending Office) with any request or
directive regarding capital adequacy (whether or not having the force of law) of
any such authority, central bank or comparable agency, has or would have the
effect of reducing the rate of return on such Bank's capital, or on the capital
of any corporation controlling such Bank, as a consequence of its obligations
hereunder to a level below that which such Bank could have achieved but for such
adoption, change or compliance (taking into consideration such Bank's policies
with respect to capital adequacy) by an amount deemed by such Bank to be
material, then from time to time, within fifteen (15) days after demand by such
Bank (with a copy to the Agent), the Borrower shall pay to such Bank such
additional amount or amounts as will compensate such Bank for such reduction.



                                      -69-
<PAGE>   49

         (c) A certificate of a Bank setting forth such amount or amounts as
shall be necessary to compensate such Bank or the corporation controlling it as
specified in subsection (b) above shall be delivered to the Borrower (with a
copy to the Agent) and shall be conclusive absent manifest error. The Borrower
shall be obligated to pay each Bank the amount shown as due on any such
certificate delivered by it within 10 Business Days after their receipt of the
same.

         (d) In the event any Bank (including, if applicable, in its capacity as
an Issuing Bank) delivers a certificate pursuant to subsection (c) above or
gives notice under Section 9.1 that it will not fund or maintain Eurodollar
Loans, the Borrower may require, at their expense, such Bank to assign (in
accordance with Section 12.12 hereof) all its interests, rights and obligations
hereunder (including all of its Commitment, the Loans at the time owing to it,
and the Notes and participations in Letters of Credit held by it or, in the case
of an assignment solely of an Issuing Bank's rights and obligations, solely its
rights and obligations in such capacity) to a financial institution specified by
the Borrower (a "Substitute Bank"), provided that (i) such assignment shall not
conflict with or violate any law, rule or regulation or order of any court or
other governmental agency or instrumentality, (ii) the Borrower shall have
received the written consent of the Agent and Issuing Banks (other than the
affected Issuing Bank in the case of an assignment by it in such capacity),
which consent shall not be unreasonably withheld, to such assignment and (iii)
the Borrower shall have paid to the assigning Bank all monies then due to it
under the Credit Documents (including pursuant to this Section 9.3) with the
Substitute Bank purchasing all accrued but not yet due Obligations owed such
assigning Bank.

         (e) Promptly after any Bank becomes aware of any circumstance which
will, in its sole judgment, result in a request for increased compensation
pursuant to Section 9.3(b), such Bank shall notify the Borrower thereof (with a
copy to the Agent). Failure on the part of any Bank so to notify the Borrower or
to demand compensation for any increased costs or reduction in amounts received
or receivable or reduction in return on capital with respect to any period shall
not constitute a waiver of such Bank's right to demand compensation with respect
to such period or any other period. The protection of this Section 9.3 shall be
available to each Bank and Agent regardless of any possible contention of the
invalidity or inapplicability of the law, rule, regulation, guideline or other
change or condition which shall have occurred or been imposed.

         Section 9.4. Lending Offices. Each Bank may, at its option, elect to
make its Loans hereunder at the branch, office or affiliate specified on the
appropriate signature page hereof (each a "Lending Office") for each type of
Loan available hereunder or at such other of its branches, offices or affiliates
as it may from time to time elect and designate in a written notice to the
Borrower and the Agent.

         Section 9.5. Discretion of Bank as to Manner of Funding.
Notwithstanding any other provision of this Agreement, each Bank shall be
entitled to fund and maintain its funding of all or any part of its Loans in any
manner it sees fit, it being understood, however, that for the purposes of this
Agreement all determinations hereunder shall be made as if each Bank had
actually funded and maintained each Eurodollar Loan through the



                                      -70-
<PAGE>   50

purchase of deposits in the eurodollar interbank market having a maturity
corresponding to such Loan's Interest Period and bearing an interest rate equal
to the LIBOR for such Interest Period.

SECTION 10. THE AGENT.

         Section 10.1. Appointment and Authorization of Agent. Each Bank hereby
appoints Bank of Montreal as Agent hereunder and hereby authorizes the Agent to
take such action as Agent on its behalf and to exercise such powers under the
Credit Documents as are delegated to such Agent by the terms hereof, together
with such powers as are reasonably incidental thereto.

         Section 10.2. Agent and Affiliates. The Agent shall have the same
rights and powers under this Agreement and the other Credit Documents as any
other Bank and may exercise or refrain from exercising the same as though it
were not Agent, and the Agent and its affiliates may accept deposits from, lend
money to, and generally engage in any kind of business with the Borrower or any
Affiliate of the Borrower as if it were not an Agent hereunder. The term Bank as
used herein and in all other Credit Documents, unless the context otherwise
clearly requires, includes the Agent in its individual capacity as a Bank.

         Section 10.3. Action by Agent. The obligations of the Agent hereunder
are only those expressly set forth herein. Without limiting the generality of
the foregoing, the Agent shall not be required to take any action with respect
to any Event of Default, except as expressly provided in Sections 8.2, 8.3 and
8.6(a).

         Section 10.4. Consultation with Experts. The Agent may consult with
legal counsel, independent public accountants and other experts selected by it
and shall not be liable for any action taken or omitted to be taken by it in
good faith in accordance with the advice of such counsel, accountants or
experts.

         Section 10.5. Liability of Agent and Issuing Bank; Credit Decision.
Neither the Agent nor any Issuing Bank, nor any of their respective directors,
officers, agents, or employees, shall be liable for any action taken or not
taken by it in connection with this Agreement, any Letter of Credit or any other
Credit Document (i) with the consent or at the request of the Required Banks or
(ii) in the absence of its own gross negligence or willful misconduct. Neither
the Agent nor any Issuing Bank, nor any of their respective directors, officers,
agents or employees, shall be responsible for or have any duty to ascertain,
inquire into or verify (i) any statement, warranty or representation made in
connection with this Agreement, any other Credit Document or any Credit Event;
(ii) the performance or observance of any of the covenants or agreements of the
Borrower contained in any Credit Document; (iii) the satisfaction of any
condition specified in Section 6 hereof, except receipt of items required to be
delivered to it under Section 6; or (iv) the validity, effectiveness or
genuineness of this Agreement, the Notes, any Letter of Credit, any other Credit
Document or any other instrument or writing furnished in connection herewith, or
the perfection, value, worth or collectibility of any Credit Document, and
neither the Agent nor any Issuing Bank makes any representation of any kind or
character with respect to any such matter



                                      -71-
<PAGE>   51

mentioned in this sentence. Neither the Agent nor any Issuing Bank shall incur
any liability by acting in reliance upon any notice, consent, certificate, other
document or statement (whether written or oral) believed by it to be genuine or
to be sent by the proper party or parties. In particular, neither the Agent nor
any Issuing Bank shall have any responsibility for confirming the accuracy of
any Compliance Certificate or other document or instrument received by it
hereunder. The Agent and each Issuing Bank shall each in all cases be fully
justified in failing or refusing to act hereunder unless it shall be indemnified
to its reasonable satisfaction by the Banks against any and all liability and
expense which may be incurred by it by reason of taking or continuing to take
any such action. The Agent may treat the owner of any Note as the holder thereof
until written notice of transfer shall have been filed with the Agent signed by
such owner in form satisfactory to the Agent. Each Bank acknowledges that it has
independently and without reliance on the Agent, any Issuing Bank or any other
Bank and based upon such information, investigations and inquiries as its deems
appropriate made its own credit analysis and decision to extend credit to the
Borrower in the manner set forth herein. It shall be the responsibility of each
Bank to keep itself informed as to the creditworthiness of the Borrower and the
Subsidiaries, and the Agent and Issuing Bank shall not have any liability to any
Bank with respect thereto.

         Section 10.6. Costs and Expenses. Each Bank agrees to reimburse the
Agent for all out-of-pocket costs and expenses suffered or incurred by the Agent
in performing its duties hereunder or in the exercise of any right or power
imposed or conferred upon the Agent hereby, to the extent that the Agent is not
promptly reimbursed for same by the Borrower, all such costs and expenses to be
borne by the Banks ratably in accordance with the amounts of their respective
Percentages.

         Section 10.7. Indemnity. The Banks shall ratably, in accordance with
their Percentages, indemnify and hold the Agent, and its directors, officers,
employees, agents and representatives (including as such any security trustee
therefor) harmless from and against any liabilities, losses, costs or expenses
suffered or incurred by them hereunder or in connection with the transactions
contemplated hereby, regardless of when asserted or arising, except to the
extent they are promptly reimbursed for the same by the Borrower and except to
the extent that any event giving rise to a claim was caused by the gross
negligence or willful misconduct of the party seeking to be indemnified. The
obligations of the Banks under this Section 10.7 and all other parts of this
Section 10 shall survive termination of this Agreement.

         Section 10.8. Resignation of Agent and Successor Agent. The Agent may
resign at any time by giving written notice thereof to the Banks and the
Borrower. Upon any such resignation, the Required Banks shall have the right to
appoint a successor Agent with the consent of the Borrower. If no successor
Agent shall have been so appointed by the Required Banks, and shall have
accepted such appointment, within thirty (30) days after the retiring Agent's
giving of notice of resignation, then the retiring Agent may, on behalf of the
Banks, appoint a successor Agent, which shall be any Bank hereunder or any
commercial bank organized under the laws of the United States of America or of
any State thereof and having a combined capital and surplus of at least
$200,000,000. Upon the acceptance of its appointment as an Agent hereunder, such
successor Agent shall thereupon succeed to and



                                      -72-
<PAGE>   52

become vested with all the rights and duties of the retiring Agent, and the
retiring Agent shall be discharged from its duties and obligations hereunder.
After any retiring Agent's resignation hereunder as Agent, the provisions of
this Section 10 shall inure to its benefit as to any actions taken or omitted to
be taken by it while it was Agent.

SECTION 11. MISCELLANEOUS.

         Section 11.1. Withholding Taxes. (a) Payments Free of Withholding.
Except as otherwise required by law and subject to Section 11.1(b) hereof, each
payment by the Borrower under this Agreement or the Notes shall be made without
withholding for or on account of any present or future taxes (other than overall
net income taxes on the recipient) imposed by or within the jurisdiction in
which the Borrower is domiciled, any jurisdiction from which the Borrower makes
any payment, or any political subdivision or taxing authority thereof or
therein. If any such withholding is so required, the Borrower shall make the
withholding, pay the amount withheld to the appropriate governmental authority
before penalties attached thereto or interest accrues thereon and forthwith pay
such additional amount as may be necessary to ensure that the net amount
actually received by each Bank (including as an Issuing Bank) and the Agent free
and clear of such taxes (including such taxes on such additional amount) is
equal to the amount which that Bank or the Agent (as the case may be) would have
received had such withholding not been made. If the Agent or any Bank pays any
amount in respect of any such taxes, penalties or interest the Borrower shall
reimburse the Agent or such Bank for that payment on demand in the currency in
which such payment was made. If the Borrower pays any such taxes, penalties or
interest, it shall deliver official tax receipts evidencing that payment or
certified copies thereof to the Bank or Agent on whose account such withholding
was made (with a copy to the Agent if not the recipient of the original) on or
before the thirtieth day after payment. If any Bank or the Agent determines it
has received or been granted a credit against or relief or remission for, or
repayment of, any taxes paid or payable by it because of any taxes, penalties or
interest paid by the Borrower and evidenced by such a tax receipt, such Bank or
Agent shall, to the extent it can do so without prejudice to the retention of
the amount of such credit, relief, remission or repayment, pay to the Borrower
such amount as such Bank or Agent determines is attributable to such deduction
or withholding and which will leave such Bank or Agent (after such payment) in
no better or worse position than it would have been in if the Borrower had not
been required to make such deduction or withholding. Nothing in this Agreement
shall interfere with the right of each Bank and the Agent to arrange its tax
affairs in whatever manner it thinks fit nor oblige any Bank or the Agent to
disclose any information relating to its tax affairs or any computations in
connection with such taxes.

         (b) U.S. Withholding Tax Exemptions. Each Bank (including each Issuing
Bank and the Agent in its capacity as a Bank) that is not a United States person
(as such term is defined in Section 7701(a)(30) of the Code) shall submit to the
Borrower and (except for the Agent) to the Agent on or before the earlier of the
date the initial Borrowing is made hereunder and thirty (30) days after the date
hereof, two duly completed and signed copies of either Form 1001 (relating to
such Bank and entitling it to a complete exemption from withholding under the
Code on all amounts to be received by such Bank, including fees,



                                      -73-
<PAGE>   53

pursuant to this Agreement and the Loans) or Form 4224 (relating to all amounts
to be received by such Bank, including fees, pursuant to this Agreement and the
Loans) of the United States Internal Revenue Service. Thereafter and from time
to time, each Bank shall submit to the Borrower and the Agent such additional
duly completed and signed copies of one or the other of such Forms (or such
successor forms as shall be adopted from time to time by the relevant United
States taxing authorities) as may be (i) notified by the Borrower, directly or
through the Agent, to such Bank and (ii) required under then-current United
States law or regulations to avoid or reduce United States withholding taxes on
payments in respect of all amounts to be received by such Bank, including fees,
pursuant to this Agreement or the Loans. Upon the request of the Borrower or the
Agent, each Bank that is a United States person (as such term is defined in
Section 7701(a)(30) of the Code) shall submit to the Borrower and Agent a
certificate to the effect that it is such a United States person.

         (c) Inability of Bank to Submit Forms. If any Bank determines, as a
result of any change in applicable law, regulation or treaty, or in any official
application or interpretation thereof, that it is unable to submit to the
Borrower or Agent any form or certificate that such Bank is obligated to submit
pursuant to subsection (b) of this Section 11.1 or that such Bank is required to
withdraw or cancel any such form or certificate previously submitted or any such
form or certificate otherwise becomes ineffective or inaccurate, such Bank shall
promptly notify the Borrower and Agent of such fact and, without affecting the
Borrower's obligations hereunder, the Bank shall to that extent not be obligated
to provide any such form or certificate and will be entitled to withdraw or
cancel any affected form or certificate, as applicable.

         Section 11.2. No Waiver of Rights. No delay or failure on the part of
the Agent or any Bank or on the part of the holder or holders of any Note in the
exercise of any power or right shall operate as a waiver thereof, nor as an
acquiescence in any default, nor shall any single or partial exercise thereof
preclude any other or further exercise of any other power or right, and the
rights and remedies hereunder of the Agent, the Banks and the holder or holders
of any Notes are cumulative to, and not exclusive of, any rights or remedies
which any of them would otherwise have.

         Section 11.3. Non-Business Day. If any payment of principal or interest
on any Loan shall fall due on a day which is not a Business Day, interest at the
rate such Loan bears for the period prior to maturity shall continue to accrue
on such principal from the stated due date thereof to and including the next
succeeding Business Day, on which the same shall be payable.

         Section 11.4. Documentary Taxes. The Borrower agrees that it will pay
any documentary, stamp or similar taxes payable in respect to this Agreement,
any Note of its or any Letter of Credit, including interest and penalties, in
the event any such taxes are assessed irrespective of when such assessment is
made and whether or not any credit is then in use or available hereunder.



                                      -74-
<PAGE>   54

         Section 11.5. Survival of Representations. All representations and
warranties made herein or in certificates given pursuant hereto shall survive
the execution and delivery of this Agreement and of the Notes and the issuance
of any Letter of Credit, and shall continue in full force and effect with
respect to the date as of which they were made as long as any credit is in use
or available hereunder.

         Section 11.6. Survival of Indemnities. All indemnities and all other
provisions relative to reimbursement to the Banks of amounts sufficient to
protect the yield of the Banks with respect to the Loans and the Letters of
Credit, including, but not limited to, Section 1.11 and Section 9.3 hereof,
shall survive the termination of this Agreement and the payment of the Loans,
the Reimbursement Obligations and the Notes; provided that any Bank seeking
compensation pursuant to Section 1.11 or Section 9.3 hereof shall make a claim
for such compensation no later than six (6) months after the termination of all
Commitments hereunder and the repayment of all Loans and Reimbursement
Obligations.

         Section 11.7. Sharing of Set-Off. Each Bank agrees with each other Bank
a party hereto that if such Bank shall receive and retain any payment, whether
by set-off or application of deposit balances or otherwise ("Set-off"), on any
of the Loans or Reimbursement Obligations in excess of its ratable share of
payments on all such obligations then outstanding to the Banks, then such Bank
shall purchase for cash at face value, but without recourse, ratably from each
of the other Banks such amount of the Loans or Reimbursement Obligations, or
participations therein, held by each such other Bank (or interest therein) as
shall be necessary to cause such Bank to share such excess payment ratably with
all the other Banks; provided, however, that if any such purchase is made by any
Bank, and if such excess payment or part thereof is thereafter recovered from
such purchasing Bank, the related purchases from the other Banks shall be
rescinded ratably and the purchase price restored as to the portion of such
excess payment so recovered, but without interest.

         Section 11.8. Notices. Except as otherwise specified herein, all
notices hereunder shall be in writing (including telecopy or telex) and shall be
given to such party at its address or telecopier number set forth below or such
other address or telecopier number as such party may hereafter specify by notice
to the Agent and the Borrower, given by United States certified or registered
mail, by overnight courier service, by telegram or by other telecommunication
device capable of creating a written record of such notice and its receipt.
Notices hereunder to the Banks and the Agent shall be addressed to their
respective addresses, telecopier and telephone number set forth on the signature
pages hereof, and to the Borrower to:

                          The Allen Group Inc.
                          25101 Chagrin Boulevard
                          Beachwood, Ohio 44122
                          Attention:  Treasurer (with a copy to
                            General Counsel)
                          Telephone:  216-765-5805
                          Telecopy:  216-765-0410



                                      -75-
<PAGE>   55

         Each such notice, request or other communication shall be effective (i)
if given by telecopier, when such telecopy is transmitted to the telecopier
number specified in this Section 11.8 or on the signature pages hereof and a
confirmation of such telecopy has been received by the sender, (ii) if given by
mail, five (5) days after such communication is deposited in the mail,
registered with return receipt requested, addressed as aforesaid or (iii) if
given by any other means (including by overnight courier), when delivered at the
addresses specified in this Section or on the signature pages hereof; provided
that any notice given pursuant to Section 1 or Section 2 shall be effective only
upon receipt.

         Section 11.9. Counterparts. This Agreement may be executed in any
number of counterparts, and by the different parties on different counterparts,
each of which when executed shall be deemed an original but all such
counterparts taken together shall constitute one and the same instrument.

         Section 11.10. Successors and Assigns. This Agreement shall be binding
upon the Borrower and its successors and assigns, and shall inure to the benefit
of each of the Banks and the benefit of their respective successors and assigns,
including any subsequent holder of any Note. The Borrower may not assign any of
its rights or obligations hereunder without the written consent of all of the
Banks, subject to Section 7.13.

         Section 11.11. Participants and Note Assignees. Each Bank shall have
the right at its own cost to grant participations (to be evidenced by one or
more agreements or certificates of participation) in the Loans made, and/or
Commitments held, and the Reimbursement Obligations, or participations therein,
held by such Bank at any time and from time to time, and to assign its rights
under such Loans, or the Notes evidencing such Loans, and/or the Reimbursement
Obligations, or participations therein, to one or more other Persons; provided
that no such participation or assignment shall relieve any Bank of any of its
obligations under this Agreement, and provided further that no such assignee or
participant shall have any rights under this Agreement except as provided in
this Section 11.11, and the Agent shall have no obligation or responsibility to
such participant or assignee, except that nothing herein provided is intended to
affect the rights of an assignee of a Note to enforce the Note assigned. Any
party to which such a participation or assignment has been granted shall have
the benefits of Section 1.11 and Section 9.3 hereof. Any Bank assigning any Note
hereunder shall give prompt notice thereof to the Borrower and the Agent, who
shall in each case only be required to treat such assignee of a Note as the
holder thereof after receipt of such notice.

           Section 11.12. Assignment of Commitments by Banks. Each Bank shall
have the right at any time, with the prior consent of each Issuing Bank and the
Agent, which shall not be unreasonably withheld, to sell, assign, transfer or
negotiate all or any part of its Commitments (including the same percentage of
its Notes, outstanding Loans, participations in Letters of Credit and its other
extensions of credit to the Borrower hereunder) to one or more commercial banks
or other financial institutions that have the capability to fund Loans at the
interest rates provided in this Agreement, provided that the assignee must
assume Commitments of at least $5,000,000; the Percentage so assigned shall
remain constant, not vary by its terms, and shall be the same for all Sections
of this Agreement; and assignments 



                                      -76-
<PAGE>   56

from a Bank to one of its affiliates do not require the consent of either
Issuing Agent or the Agent. Upon any such assignment, its notification to the
Agent, and (except in the case of an assignment by a Bank to an affiliate) the
payment to the Agent of a $2,500 recordation and administration fee, any such
assignee shall become a Bank for all purposes hereunder to the extent of the
Commitments it assumes, and the assigning Bank shall be released from its
obligations, and will have released its rights, hereunder to the extent of such
assignment.

         Section 11.13. Amendments. Any provision of any Credit Document may be
amended or waived if, but only if, such amendment or waiver is in writing and is
signed by (a) the Borrower, (b) the Required Banks, and (c) if the rights or
duties of an Issuing Bank or the Agent are affected thereby, the relevant
Issuing Bank or Agent; provided that:

                  (i) no amendment or waiver pursuant to this Section 11.13
         shall (A) increase any Commitment or Percentage of any Bank without the
         consent of such Bank or (B) reduce the amount of or postpone the date
         for payment of any principal of or interest on any Loan or of any
         Reimbursement Obligation or of any fee payable hereunder without the
         consent of all the Banks;

                  (ii) no amendment or waiver pursuant to this Section shall,
         unless signed by each Bank, change the provisions of this Section
         11.13, the definition of Required Banks, or any condition precedent set
         forth in Section 6 hereof or the provisions of Sections 8.1(g), 8.1(h),
         8.3 or 9, or affect the number of Banks required to take any action
         under this Agreement; and

                  (iii) the Bond Letter of Credit Issuer may enter into any
         amendment or modification of, or may waive compliance with the terms of
         any Bond Document (other than an Indenture), without the consent of any
         Bank; provided that without the consent of all the Banks, the Bond
         Letter of Credit Issuer shall not execute any instrument agreeing to
         any amendment or modification of, or waiver of compliance with any
         Reimbursement Agreement or Bond Document, (i) which would (A) reduce
         the principal of, or interest on, any L/C Obligation, (B) postpone the
         due date for any payment of principal of, or interest on, any L/C
         Obligation, (C) extend the termination date of a Bond Letter of Credit
         beyond the Termination Date, (D) increase the amount of any Bond Letter
         of Credit or otherwise increase in any material manner the obligations
         of the Participating Banks, or (E) release or otherwise adversely
         affect the interests of the Participating Banks in any collateral
         granted under any Reimbursement Agreement or Bond Document, or (ii)
         after the occurrence of a Default or Event of Default of which it has
         notice as provided in Section 8.6(b); provided that (i) at least thirty
         (30) days before extending the termination date of any Bond Letter of
         Credit the Bond Letter of Credit Issuer shall notify the Agent, which
         will then notify each Bank, of such proposed extension and (ii) the
         Bond Letter of Credit Issuer will not waive any "event of default"
         arising under any Reimbursement Agreement or Bond Document without the
         consent of the Required Banks.



                                      -77-
<PAGE>   57

         Section 11.14. Headings. Section headings used in this Agreement are
for reference only and shall not affect the construction of this Agreement.

         Section 11.15. Legal Fees and Indemnification. The Borrower agrees to
pay the reasonable fees and disbursements of Messrs. Chapman and Cutler, counsel
to the Agent, in connection with the preparation and execution of this
Agreement, and any amendment, waiver or consent related hereto, whether or not
the transactions contemplated herein are consummated. The Borrower further
agrees to indemnify each Bank and the Agent, and their respective directors,
officers and employees, against all losses, claims, damages, penalties,
judgments, liabilities and expenses (including, without limitation, all expenses
of litigation or preparation therefor) which any of them may pay or incur
arising out of or relating to this Agreement, any Note, any Letter of Credit,
any drawing thereunder, any of the transactions contemplated hereby or thereby
or the direct or indirect application or proposed application of the proceeds of
any Loan or Credit Document, other than those which arise from the gross
negligence or willful misconduct of the party claiming indemnification. The
Borrower, upon demand by the Agent or a Bank at any time, shall reimburse the
Agent or such Bank for any legal or other expenses incurred in connection with
investigating or defending against any of the foregoing except if the same is
directly due to the gross negligence or willful misconduct of the party to be
indemnified or to any breach of an express contractual obligation owed by the
party to be indemnified; provided, however, that (i) the Borrower shall not, in
connection with any such proceeding or related proceedings in the same
jurisdiction, be liable for the reasonable fees and expenses of more than one
separate law firm for the Banks and the Agent (which shall be selected by the
Agent after consultation with the Borrower), (ii) the Agent and each Bank shall
consult with the Borrower from time to time at the request of the Borrower
regarding the conduct of the defense in any such proceeding and will cooperate
with the Borrower in its joining as parties to any such proceeding to the extent
the Borrower is permitted by law to join such litigation, and (iii) the Borrower
shall not be obligated to pay an amount of any settlement entered into without
its consent (which shall not be unreasonably withheld). The obligations of the
Borrower under this Section 11.15 shall survive the termination of this
Agreement.

         Section 11.16. Governing Law. This Agreement and the Notes, and the
rights and duties of the parties hereto, shall be construed and determined in
accordance with the internal laws of the State of Illinois.

         Section 11.17. Entire Agreement. This Agreement and the other Credit
Documents constitute the entire understanding of the parties hereto with respect
to the subject matter hereof and thereof and any prior or contemporaneous
agreements, whether written or oral, with respect thereto are superseded hereby.


                                      -78-
<PAGE>   58

         Upon your acceptance hereof in the manner hereinafter set forth, this
Agreement shall be a contract between us for the purposes hereinabove set forth.

Dated as of November 11, 1996.

                                       THE ALLEN GROUP INC.

                                       By___________________________
                                         Its________________________

                                       By___________________________
                                         Its________________________

                                       MARTA TECHNOLOGIES, INC., solely to
                                         confirm its withdrawal as a "Borrower" 
                                         under the Original Credit Agreement

                                       By___________________________
                                         Its________________________

        Accepted and Agreed to as of the day and year last above written.

Address and Amount of Commitments:

Address: 115 S. LaSalle Street         BANK OF MONTREAL, CHICAGO
         Chicago, Illinois 60603         BRANCH, in its individual
         Attn:  Erin Keyser              capacity as a Bank and as Agent
                                       
Telecopy:  (312) 750-4314              
Telephone:  (312) 750-5943             By___________________________
                                         Its________________________ 
                                       
Commitment:  $21,164,855.04
Participation in Bond Letters of Credit:  $4,005,213.00
Percentage:  25.17006804%

Lending Offices:

                 115 S. LaSalle Street
                 Chicago, IL 60603


                                      -79-
<PAGE>   59




Address: 231 S. LaSalle Street                BANK OF AMERICA ILLINOIS, in its
         Chicago, IL 60697                     capacities as a Bank, as an
         Attn:  Paul B. Higdon                 Issuing Bank, and as Co-Agent

Telecopy:  (312) 987-5833
Telephone:  (312) 828-7952
                                              By___________________________ 
                                                Its________________________
                                              
Commitment:  $14,300,577.72
Participation in Bond Letters of Credit:  $2,706,225.00
Percentage:  17.00680272%

Lending Offices:

                 231 S. LaSalle Street
                 Chicago, IL 60697


                                      -80-
<PAGE>   60


                                              KEYBANK NATIONAL ASSOCIATION
Address:  127 Public Square
          01-127-0606
          Cleveland, OH 44114-1306
          Attn:  Lawrence Mack

Telecopy:  (216) 689-4981
Telephone:  (216) 689-4330                    By___________________________ 
                                                Its________________________ 

Commitment:  $14,300,577.72
Participation in Bond Letters of Credit:  $2,706,225.00
Percentage:  17.00680272%

Lending Offices:

                127 Public Square
                Cleveland, OH 44114-1306


                                      -81-
<PAGE>   61




                                               BAYERISCHE VEREINSBANK AG,
                                                CHICAGO BRANCH

Address:  333 W. Wacker Drive, Suite 680
          Chicago, Illinois 60606
          Attn:  Kendal Baker, Vice President  By___________________________ 
                                                 Its________________________ 

Telecopy:  (312) 368-8615
Telephone:  (312) 368-3313

Commitment:  $8,580,346.63 By
Participation in Bond Letters of Credit: 
  $1,623,735.00                                By___________________________ 
Percentage:  10.20408163%                        Its________________________ 

Lending Offices:

               333 W. Wacker Drive, Suite 680
               Chicago, IL 60606


                                      -82-
<PAGE>   62




                                           DRESDNER BANK AG, New York
                                             and Grand Cayman Branches, in its
                                             capacities as a Bank and as an
Address:  75 Wall Street                     Issuing Bank
          New York, New York 10005   
          Attn:  Anthony Berti

                                           By
                                             -----------------------------
                                           Its
                                              ----------------------------
Telecopy:  (212) 429-2129                  
Telephone:  (212) 429-2247

                                           By
                                             -----------------------------
                                           Its
                                              ----------------------------
Commitment:  $8,580,346.63
Participation in Bond Letters of Credit:  $1,623,735.00
Percentage:  10.20408163%

Lending Offices:         Domestic Rate Loans:

                         75 Wall Street
                         New York, New York 10005

                         Eurodollar Loans:



                         Grand Cayman Branch
                         c/o New York Branch
                         75 Wall Street
                         New York, New York 10005


                                      -83-
<PAGE>   63


                                                    NATIONSBANK OF TEXAS, N.A.

Address:  901 Main Street
          64th Floor
          Dallas, Texas 75202
          Attn:  W. Hutchinson McClendon, IV        By
                                                      --------------------------
                                                    Its
                                                       -------------------------
Telecopy:  (214) 508-9390
Telephone:  (214) 508-0996

Commitment:  $8,580,346.63
Participation in Bond Letters of Credit:  $1,623,735.00
Percentage:  10.20408163%

Lending Offices:

                         901 Main Street
                         64th Floor
                         Dallas, Texas 75202


                                      -84-
<PAGE>   64



                                                    NBD BANK

Address:  611 Woodward
          Detroit, Michigan 48266
          Attn:  Andrew W. Strait, Vice President

Telecopy:  (313) 225-3269
Telephone:  (313) 225-3300                          By
                                                      --------------------------
                                                    Its
                                                       -------------------------
Commitment:  $8,580,346.63
Participation in Bond Letters of Credit:  $1,623,735.00
Percentage:  10.20408163%

Lending Offices:  611 Woodward
                  Detroit, Michigan 48266


                                      -85-