<PAGE>

                                                                     EXHIBIT 4.1

 
                             REVOLVING CREDIT AND
                      LETTER OF CREDIT ISSUANCE AGREEMENT



                                 By and Among



                            PITT-DES MOINES, INC.,
                                  as Borrower

                                      and

                   THE FINANCIAL INSTITUTIONS PARTY HERETO,
                                  as Lenders

                                      and

                        PNC BANK, NATIONAL ASSOCIATION,
                as Agent, as L/C Issuer and as Swingline Lender



                         Dated as of February 16, 1999
<PAGE>
 
                               TABLE OF CONTENTS

<TABLE>
<C>            <S>                                                                                                          <C> 
 
SCHEDULES................................................................................................................   iv

EXHIBITS.................................................................................................................   v
 
ARTICLE I      CERTAIN DEFINITIONS; CONSTRUCTION.........................................................................    1
       1.01.   Certain Definitions.......................................................................................    1
       1.02.   Construction..............................................................................................   16
       1.03.   Accounting Principles.....................................................................................   17
 
ARTICLE II     REVOLVING CREDIT FACILITY.................................................................................   18
 
       2.01.   Revolving Credit Commitments..............................................................................   18
       2.02.   Nature of Lenders' Obligations with Respect to Revolving Credit Loans.....................................   18
       2.03.   Commitment Fees...........................................................................................   18
       2.04.   Voluntary Reduction of Revolving Credit Commitments.......................................................   19
       2.05.   Revolving Credit Loan Requests............................................................................   19
       2.06.   Making Revolving Credit Loans.............................................................................   20
       2.07.   Revolving Credit Notes....................................................................................   20
       2.08.   Interest Payments, Interest Rates and Certain Related Payments Pertaining to the Revolving Credit Loans...   20
       2.09.   Prepayments: Allocation of Repayments.....................................................................   24
       2.10.   Yield Protection..........................................................................................   24
       2.11.   Special Provisions Relating to the Euro-Rate Option.......................................................   26
       2.12.   Capital Adequacy..........................................................................................   28
       2.13.   Swingline Loans...........................................................................................   28
       2.14    Loan Account..............................................................................................   29
       2.15.   All Advances to Constitute One Loan.......................................................................   30
       2.16.   Use of Proceeds...........................................................................................   30
       2.17.   Letter of Credit Subfacility..............................................................................   30
       2.18.   Taxes.....................................................................................................   37
       2.19.   Payments..................................................................................................   39
 
ARTICLE III    LOAN DISBURSEMENT ACCOUNT, GUARANTEES, ETC................................................................   39
 
       3.01.   Loan Disbursement Account.................................................................................   39
       3.02.   Designation of Subsidiary Guarantors......................................................................   39
       3.03.   Further Cooperation.......................................................................................   40
 
ARTICLE IV     REPRESENTATIONS AND WARRANTIES............................................................................   40
 
       4.01.   Organization and Qualification............................................................................   40
       4.02.   Capitalization and Ownership..............................................................................   40
       4.03.   Subsidiaries..............................................................................................   40
       4.04.   Power and Authority.......................................................................................   41
       4.05.   Validity and Binding Effect...............................................................................   41
       4.06.   No Conflict...............................................................................................   41
       4.07.   Litigation................................................................................................   41
       4.08.   Financial Statements......................................................................................   42
       4.09.   Margin Stock; Section 20 Subsidiaries.....................................................................   42
       4.10.   Full Disclosure...........................................................................................   42
</TABLE> 

                                       i
<PAGE>
 
<TABLE>
<C>            <S>                                                                                                          <C> 
 
       4.11.   Tax Returns and Payments..................................................................................   42
       4.12.   Consents and Approvals....................................................................................   43
       4.13.   No Event of Default; Compliance with Instruments..........................................................   43
       4.14.   Compliance with Laws......................................................................................   43
       4.15.   Investment Company; Public Utility Holding Company........................................................   43
       4.16.   Plans and Benefit Arrangements............................................................................   44
       4.17.   Title to Properties.......................................................................................   45
       4.18.   Insurance.................................................................................................   45
       4.19.   Employment Matters........................................................................................   45
       4.20.   Environmental Matters.....................................................................................   45
       4.21.   Senior Debt Status........................................................................................   46
       4.22.   Solvency..................................................................................................   47
       4.23.   Material Contracts; Burdensome Restrictions...............................................................   47
       4.24.   Patents, Trademarks, Copyrights, Licenses, etc............................................................   47
       4.25.   Brokers...................................................................................................   47
       4.26.   No Material Adverse Change................................................................................   47
       4.27.   Year 2000 Problem.........................................................................................   47
 
ARTICLE V      CONDITIONS OF LENDING OR ISSUANCE OF LETTER OF CREDIT.....................................................   47
 
       5.01.   Conditions to Initial Borrowings..........................................................................   48
       5.02.   Each Additional Revolving Credit Loan, Swingline Loan or Issuance of a Letter of Credit...................   50
       5.03.   Location of Closing.......................................................................................   51
 
ARTICLE VI     AFFIRMATIVE COVENANTS.....................................................................................   52
 
       6.01.   Preservation of Existence, Etc............................................................................   52
       6.02.   Accounting System; Reporting Requirements.................................................................   52
       6.03.   Notices Regarding Plans and Benefit Arrangements..........................................................   54
       6.04.   Payment of Liabilities, Including Taxes, etc..............................................................   55
       6.05.   Maintenance of Insurance..................................................................................   55
       6.06.   Maintenance of Properties and Leases......................................................................   55
       6.07.   Maintenance of Permits and Franchises.....................................................................   55
       6.08.   Visitation Rights.........................................................................................   56
       6.09.   Keeping of Records and Books of Account...................................................................   56
       6.10.   Plans and Benefit Arrangements............................................................................   56
       6.11.   Compliance with Laws......................................................................................   56
       6.12.   Use of Proceeds...........................................................................................   56
       6.13.   Environmental Laws........................................................................................   56
       6.14.   Senior Debt Status........................................................................................   57
 
ARTICLE VII    NEGATIVE COVENANTS........................................................................................   57
 
       7.01.   Indebtedness..............................................................................................   57
       7.02.   Liens; Negative Pledge....................................................................................   58
       7.03.   Loans, Acquisitions and Investments.......................................................................   58
       7.04.   Liquidations, Mergers and Consolidations..................................................................   59
       7.05.   Dispositions of Assets or Subsidiaries....................................................................   60
       7.06.   Affiliate Transactions....................................................................................   60
       7.07.   Subsidiaries, Partnerships and Joint Ventures.............................................................   60
       7.08.   Continuation of or Change in Business.....................................................................   60
       7.09.   Plans and Benefit Arrangements............................................................................   61
</TABLE> 

                                       ii
<PAGE>
 
<TABLE>
<C>            <S>                                                                                                          <C> 
       7.10.   Fiscal Year...............................................................................................   61
       7.11.   Changes in Organizational Documents.......................................................................   61
       7.12.   Financial Covenants.......................................................................................   61
       7.13.   Operating Leases..........................................................................................   62
       7.14.   Stock Repurchase..........................................................................................   62
 
ARTICLE VIII   DEFAULT...................................................................................................   62
 
       8.01.   Events of Default.........................................................................................   62
       8.02.   Consequences of Event of Default..........................................................................   65
 
ARTICLE IX     THE AGENT.................................................................................................   67
 
       9.01.   Appointment and Grant of Authority........................................................................   67
       9.02.   Delegation of Duties......................................................................................   67
       9.03.   Reliance by Agent on Lenders for Funding..................................................................   67
       9.04.   Non-Reliance on Agent.....................................................................................   68
       9.05.   Responsibility of Agent and Other Matters.................................................................   68
       9.06.   Actions in Discretion of Agent; Instructions from the Lenders.............................................   69
       9.07.   Indemnification...........................................................................................   69
       9.08.   Agent's Rights as Lender..................................................................................   69
       9.09.   Notice of Default.........................................................................................   70
       9.10.   Payment to Lenders........................................................................................   70
       9.11.   Holders of Notes..........................................................................................   70
       9.12.   Equalization of Lenders...................................................................................   70
       9.13.   Successor Agent...........................................................................................   71
       9.14.   Calculations..............................................................................................   71
       9.15.   Beneficiaries.............................................................................................   71
 
ARTICLE X      GENERAL PROVISIONS........................................................................................   71
 
      10.01.   Amendments and Waivers....................................................................................   71
      10.02.   Taxes.....................................................................................................   72
      10.03.   Costs and Expenses, etc...................................................................................   72
      10.04.   Notices...................................................................................................   73
      10.05.   Participation and Assignment..............................................................................   75
      10.06.   Successors and Assigns....................................................................................   77
      10.07.   No Implied Waivers; Cumulative Remedies; Writing Required.................................................   77
      10.08.   Severability..............................................................................................   77
      10.09.   Indemnity.................................................................................................   77
      10.10.   Confidentiality...........................................................................................   78
      10.11.   Survival..................................................................................................   78
      10.12.   GOVERNING LAW.............................................................................................   79
      10.13.   FORUM.....................................................................................................   79
      10.14.   Non-Business Days.........................................................................................   79
      10.15.   Integration...............................................................................................   79
      10.16.   Counterparts..............................................................................................   79
      10.17.   Funding by Branch, Subsidiary or Affiliate................................................................   80
      10.18.   WAIVER OF JURY TRIAL......................................................................................   80
</TABLE>

                                      iii
<PAGE>
 
                                   SCHEDULES


     Schedule 1.01(a)   Lenders; Commitments
     Schedule 2.17(j)   Assumed Letters of Credit
     Schedule 3.02      Subsidiary Guarantors
     Schedule 4.01      Jurisdictions of Incorporation and Qualification of
                        Borrower
     Schedule 4.02      Capital Stock Options
     Schedule 4.03      Interests in Subsidiaries and Other Entities
     Schedule 4.07      Litigation
     Schedule 4.11      Agreements Concerning Tax Returns
     Schedule 4.12      Consents and Approvals
     Schedule 4.16      Plans and Benefit Arrangements
     Schedule 4.20      Environmental Matters
     Schedule 7.01      Permitted Indebtedness
     Schedule 7.03      Other Investments
     Schedule 7.06      Affiliate Transactions

                                       iv
<PAGE>
 
                                 EXHIBITS


Exhibit "A-1"    Form of Revolving Credit Note
Exhibit "A-2"    Form of Swingline Note
Exhibit "B"      Form of Loan Request
Exhibit "C"      Form of Subsidiary Guaranty
Exhibit "D"      Form of Compliance Certificate
Exhibit "E-1"    Form of Opinion of Counsel - BIPC
Exhibit "E-2"    Form of Opinion of Counsel - PDM
Exhibit "F"      Form of Assignment and Assumption Agreement

                                       v
<PAGE>
 
                             REVOLVING CREDIT AND
                      LETTER OF CREDIT ISSUANCE AGREEMENT


          THIS REVOLVING CREDIT AND LETTER OF CREDIT ISSUANCE AGREEMENT, dated
as of February 16, 1999 is made by and among PITT-DES MOINES, INC., a
Pennsylvania corporation (as more fully defined below, the "BORROWER"), the
Lenders (as hereinafter defined), and PNC BANK, NATIONAL ASSOCIATION, in its
capacity as L/C Issuer (as hereinafter defined), as Swingline Lender (as
hereinafter defined) and as agent for the L/C Issuer, the Swingline Lender and
the Lenders under this Agreement (in such capacity, as more fully defined below,
the "AGENT").

                                  WITNESSETH:

          WHEREAS, the Borrower has requested the Lenders to make available to
the Borrower Revolving Credit Loans in an aggregate principal amount not
exceeding Seventy Million Dollars ($70,000,000) at any one time outstanding; and
the Borrower has requested the Lenders to provide for the issuance for the
account of the Borrower Letters of Credit with an aggregate Stated Amount not
exceeding Thirty Million Dollars ($30,000,000) at any one time outstanding;
provided that at no time will Total Utilization exceed Seventy Million Dollars
($70,000,000); and

          WHEREAS, the Lenders are willing to make the Revolving Credit Loans
available to the Borrower upon the terms and conditions hereinafter set forth;
the Swingline Lender is willing to make the Swingline Option available to the
Borrower upon the terms and conditions hereinafter set forth; and the L/C Issuer
is willing to issue Letters of Credit for the account of the Borrower upon the
terms and conditions hereinafter set forth; and the Lenders are willing to
purchase risk participations with respect to each Letter of Credit issued by the
L/C Issuer hereunder upon the terms and conditions hereinafter set forth.

          NOW, THEREFORE, in consideration of the premises (each of which is
incorporated herein by reference) and the mutual covenants and agreements
hereinafter set forth, and other valuable consideration, and intending to be
legally bound hereby, the parties hereto hereby covenant and agree as follows:

                                   ARTICLE I
                       CERTAIN DEFINITIONS; CONSTRUCTION

          1.01.  Certain Definitions. In addition to words and terms defined
elsewhere in this Agreement, the following words and terms shall have the
following meanings, respectively, unless the context hereof clearly requires
otherwise:

          Affiliate as to any Person shall mean any other Person (i) which
directly or indirectly Controls, is Controlled by, or is under common Control
with such Person, (ii) which beneficially owns or holds 5% or more of any class
of the voting or other equity interests of such Person, or (iii) 5% or more of
any class of voting interests or other equity interests of which is beneficially
owned or held, directly or indirectly, by such Person.

          Agent shall mean PNC Bank, National Association, a national banking
association organized under the laws of the United States of America, in its
capacity as agent 

                                       1
<PAGE>
 
for the L/C Issuer, the Swingline Lender and the Lenders pursuant to this
Agreement, and its successors and assigns in such capacity.

          Agent's Fee shall mean the annual fee payable to the Agent for acting
as Agent hereunder, all as more fully set forth in the Agent's Letter.

          Agent's Letter shall mean the letter from the Agent to the Borrower
dated as of the Closing Date, as the same may be amended or otherwise modified
or supplemented.

          Agreement shall mean this Revolving Credit and Letter of Credit
Issuance Agreement, as the same may be supplemented or amended from time to
time, including all schedules and exhibits hereto.

          Applicable Base Rate Margin shall have the meaning ascribed to it in
Section 2.08(b)(iii) of this Agreement.

          Applicable Commitment Fee shall have the meaning ascribed to it in
Section 2.03 hereof.

          Applicable Euro-Rate Margin shall have the meaning ascribed to it in
Section 2.08(b)(iii) of this Agreement.

          Applicable Letter of Credit Fee shall have the meaning ascribed to it
in Section 2.17(b) of this Agreement.

          Application for Letter of Credit shall mean the then current
application agreement for a standby letter of credit or for an amendment
thereto, as in effect from time to time by the L/C Issuer.

          Assignment and Assumption Agreement shall mean an Assignment and
Assumption Agreement by and among a Purchasing Lender, a Transferor Lender and
the Agent, as the Agent and on behalf of the remaining Lenders, substantially in
the form of Exhibit "F" hereto.

          Assignment Fee shall mean the fee described in Section 10.05(b).

          Authorized Officer shall mean those persons designated initially in
the several incumbency certificates delivered pursuant to Section 5.01 hereof by
the Borrower or a Subsidiary Guarantor, as the case may be. The Borrower, or a
Subsidiary Guarantor, as the case may be, may amend such list of persons from
time to time by giving written notice of such amendment to the Agent.

          Availability shall mean, as of any time of determination the positive
difference between the Revolving Credit Commitments and Total Utilization.

          Base Rate shall mean the greater of (i) the Prime Rate, or (ii) the
Federal Funds Effective Rate plus fifty basis points (1/2 of 1%) per annum.

          Base Rate Option shall mean the interest rate option described in
Section 2.08(b)(i) hereof.

                                       2
<PAGE>
 
          Base Rate Portion shall mean the portion of the Revolving Credit Loans
or the Swingline Loan; which bears, or is to bear, interest under the Base Rate
Option.

          Benefit Arrangement shall mean at any time an "employee benefit plan",
within the meaning of Section 3(3) of ERISA, which is neither a Plan nor a
Multiemployer Plan and which is maintained, sponsored or otherwise contributed
to, by any member of the ERISA Group.

          Borrower shall mean PITT-DES MOINES, INC., a corporation organized and
existing under the laws of the Commonwealth of Pennsylvania, and its successors
and permitted assigns.

          Borrowing Date shall mean, with respect to any Revolving Credit Loan
or any Swingline Loan, the date for the making thereof, or as to Revolving
Credit Loans, the renewal or conversion thereof at or to the same or a different
Interest Rate Option, which shall be a Business Day.

          Business Day shall mean (i) any day other than a Saturday or Sunday or
a legal holiday on which commercial banks in Pittsburgh, Pennsylvania are
authorized or required to be closed under the laws of the Commonwealth of
Pennsylvania, federal law or other applicable Law of an Official Body, and (ii)
if the applicable Business Day relates to any day for the determination of any
Euro-Rate, any day that satisfies the conditions of clause (i) above provided
that such day is a day on which dealings in Dollar deposits are carried on in
the London interbank market.

          Capital Adequacy Event shall have the meaning ascribed to it in
Section 2.12 hereof.

          Capital Compensation Amount shall have the meaning ascribed to it in
Section 2.12 hereof.

          Cash Collateral Account shall have the meaning ascribed to it in
Section 8.02(e) hereof.

          Cash Equivalents shall mean (i) securities issued or directly and
fully guaranteed or insured by the United States Government or any agency or
instrumentality thereof having maturities of not more than six months from the
date of acquisition, (ii) time deposits, certificates of deposit and eurodollar
time deposits with maturities of not more than six months from the date of
acquisition, bankers' acceptances with maturities not exceeding six months from
the date of acquisition and overnight bank deposits, in each case with any
Lender or with any domestic commercial bank having capital and surplus in excess
of $500,000,000, (iii) repurchase obligations with a term of not more than
thirty days for underlying securities of any of the types described in clause
(i) or (ii) and entered into with any bank meeting the qualifications specified
in clause (ii) above, (iv) commercial paper maturing in 180 days or less rated
not lower than A-1 by S&P or P-1 by Moody's on the date of acquisition, and (v)
interests in pooled investment funds the assets of which are invested in
investments referred to in clauses (i) through (iv) above.

                                       3
<PAGE>
 
          Closing shall mean the execution and delivery of this Agreement and
the other Loan Documents by the parties hereto and thereto on the Closing Date.

          Closing Date shall mean February 16, 1999.

          Closing Fee shall mean a fee of twenty (20) basis points payable to
each Lender on the Closing Date based on each Lender's Revolving Credit
Commitment on the Closing Date.

          Commitment Fee shall have the meaning ascribed to it in Section 2.03
hereof.

          Compliance Certificate shall mean a certificate executed by the Chief
Executive Officer, President or the Treasurer of the Borrower, substantially in
the form of Exhibit "D" hereto.

          Consolidated Current Assets shall mean, as of any date of
determination, the Borrower's and its Subsidiaries' current assets determined
and consolidated in accordance with GAAP consistently applied.

          Consolidated Current Liabilities shall mean, as of any date of
determination, the Borrower's and its Subsidiaries' current liabilities
determined and consolidated in accordance with GAAP consistently applied.

          Consolidated EBITDA shall mean, for any period, the consolidated net
income (or net loss) of the Borrower and its Subsidiaries for such period as
determined in accordance with GAAP, plus (a) the sum of (i) depreciation
expense, (ii) amortization expense, (iii) Interest Expense, (iv) total income
tax expense, each determined in accordance with GAAP, excluding any non-
recurring or extraordinary income or losses for such period, determined in
accordance with GAAP.

          Consolidated Intangible Assets shall mean, with respect to the
Borrower and its Subsidiaries, all assets properly classified as intangible
assets under GAAP, including without limitation goodwill, patents, copyrights,
trademarks, trade names, franchises, licenses, organization costs and deferred
charges, determined and consolidated in accordance with GAAP consistently
applied.

          Consolidated Interest Expense shall mean, as of the date of
determination, the Borrower's and its Subsidiaries' interest expense, determined
and consolidated in accordance with GAAP consistently applied.

          Consolidated Net Worth shall mean, as of any date of determination,
stockholders' equity of the Borrower, determined and consolidated in accordance
with GAAP consistently applied.

          Consolidated Tangible Net Worth shall mean the remainder determined by
subtracting from Consolidated Net Worth the aggregate amount of Consolidated
Intangible Assets.

                                       4
<PAGE>
 
          Consolidated Total Indebtedness shall mean, as of any date of
determination, the Indebtedness of the Borrower and its Subsidiaries, as
determined and consolidated in a manner in accordance with GAAP consistently
applied.

          Consolidated Total Indebtedness to Consolidated EBITDA Ratio shall
mean, as of any date of determination, the ratio of the Borrower's Consolidated
Total Indebtedness as of the end of the Borrower's most recently completed
Fiscal Quarter to the Borrower's Consolidated EBITDA for the Borrower's four
most recently completed Fiscal Quarters treated as a single accounting period.

          Control shall mean the possession, directly or indirectly, of the
power to direct or cause the direction of the management or policies of a
Person, whether through the ownership of voting securities, by contract or
otherwise, including the power to elect a majority of the directors or trustees
of a corporation or trust, as the case may be, and the terms "Controlled" and
"Controlling" shall have correlative meanings.

          Current Ratio shall mean, as of any date of determination, the ratio
of the Borrower's Consolidated Current Assets to the Borrower's Consolidated
Current Liabilities.

          December 1998 Delivery Date shall mean the date on which the annual
financial statements described in Section 6.02 for the Fiscal Year ending
December 31, 1998, are delivered to the Agent.

          Default shall mean any event or condition which with notice or passage
of time or both, would constitute an Event of Default.

          Dollar, Dollars, U.S. Dollars and the symbol $ shall mean lawful money
of the United States of America.

          Environmental Complaint shall mean any written complaint setting forth
a cause of action for personal or property damage or equitable relief, or any
order, notice of violation or citation issued pursuant to any Environmental Laws
by an Official Body, subpoena or other written notice of any type relating to,
arising out of, or issued pursuant to, any Environmental Laws or any
Environmental Conditions.

          Environmental Conditions shall mean any conditions of the environment,
including, without limitation, the work place, the ocean, natural resources
(including flora or fauna), soil, surface water, ground water, any actual or
potential drinking water supply sources, substrata or the ambient air, relating
to or arising out of, or caused by the use, handling, storage, treatment,
recycling, generation, transportation, release, spilling, leaking, pumping,
emptying, discharging, injecting, escaping, leaching, disposal, dumping,
threatened release or other management or mismanagement of Regulated Substances
resulting from the use of, or operations on, any of the Property.

          Environmental Laws shall mean all federal, state; local and foreign
Laws and regulations, including permits, licenses, authorizations, bonds,
orders, judgments and consent decrees issued or entered into pursuant thereto,
relating to pollution or protection of human health or the environment or
employee safety in the work place.

                                       5
<PAGE>
 
          ERISA shall mean the Employee Retirement Income Security Act of 1974,
as the same may be amended or supplemented from time to time, and any successor
statute of similar import, and the rules and regulations thereunder, in each
case as from time to time in effect.

          ERISA Group shall mean, at any time, the Borrower and all members of a
controlled group of corporations and all trades or businesses (whether or not
incorporated) under common control and all other entities which, together with
the Borrower, are treated as a single employer under Section 414 of the Internal
Revenue Code.

          Euro-Rate shall mean for any day, as used herein, for each segment of
the Euro-Rate Portion corresponding to a proposed or existing Euro-Rate Interest
Period, the interest rate per annum determined by the Agent by dividing (the
resulting quotient rounded upward to the nearest 1/l00th of 1% per annum) (i)
the rate of interest determined by the Agent in accordance with its usual
procedures (which determination shall be conclusive absent manifest error) to be
the average of the London interbank offered rates of interest for U.S. Dollars
quoted by the British Bankers' Association as set forth on Dow Jones Markets
Service (formerly known as Telerate) display page 3750 (or if no such quotation
is available, a comparable replacement determined by the Agent two (2) Business
Days prior to the first day of such Euro-Rate Interest Period for an amount
comparable to such Euro-Rate Portion for such Euro-Rate Interest Period and
having a borrowing date and a maturity comparable to such Interest Period by
(ii) a number equal to 1.00 minus the Euro-Rate Reserve Percentage. The Euro-
Rate may also be expressed by the following formula:

                    Average of London interbank offered rates quoted by British
                    Banker's Association, as shown on Dow Jones Market
     Euro-Rate  =   Service display page 3750, or appropriate successor
                    ---------------------------------------------------
                           1.00 - Euro-Rate Reserve Percentage

The Euro-Rate shall be adjusted with respect to any Euro-Rate Option outstanding
on the effective date of any change in the Euro-Rate Reserve Percentage as of
such effective date. The Agent shall give prompt notice to the Borrower of the
Euro-Rate as determined or adjusted in accordance herewith, which determination
shall be conclusive absent manifest error.

          Euro-Rate Interest Period shall mean any individual period equal to
one (1), two (2), three (3) or six (6) months selected by the Borrower
commencing on the Borrowing Date, a conversion date or a renewal date of a Euro-
Rate Portion to which such period shall apply; provided, however, that prior to
the date which is the Business Day following the Syndication Date, only such
periods as the Agent and the Borrower mutually agree upon, not to exceed a
period of one month, shall be available.

          Euro-Rate Option shall mean the interest rate option described in
Section 2.08b(ii) hereof.

          Euro-Rate Portion shall mean each portion of the Revolving Credit
Loans which bears, or is to bear, interest under the Euro-Rate Option; and the
term Euro-Rate Portions shall mean collectively all such portions of the
Revolving Credit Loans which bear, or are to bear, interest under the Euro-Rate
Option.

                                       6
<PAGE>
 
          Euro-Rate Reserve Percentage shall mean for any day the maximum
effective percentage as determined by the Agent in accordance with its usual
procedures (which determination shall be conclusive absent manifest error) as
prescribed by the Federal Reserve Board (or any successor) for determining the
reserve requirements (including, without limitation, supplemental, marginal and
emergency reserve requirements) with respect to eurocurrency funding (currently
referred to as "Eurocurrency Liabilities") of a member bank in such System.

          Event of Default shall have the meaning ascribed to it in Section 8.01
hereof.

          Existing Letter of Credit shall mean a letter of credit outstanding on
the Closing Date issued by PNC Bank under and pursuant to the terms of the Prior
Credit Agreement or any other letter of credit issued by any Lender on behalf of
the Borrower and shown on Schedule 2.17(j).

          Expiration Date shall mean January 31, 2002.

          Federal Bankruptcy Code shall mean the bankruptcy code of the United
States of America codified in Title 11 of the United States Code, as from time
to time amended or supplemented.

          Federal Funds Effective Rate shall mean for any day the rate per annum
(based on a year of 360 days and actual days elapsed and rounded upward to the
nearest 1/100 of 1%) announced by the Federal Reserve Bank of New York (or any
successor) on such day (or if such day is not a Business Day, the previous
Business Day) as being the weighted average of the rates on overnight federal
funds transactions with members of the Federal Reserve System arranged by
federal funds brokers on the previous trading day, as computed and announced by
such Federal Reserve Bank (or any successor) in substantially the same manner as
such Federal Reserve Bank computes and announces the weighted average it refers
to as the "Federal Funds Effective Rate" as of the date of this Agreement.

          Federal Reserve Board shall mean the Board of Governors of the United
States Federal Reserve System as constituted from time to time.

          Fee shall mean any of the Commitment Fee, the Letter of Credit Fee,
the L/C Fronting Fee, the Agent's Fee, the Closing Fee any underwriting or
administration fee payable to the Agent, and any other fee payable under any of
the other Loan Documents.

          Fiscal Quarter shall mean each three month fiscal period of the
Borrower beginning respectively on each January 1, April 1, July 1 and October 1
during the term hereof and ending on the immediately succeeding March 31, June
30, September 30 and December 31.

          Fiscal Year shall mean each 12-month fiscal period of the Borrower
beginning January 1 and ending on the immediately succeeding December 31.

          GAAP shall mean, subject to the provisions of Section 1.03 hereof,
generally accepted accounting principles set forth in the opinions and
pronouncements of the Accounting Principles Board of the American Institute of
Certified Public Accountants and statements and pronouncements of the Financial
Accounting Standards Board or in such other statements by 

                                       7
<PAGE>
 
such other entity as may be recognized by a significant segment of the
accounting profession, which are applicable to the circumstances as of the date
of determination.

          Guaranty or Guarantee shall mean any obligation, direct or indirect,
by which a Person undertakes to guaranty, assume or remain liable for the
payment of another Person's obligations, including but not limited to (i)
endorsements of negotiable instruments, (ii) discounts with recourse, (iii)
agreements to pay upon a second Person's failure to pay, (iv) agreements to
maintain the capital, working capital solvency or general financial condition of
a second Person and (v) agreements for the purchase or other acquisition of
products, materials, supplies or services, if in any case payment therefor is to
be made regardless of the nondelivery of such products, materials or supplies or
the non-furnishing of such services.

          Indebtedness shall mean as to any Person at any time, any and all
indebtedness, obligations or liabilities (whether matured or unmatured,
liquidated or unliquidated, direct or indirect, absolute or contingent or joint
and several) of such Person for or in respect of: (i) borrowed money, (ii)
amounts raised under or liabilities in respect of any note purchase or
acceptance credit facility, (iii) reimbursement obligations (contingent or
otherwise) under any letter of credit, currency swap agreement, hedging
contracts, Interest Hedge Agreement or other interest rate management device,
raw materials management device or commodities management device (except raw
materials or commodity management devices entered into in the ordinary course of
business), (iv) any other transaction (including forward sale or purchase
agreements, capitalized leases and conditional sales agreements) having the
commercial effect of a borrowing of money entered into by such person to finance
its operations or capital; requirements (but not including trade payables and
accrued expenses incurred in the ordinary course of business which are not
represented by a promissory note or other evidence of indebtedness), or (v) any
Guaranty of any of the foregoing.

          Ineligible Security shall mean any security which may not be
underwritten or dealt in by member banks of the Federal Reserve System under
Section 16 of the Banking Act of 1933 (12 U.S.C. Section 24, Seventh), as
amended.

          Interest Hedge Agreement shall mean any interest rate swap agreement,
interest rate cap agreement, interest rate collar agreement, interest rate
insurance or any other agreement or arrangement designed to provide protection
against fluctuations in interest rates.

          Interest Rate Option shall mean the Euro-Rate Option or the Base Rate
Option.

          Internal Revenue Code shall mean the Internal Revenue Code of 1986, as
the same may be amended or supplemented from time to time, and any successor
statute of similar import, and the rules and regulations thereunder, as from
time to time in effect.

          L/C Fronting Fee shall have the meaning ascribed to it in Section
2.17(b) of this Agreement.

          L/C Issuer shall mean PNC Bank as the issuer of Letters of Credit
pursuant to Section 2.17, and any successor to PNC Bank as the issuer of Letters
of Credit hereunder.

          Labor Contracts shall have the meaning ascribed to it in Section 4.19
hereof.

                                       8
<PAGE>
 
          Law shall mean any law (including common law), constitution, statute,
treaty, regulation, rule, ordinance, opinion, release, ruling, order,
injunction, writ, decree or award of any Official Body.

          Lender Obligations shall mean collectively, (i) all unpaid principal
and accrued and unpaid interest under the Revolving Credit Loans and the
Swingline Loan, (ii) all accrued and unpaid Fees hereunder or under any of the
other Loan Documents, (iii) the face amount of all Letters of Credit then
outstanding, together with all Unreimbursed L/C Draws and all accrued and unpaid
interest on such Unreimbursed L/C Draws, (iv) the actual (as opposed to nominal)
credit exposure determined in accordance with standard industry practices to any
Lender or Affiliate of a Lender under an Interest Hedge Agreement between such
Person and the Borrower, (v) any other amounts payable hereunder or under any of
the other Loan Documents, including all reimbursements, indemnities, fees,
costs, expenses, prepayment premiums and other obligations of the Borrower to a
Lender (in any capacity hereunder), the L/C Issuer or the Swingline Lender or
any indemnified party hereunder, (vi) all out-of-pocket costs and expenses
incurred by the Agent in connection with this Agreement or any other Loan
Documents, including but not limited to the reasonable fees and expenses of the
Agent's counsel, (vii) all out-of-pocket costs and expenses incurred by a
Lender, the L/C Issuer or the Swingline Lender after an Event of Default in
connection with any administration or enforcement of the Loan Documents,
including but not limited to the reasonable fees and expenses of such Lender's,
L/C Issuer's or Swingline Lender's counsel, and (viii) all other liabilities,
obligations, covenants, duties and Indebtedness of the Borrower to the Agent,
the L/C Issuer, the Swingline Lender and the Lenders of any and every kind and
nature, arising under this Agreement or the other Loan Documents, whether
heretofore, now or hereafter owing, arising, due or payable from the Borrower to
the Agent, the L/C Issuer, the Swingline Lender or the Lenders.

          Lenders shall mean the financial institutions named on Schedule
1.01(a) hereto and their respective successors and assigns as permitted
hereunder, each of which is referred to herein as a Lender.

          Letter of Credit shall mean any standby letter of credit issued by the
L/C Issuer for the account of the Borrower upon the application of the Borrower
pursuant to this Agreement and any Existing Letter of Credit, and all
extensions, renewals, amendments, substitutions and replacements thereto and
thereof.

          Letter of Credit Fee shall have the meaning ascribed to it in Section
2.17(b).

          Lien shall mean any mortgage, deed of trust, pledge, lien, security
interest, charge or other encumbrance or security arrangement of any nature
whatsoever, whether voluntarily or involuntarily given, including but not
limited to any conditional sale or title retention arrangement, and any
assignment, deposit arrangement or lease intended as, or having the effect of,
security and any filed financing statement or other notice of any of the
foregoing (whether or not a lien or other encumbrance is created or exists at
the time of the filing).

          Loans shall mean Revolving Credit Loans and Swingline Loans and the
term Loan shall mean separately any Revolving Credit Loan or Swingline Loan.

          Loan Account shall mean the loan account maintained by the Agent as
more fully described in Section 2.14 hereof.

                                       9
<PAGE>
 
          Loan Disbursement Account shall have the meaning ascribed to it in
Section 3.01 hereof.

          Loan Documents shall mean this Agreement, the Notes, any Application
for Letter of Credit, the Subsidiary Guarantees, any Interest Rate Hedge
Agreement executed by a Lender or an affiliate of a Lender, and any other
agreements, instruments, certificates or documents contemplated thereby, as any
of the same may be supplemented or amended from time to time in accordance
herewith or therewith; and the term Loan Document shall mean any of the Loan
Documents.

          Loan Parties shall mean the Borrower and the Subsidiary Guarantors and
the term Loan Party shall mean any of the Loan Parties.

          Loan Request shall mean a request for Revolving Credit Loans made in
accordance with Section 2.05 hereof which request shall be substantially in the
form of Exhibit "B" hereto.

          Margin Regulations shall mean Regulation T, U and X as promulgated by
the Board of Governors of the Federal Reserve System, as amended from time to
time.

          Material Adverse Change shall mean any set of circumstances or events
which (a) has or could reasonably be expected to have any material adverse
effect upon the validity or enforceability of this Agreement or any of the other
Loan Documents, (b) is or could reasonably be expected to be material and
adverse to the business, properties, assets, financial condition or results of
operations of the Borrower and its Subsidiaries, taken as a whole, (c) impairs
materially or could reasonably be expected to impair materially the ability of
the Borrower and its Subsidiaries taken as a whole to duly and punctually pay
their Indebtedness, or (d) impairs materially or could reasonably be expected to
impair materially the ability of the Agent, any of the Lenders, the L/C Issuer
or the Swingline Lender to enforce their legal remedies pursuant to this
Agreement or any other Loan Document.

          Moody's shall mean Moody's Investors Service, Inc., a corporation
organized and existing under the laws of the State of Delaware, its successors
and assigns, and, if such corporation shall be dissolved or liquidated or shall
no longer perform the functions of a securities rating agency, "Moody's" shall
be deemed to refer to any other nationally recognized securities rating agency
designated by the Agent, with the approval of the Borrower, by notice to the
Lenders, the L/C Issuer and the Swingline Lender.

          Multiemployer Plan shall mean any employee benefit plan which is a
"multiemployer plan" within the meaning of Section 4001(a)(3) of ERISA and to
which the Borrower or any member of the ERISA Group is then making or accruing
an obligation to make contributions or, within the preceding five Plan years,
has made or had an obligation to make such contributions.

          Multiple Employer Plan shall mean a Plan which has two or more
contributing sponsors (including the Borrower or any member of the ERISA Group)
at least two of whom are not under common control, as such a plan is described
in Sections 4063 and 4064 of ERISA.

          Notes shall mean collectively all of the Revolving Credit Notes and
the Swingline Note and the term Note separately shall mean any Revolving Credit
Note or the Swingline Note.

                                       10
<PAGE>
 
          Official Body shall mean any national, federal, state, local or other
government or political subdivision or any agency, authority, bureau, central
bank, commission, department or instrumentality of either, or any court,
tribunal, grand jury or arbitrator, in each case whether foreign or domestic.

          Other Taxes shall have the meaning assigned to it in Section 2.18(b).

          Participant shall mean any bank or financial institution which
acquires from any Lender an undivided interest in such Lender's Ratable Share
of the Revolving Credit Commitments, Revolving Credit Loans, Letters of Credit
and Unreimbursed L/C Draws, pursuant to Section 10.05.

          Participation shall mean the sale, made in accordance with the
provisions of Section 10.05, by any Lender to any Participant of an undivided
interest in such Lender's Ratable Share of the Revolving Credit Commitments,
Revolving Credit Loans, Letters of Credit and Unreimbursed L/C Draws.

          PBGC shall mean the Pension Benefit Guaranty Corporation established
pursuant to Subtitle A of Title IV of ERISA or any successor.

          Permitted Liens shall mean:

                (i) Liens for taxes, assessments, governmental levies or similar
     charges incurred in the ordinary course of business and which are not yet
     due and payable, or if due and payable, (aa) are being contested in good
     faith and by appropriate and lawful proceedings diligently conducted, but
     only so long as such proceedings could not subject the Agent, the Lenders,
     the L/C Issuer or the Swingline Lender to any civil or criminal penalties
     or liabilities and (bb) for which such reserves or other appropriate
     provisions, if any, as shall be required by GAAP shall have been made and
     (cc) which shall be paid in accordance with the terms of any final
     judgments or orders relating thereto within thirty (30) days after the
     entry of such judgments or orders;

                (ii) Pledges or deposits made in the ordinary course of business
     to secure payment of workmen's compensation, or to participate in any fund
     in connection with workmen's compensation, unemployment insurance, old-age
     pensions, other social security programs or similar program or to secure
     liability to insurance carriers under insurance or self insurance
     agreements or arrangement;

                (iii) Liens of mechanics, materialmen, warehousemen, carriers,
     or other like Liens, securing obligations incurred in the ordinary course
     of business that are not yet due and payable and Liens of landlords
     securing obligations to pay lease payments that are not yet due and payable
     or in default, or if such Liens are due and payable, (aa) are being
     contested in good faith and by appropriate and lawful proceedings
     diligently conducted and (bb) for which such reserves or other appropriate
     provisions, if any, as required by GAAP shall have been made and (cc) which
     shall be paid in accordance with the terms of any final judgments or orders
     relating thereto within thirty (30) days after the entry of such judgments
     or orders;

                (iv) Pledges or deposits made in the ordinary course of business
     to secure performance of bids, tenders, contracts (other than for the
     repayment of borrowed money) or 

                                       11
<PAGE>
 
     leases, not in excess of the aggregate amounts due thereunder, or to secure
     statutory obligations, or surety, appeal, indemnity, performance or other
     similar bonds required in the ordinary course of business;

                (v) (aa) Encumbrances consisting of zoning restrictions,
     easements, rights-of-way, or other restrictions on the use of real
     property, (bb) defects in title to real property, and (cc) Liens,
     encumbrances and title defects affecting real property not known by the
     Borrower or a Subsidiary, as applicable, and not discoverable by a search
     of the public records, none of which materially impairs the use of such
     property;

                (vi) (aa) Liens on assets of a Person which is merged into or
     acquired by the Borrower or a Subsidiary of the Borrower on or after the
     date of this Agreement, and (bb) Liens on assets acquired after the date of
     this Agreement, provided that (A) such Liens existed at the time of such
     merger or acquisition and were not created in anticipation thereof, (B) no
     such Lien is spread to cover any property or assets of the Borrower or any
     Subsidiary of the Borrower; and (C) the principal amount of Indebtedness
     secured thereby is not increased from the amount outstanding immediately
     prior to such merger or acquisition;

                (vii) Liens created by or resulting from any litigation or legal
     proceedings which are currently being contested in good faith by
     appropriate and lawful proceedings diligently conducted and for which such
     reserves or other appropriate provisions, if any, as shall be required by
     GAAP shall have been made and Liens arising out of judgments or orders for
     the payment of money which do not constitute an Event of Default hereunder;

                (viii) Liens placed upon fixed assets or equipment hereafter
     acquired to secure all or a portion of the purchase price thereof, provided
     that any such Lien shall not encumber any other property of the Borrower or
     any Subsidiary;

                (ix) Other Liens incidental to the conduct of the Borrower's or
     any Subsidiary's business or the ownership of its property and assets which
     were not incurred in connection with the borrowing of money or the
     obtaining of advances or credit, and which do not in the aggregate
     materially detract from the value of the Borrower's or any Subsidiary's
     property or assets or which do not materially impair the use thereof in the
     operation of the Borrower's business; and

                (x) Leases or subleases not otherwise prohibited by this
     Agreement or other Loan Documents; provided, however, except as set forth
     in items (i) through (x) of this definition the Borrower shall not permit
     or authorize Liens on any of the Borrower's or any of its Subsidiaries'
     properties, except in favor of the Agent for the benefit of the Agent, the
     Lenders, the L/C Issuer and the Swingline Lender.

     Person or person shall mean any individual, corporation, partnership,
limited liability company, association, joint-stock company, trust,
unincorporated organization, joint venture, government or political subdivision
or agency thereof, or any other entity.

     Plan shall mean at any time an employee pension benefit plan (including a
Multiple Employer Plan but not a Multiemployer Plan) which is covered by Title
IV of ERISA or is subject to the minimum funding standards under Section 412 of
the Internal Revenue Code and either (i) is maintained by any member of the
ERISA Group for employees of any member of the ERISA Group or (ii) has at any
time within the preceding five years been maintained by 

                                       12
<PAGE>
 
any entity which was at such time a member of the ERISA Group for employees of
any entity which was at such time a member of the ERISA Group.

     PNC Bank shall mean PNC Bank, National Association, and its successors and
assigns.

     Portions shall mean collectively the Base Rate Portions and the Euro-Rate
Portions; and the term Portion shall mean individually any of the Portions.

     Prime Rate shall mean for any day, a fluctuating interest rate per annum
equal to the rate of interest which the Agent announces from time to time as its
prime lending rate, which rate may not be the lowest rate then being charged by
the Agent to commercial borrowers.

     Principal Office shall mean the principal commercial banking office of the
Agent in Pittsburgh, Pennsylvania.

     Prior Credit Agreement shall mean the Amended and Restated Credit Agreement
dated as of June 30, 1992, by and among the Borrower, the banks party thereto as
lenders, and PNC Bank as agent and letter of credit issuer, as the same has been
amended from time to time.

     Prohibited Transaction shall mean any prohibited transaction as defined in
Section 4975 of the Internal Revenue Code or Section 406 of ERISA for which
neither an individual nor a class exemption has been issued by the United States
Department of Labor.

     Property shall mean, and refer to, each parcel of real property, whether
owned in fee or leased, of any Loan Party.

     Purchasing Lender shall mean a Lender which becomes a party to this
Agreement by executing an Assignment and Assumption Agreement.

     Ratable Share shall mean the proportion that a Lender's Revolving Credit
Commitment bears to the Revolving Credit Commitments of all of the Lenders.

     Register shall have the meaning ascribed to it in Section 10.05(c).

     Regulated Substances shall mean any substance, including without limitation
Solid Waste, the generation, manufacture, processing, distribution, treatment,
storage, disposal, transport, recycling, reclamation, use, reuse or other
management or mismanagement of which is regulated by the Environmental Laws.

     Reportable Event shall mean a reportable event described in Section 4043 of
ERISA and regulations thereunder with respect to a Plan or Multiemployer Plan.

     Required Lenders shall mean Lenders whose Revolving Credit Commitments
aggregate at least 51% of the Revolving Credit Commitments of all of the
Lenders.

     Revolving Credit Commitment shall mean, as to any Lender at any time,
the amount initially set forth opposite its name on Schedule 1.01(a) in the
column labeled "Amount 

                                       13
<PAGE>
 
of Commitment for Revolving Credit Loans, and thereafter on Schedule I to the
most recent Assignment and Assumption Agreement, as the same may be reduced
pursuant to Sections 2.04 or 2.l0(a) hereof, and Revolving Credit Commitments
shall mean the aggregate Revolving Credit Commitments of all of the Lenders.

     Revolving Credit Loans shall mean collectively, all Revolving Credit Loans
and Revolving Credit Loan shall mean any Revolving Credit Loan made by the
Lenders or one of the Lenders to the Borrower pursuant to Section 2.01 hereof.

     Revolving Credit Notes shall mean collectively all the promissory notes of
the Borrower in the form of Exhibit "A-1" hereto and Revolving Credit Note shall
mean separately each promissory note of the Borrower substantially in the form
of Exhibit "A-1" hereto in each case evidencing the Revolving Credit Loans
together with all amendments, extensions, renewals, replacements, refinancings
or refundings thereof or thereto in whole or in part.

     S&P shall mean Standard & Poor's Ratings Group, a division of McGraw Hill
Corporation, and, if such corporation shall be dissolved or liquidated or shall
no longer perform the functions of a securities rating agency, "S&P" shall be
deemed to refer to any other nationally recognized securities rating agency
designated by the Agent, with the approval of the Borrower, by notice to the
Lenders, the L/C Issuer and the Swingline Lender.

     Section 20 Subsidiary shall mean a Subsidiary of the bank holding company
controlling any Lender, the L/C Issuer or the Swingline Lender, which Subsidiary
has been granted authority by the Federal Reserve Board to underwrite and deal
in certain Ineligible Securities.

     Solid Waste shall mean any garbage, refuse or sludge from any waste
treatment plant, water supply treatment plant or air pollution control facility
generated by activities on the Property, and any unpermitted release into the
environment or the work place of any material as a result of activities on the
Property, including without limitation used Regulated Substances.

     Solvent shall mean, with respect to any person on a particular date, that
on such date (i) the fair value of the property of such person is greater than
the total amount of liabilities, including, without limitation, contingent
liabilities, of such person, (ii) the present fair salable value of the assets
of such person is not less than the amount that will be required to pay the
probable liability of such person on its debts as they become absolute and
matured, (iii) such person is able to realize upon its assets and pay its debts
and other liabilities, contingent obligations and other commitments as they
mature in the normal course of business, (iv) such person does not intend to,
and does not believe that it will, incur debts or liabilities beyond such
person's ability to pay as such debts and liabilities mature, and (v) such
person is not engaged in business or a transaction, and is not about to engage
in business or a transaction, for which such person's property would constitute
unreasonably small capital after giving due consideration to the prevailing
practice in the industry in which such person is engaged. In computing the
amount of contingent liabilities at any time, it is intended that such
liabilities will be computed at the amount which, in light of all the facts and
circumstances existing at such time, represents the amount that can reasonably.
be expected to become an actual or matured liability.

                                       14
<PAGE>
 
     Stated Amount shall mean as to any Letter of Credit, the lesser of (i) the
face amount thereof or (ii) the remaining available undrawn amount thereof
(regardless of whether any conditions for drawing could then be met).

     Subsidiary of any Person at any time shall mean (i) any corporation or
trust of which 50% or more (by number of shares or number of votes) of the
outstanding capital stock or shares of beneficial interest normally entitled to
vote for the election of one or more directors or trustees (regardless of any
contingency which does or may suspend or dilute the voting rights) is at such
time owned directly or indirectly by such Person or one or more of such Person's
Subsidiaries, (ii) any partnership of which such Person is a general partner or
of which 50% or more of the partnership interests is at the time directly or
indirectly owned by such Person or one or more of such Person's Subsidiaries,
(iii) any limited liability company of which such Person is a member or of which
50% or more of the limited liability company interests is at the time directly
or indirectly owned by such Person or one or more of such Person's Subsidiaries
or (iv) any corporation, trust, partnership, limited liability company or other
entity which is Controlled or capable of being Controlled by such Person or one
or more of such Person's Subsidiaries.

     Subsidiary Guarantors shall mean each Subsidiary of the Borrower listed on
Schedule 3.02 attached hereto together with each Subsidiary of the Borrower
incorporated or organized in the United States of America, acquired,
incorporated or formed after the date hereof, except as released by the Lenders
pursuant to Section 3.02 hereof.

     Subsidiary Guaranty shall mean a guaranty agreement executed by a
Subsidiary Guarantor substantially in the form of Exhibit "C" attached hereto,
together in each case with all extensions, renewals, amendments, substitutions
and replacements thereto and thereof.

     Swingline Lender shall mean PNC Bank as the provider of the Swingline
Option pursuant to Section 2.13, and any successor to PNC Bank as the provider
of the Swingline Option hereunder.

     Swingline Loan shall mean a disbursement made by the Swingline Lender to
the Borrower pursuant to Section 2.13.

     Swingline Note shall mean the promissory note of the Borrower evidencing
Indebtedness of the Borrower under the Swingline Loan which note is
substantially in the form of Exhibit "A-2" attached hereto, together with all
extensions, renewals, amendments, modifications, substitutions and replacements
thereto and thereof.

     Swingline Option shall mean the loan option between the Borrower and the
Swingline Lender pursuant to Section 2.13 hereof.

     Syndication Date shall mean the earlier of (i) the date of completion of
syndication hereunder, as determined by the Agent, or (ii) ninety (90) days
after the Closing Date.

     Taxes shall have the meaning ascribed to it in Section 2.18.

     Termination Event: (i) A Reportable Event with respect to a Plan or an
event described in Section 4062(e) of ERISA with respect to a Plan, (ii) the
withdrawal of the 

                                       15
<PAGE>
 
Borrower or any ERISA Affiliate from a Plan during a Plan year in which the
Borrower or such ERISA Affiliate was a "substantial employer", as such term is
defined in Section 4001(a)(2) of ERISA, (iii) the incurrence of liability by the
Borrower or such ERISA Affiliate under Section 4064 of ERISA upon the
termination of a Plan, (iv) the distribution of a notice of intent to terminate
a Plan pursuant to Section 4041(c) of ERISA or the treatment of a Plan amendment
as a termination under Section 4041 of ERISA, (v) the institution of proceedings
to terminate a Plan by the PBGC under Section 4042 of ERISA, or (vi) any other
event or condition which might reasonably constitute grounds under Section 4042
of ERISA for the termination of, or the appointment of a trustee to administer,
any Plan.

     Total Utilization shall mean as of the time of determination the sum of
Revolving Credit Loans outstanding, Swingline Loans outstanding, the
Unreimbursed L/C Draws outstanding and the aggregate Stated Amount of the
Letters of Credit outstanding.

     Transfer Effective Date shall have the meaning ascribed to it in the
applicable Assignment and Assumption Agreement.

     Transferor Lender shall mean the selling Lender pursuant to an Assignment
and Assumption Agreement.

     Uniform Commercial Code or UCC shall mean the Pennsylvania Uniform
Commercial Code.

     Unreimbursed L/C Draw shall have the meaning ascribed to it in Section
2.17(f).

     Year 2000 Problem shall have the meaning ascribed to it in Section 4.27.

     1.02. Construction.

     (a) Unless the context of this Agreement otherwise clearly requires, the
following rules of construction shall apply to this Agreement and each of the
other Loan Documents:

         (i) Number: Inclusion. References to the plural include the singular,
     the singular the plural and the part the whole, "or" has the inclusive
     meaning represented by the phrase "and/or," and "including" has the meaning
     represented by the phrase "including without limitation".

         (ii) Determination. References to "determination" of or by the Agent,
     the L/C Issuer, the Swingline Lender or the Lenders shall be deemed to
     include good faith estimates by the Agent, the L/C Issuer, the Swingline
     Lender or the Lenders (in the case of quantitative determinations) and good
     faith beliefs by the Agent, the L/C Issuer, the Swingline Lender or the
     Lenders (in the case of qualitative determinations) and such determination
     shall be conclusive absent manifest error.

         (iii) Discretion and Consent. Whenever the Agent, the L/C Issuer, the
     Swingline Lender or the Lenders are granted the right herein to act in its
     or their sole discretion or to grant or withhold consent such right shall
     be exercised in good faith.

                                       16
<PAGE>
 
         (iv) Documents Taken as a Whole. The words "hereof," "herein,"
     "hereunder", "hereto" and similar terms in this Agreement or any other Loan
     Document refer to this Agreement or such other Loan Document as a whole and
     not to any particular provision of this Agreement or such other Loan
     Document.

         (v) Headings. The article, section and other headings contained in this
     Agreement or such other Loan Documents and the Table of Contents preceding
     this Agreement or such other Loan Document are for reference purposes only
     and shall not control or affect the construction of this Agreement or such
     other Loan Document or the interpretation thereof in any respect.

         (vi) Implied References. Article, section, subsection, item, clause,
     schedule and exhibit references are to this Agreement or to such other Loan
     Document, as the case may be, unless otherwise specified.

         (vii) Persons. Reference to any Person includes such Person's
     successors and assigns, but, if applicable, only if such successors and
     assigns are permitted by this Agreement or such other Loan Document, as the
     case may be, and reference to a Person in a particular capacity excludes
     such Person in any other capacity.

         (viii) Laws and Agreements. Reference to any Law, agreement or contract
     includes such Law, agreement or contract as the same may be amended,
     supplemented, modified, extended, waived, consolidated, replaced or renewed
     from time to time, but only to the extent permitted by, and effected in
     accordance with, the terms thereof and of this Agreement and the other Loan
     Documents.

         (ix) From, To and Through. Relative to the determination of any period
     of time, "from" means "from and including", "to" means "to but excluding",
     and "through" means "through and including".

         (x) Shall; Will. References to "shall" and "will" are intended to have
     the same meaning.

         (xi) UCC Terms. All terms used in Article 9 of the UCC and not
     specifically defined in this Agreement or in any other Loan Document shall
     herein have the meanings assigned to such terms in the UCC as from time to
     time in effect in the Commonwealth of Pennsylvania.

         (xii) Writing; Written. References to "writing" include printing,
     typing, lithography and other means of reproducing words in a tangible
     visible form. References to "written" include "printed", "typed",
     "lithographed" and other adjectives relating to words reproduced in a
     tangible visible form consistent with the preceding sentence and also
     include electronic images and images stored on computer disks, magnetic
     tape and like media.

     1.03. Accounting Principles. Except as otherwise provided in this
Agreement, all computations and determinations as to accounting or financial
matters and all financial statements to be delivered pursuant to this Agreement
shall be made and prepared in accordance with GAAP (including principles of
consolidation where appropriate), and all accounting or financial terms shall
have the meanings ascribed to such terms by GAAP.

                                       17
<PAGE>
 
                                   ARTICLE II
                           REVOLVING CREDIT FACILITY

     2.01. Revolving Credit Commitments. Subject to the terms and conditions
hereof and relying upon the representations and warranties herein set forth,
each Lender severally agrees to make revolving credit loans (the "REVOLVING
CREDIT LOANS") to the Borrower at any time or from time to time on or after the
date hereof to, but not including, the Expiration Date, provided that the
aggregate principal amount of each Lender's Revolving Credit Loans outstanding
hereunder to the Borrower shall not exceed at any one time such Lender's Ratable
Share of the aggregate Revolving Credit Commitments minus such Lender's Ratable
Share of the sum of (i) the Swingline Loans outstanding, (ii) the aggregate
Stated Amount of outstanding Letters of Credit and (iii) the aggregate amount of
Unreimbursed L/C Draws. Within such limits of time and amount and subject to the
other provisions of this Agreement, the Borrower may borrow, repay and reborrow
pursuant to this Section 2.01. The aggregate amount of the Revolving Credit
Commitments on the Closing Date is $70,000,000. All Revolving Credit Commitments
shall expire on the Expiration Date; and all Revolving Credit Loans outstanding
on the Expiration Date shall become due and payable in full on such date.

     2.02. Nature of Lenders' Obligations with Respect to Revolving Credit
Loans. Each Lender shall be obligated to participate in each request for
Revolving Credit Loans pursuant to Section 2.05 hereof in accordance with its
Ratable Share. The aggregate principal amount of each Lender's Revolving Credit
Loans outstanding hereunder to the Borrower at any time shall never exceed such
Lender's Ratable Share of the aggregate Revolving Credit Commitments, minus such
Lender's Ratable Share of the sum of (i) Swingline Loans outstanding, (ii) the
aggregate Stated Amount of outstanding Letters of Credit and (iii) the aggregate
amount of Unreimbursed L/C Draws. The obligations of each Lender hereunder are
several. The failure of any Lender to perform its obligations hereunder shall
not affect the obligations of the Borrower, or any other Lender, to any other
party nor shall the Borrower, or any other Lender, be liable for the failure of
such Lender to perform its obligations hereunder. The Lenders shall have no
obligation to make Revolving Credit Loans hereunder on or after the Expiration
Date.

     2.03. Commitment Fees

           (a) Commitment Fee. Accruing from the Closing Date until the
     Expiration Date, the Borrower agrees to pay to the Agent for the account of
     each Lender, as consideration for such Lender's Revolving Credit Commitment
     hereunder, a commitment fee (the "COMMITMENT FEE") equal to the Applicable
     Commitment Fee per annum, as determined below, (all computed on the basis
     of a year of 365 or 366 days, as the case may be, and actual days elapsed)
     on the average daily amount equal to such Lender's Revolving Credit
     Commitment minus such Lender's Ratable Share of Total Utilization relating
     to its Revolving Credit Commitment. For the purposes of calculating the
     Commitment Fee, the amount outstanding under the Swingline Loans shall not
     be included in calculating any Lender's Ratable Share of Total Utilization
     relating to its Revolving Credit Commitment.

           (b) Applicable Commitment Fee. For purposes of this Agreement, the
     term "APPLICABLE COMMITMENT FEE" shall mean the rate per annum set forth in
     the chart below which corresponds to the range of ratios in which the
     Borrower's Consolidated Total Indebtedness to Consolidated EBITDA Ratio, as
     at the end of the preceding fiscal quarter, falls:

                                       18
<PAGE>
 
<TABLE>
<CAPTION>
----------------------------------------------------------------------------------  
              Consolidated Total Indebtedness                     Applicable
                to Consolidated EBITDA Ratio                     Commitment Fee
---------------------------------------------------------------------------------- 
<S>                                                            <C>  
Less than or equal to 1.0 to 1.0                                       .20%
----------------------------------------------------------------------------------
Greater than 1.0 to 1.0 but less than or equal to 1.5 to 1.0          .225%
---------------------------------------------------------------------------------- 
Greater than 1.5 to 1.0 but less than or equal to 2.0 to 1.0           .25%
---------------------------------------------------------------------------------- 
Greater than 2.0 to 1.0 but less than or equal to 2.5 to 1.0          .275%
---------------------------------------------------------------------------------- 
Greater than 2.5 to 1.0                                                .30%
---------------------------------------------------------------------------------- 
</TABLE>

All such adjustments shall be determined as of the date the Borrower's financial
statements and Compliance Certificate are required to be delivered to the Agent
pursuant to items (i), (ii) and (iii) of Section 6.02. The foregoing
notwithstanding, the Applicable Commitment Fee from the Closing Date to and
including the December 1998 Delivery Date shall be .225%. All Commitment Fees
shall be payable (i) quarterly in arrears beginning March 31, 1999, and
continuing on the last Business Day of each Fiscal Quarter occurring during the
term of the Revolving Credit Commitment, (ii) upon the Expiration Date and (iii)
upon acceleration of the Notes.

     2.04. Voluntary Reduction of Revolving Credit Commitments. Subject to the
provisions of Section 2.09 hereof, at any time and from time to time upon at
least five (5) Business Days' prior written notice to the Agent, the Borrower
may terminate, in whole or in part, without penalty, the then unused portion of
the Revolving Credit Commitments, thereby causing a corresponding abatement of
the Commitment Fee. Each such reduction shall be in a minimum principal amount
of $5,000,000 or, if in excess of $5,000,000, in integral multiples of
$1,000,000. The Commitment Fee shall cease to accrue with respect to any unused
portion of the Revolving Credit Commitments so terminated five (5) Business Days
after receipt of such notice. Notice of termination once given shall be
irrevocable and the portion of the Revolving Credit Commitments so terminated
shall not be available for borrowing once such notice has been given under the
terms hereof. The Agent shall promptly notify each Lender of its Ratable Share
of such terminated unused portion and the date of each such termination.

     2.05. Revolving Credit Loan Requests. Except as otherwise provided herein,
the Borrower may from time to time prior to the Expiration Date request the
Lenders to make Revolving Credit Loans to the Borrower by the delivery to the
Agent, not later than noon (Pittsburgh, Pennsylvania time) (i) three (3)
Business Days prior to the proposed Borrowing Date with respect to the making of
Revolving Credit Loans to which the Euro-Rate Option applies; and (ii) on the
Business Day of the proposed Borrowing Date with respect to the making of a
Revolving Credit Loan to which the Base Rate Option applies, of a duly completed
request therefor substantially in the form of Exhibit "B" hereto or a request by
telephone immediately confirmed in writing by letter or facsimile in such form
(each, a "LOAN REQUEST"), it being understood that the Agent may rely on the
authority of any person making such a telephonic request without the necessity
of receipt of such written confirmation. Each Loan Request shall be irrevocable
and shall specify (i) the proposed Borrowing Date; (ii) the aggregate amount of
the proposed Revolving Credit Loans to be made on such Borrowing Date, which
amount, as to Base Rate Portions, shall be in integral multiples of $500,000 and
not less than $1,000,000 and, as to Euro-Rate Portions, shall be in integral
multiples of $1,000,000 and not less than $5,000,000; (iii) subject to Section
2.08(d), whether the Euro-Rate 

                                       19
<PAGE>
 
Option or the Base Rate Option shall apply to the proposed Revolving Credit
Loans to be made on such Borrowing Date; and (iv) in the case of Revolving
Credit Loans to which the Euro-Rate Option applies and subject to Sections
2.08(d) and 2.08(e), an appropriate Euro-Rate Interest Period for each Euro-Rate
Portion of the Revolving Credit Loans to be made on such Borrowing Date.

     2.06. Making Revolving Credit Loans. Subject to Section 9.03, the Agent
shall, promptly after receipt by it of a Loan Request pursuant to Section 2.05
(but not later than 2:00 p.m. (Pittsburgh, Pennsylvania time) on the Borrowing
Date for same day funding and 2:00 p.m. (Pittsburgh, Pennsylvania time) on the
second Business Day preceding any Borrowing Date for which any Portion of the
Revolving Credit Loans to be made on such Borrowing Date bears interest at the
Euro-Rate Option), notify the Lenders of its receipt of such Loan Request
specifying: (i) the proposed Borrowing Date and the time and method of
disbursement of such Revolving Credit Loan; (ii) the amount and type of such
Revolving Credit Loan and the applicable Euro-Rate Portions and Euro-Rate
Interest Periods (if any); and (iii) the apportionment among the Lenders of the
Revolving Credit Loans as determined by the Agent in accordance with Section
2.02 hereof. Subject to Section 9.03, each Lender shall remit the principal
amount of each Revolving Credit Loan to the Agent such that the Agent is able
to, and the Agent shall, to the extent the Lenders have made funds available to
it for such purpose, fund such Revolving Credit Loan to the Borrower in Dollars
and immediately available funds at the Principal Office prior to 2:00 P.M.
(Pittsburgh, Pennsylvania time) on the Borrowing Date, provided that if any
Lender fails to remit such funds to the Agent in a timely manner, or any Lender
fails to advise the Agent of its intention not to fund, then the Agent may elect
in its sole discretion to fund with its own funds the Revolving Credit Loan of
such Lender on the Borrowing Date.

     2.07. Revolving Credit Notes. The obligation of the Borrower to repay the
aggregate unpaid principal amount of the Revolving Credit Loans made to the
Borrower by each Lender, together with interest thereon, shall be evidenced by a
promissory note of the Borrower dated the Closing Date in substantially the form
attached hereto as Exhibit "A-1" payable to the order of each Lender in a face
amount equal to the Revolving Credit Commitment of such Lender.

     2.08. Interest Payments, Interest Rates and Certain Related Payments
Pertaining to the Revolving Credit Loans.

           (a) Interest. The Revolving Credit Notes shall bear interest on the
actual unpaid principal amount thereof from time to time outstanding from the
date thereof until payment in full at the rates of interest set forth in Section
2.08(b). The Borrower shall pay accrued interest on the unpaid principal balance
of the Revolving Credit Notes in arrears:

               (i) with respect to the Base Rate Portion, at the rate specified
in the Base Rate Option, (A) on the last Business Day of each Fiscal Quarter
during the term of the Revolving Credit Commitment, (B) at maturity, whether by
acceleration or otherwise, of the Revolving Credit Notes and (C) thereafter on
demand until all amounts evidenced by the Revolving Credit Notes are paid in
full whether or not judgment has been entered on the Revolving Credit Notes; and

               (ii) with respect to each Euro-Rate Portion, at the rate
specified in the Euro-Rate Option, (A) on the last day of the Euro-Rate Interest
Period
                                       20
<PAGE>
 
applicable thereto; provided, however, if the Euro-Rate Interest Period chosen
for any Euro-Rate Portion exceeds three (3) months, interest on that Euro-Rate
Portion shall be due and payable at the end of every three (3) months during
such Euro-Rate Interest Period and on the last day of such Euro-Rate Interest
Period, (B) at the maturity, whether by acceleration or otherwise, of the
Revolving Credit Notes and (C) thereafter on demand until all amounts evidenced
by the Revolving Credit Notes are paid in full whether or not judgment has been
entered on the Revolving Credit Notes.

           (b) Interest Rate Options. During the term hereof, the Borrower shall
have the option of electing, from time to time, one or more of the Interest Rate
Options set forth below to be applied to the Revolving Credit Loans.

               (i) Base Rate Option. Interest under this Interest Rate Option
shall accrue, for the Base Rate Portion of the Revolving Credit Loans
outstanding, at a rate per annum equal to the sum of (A) the Base Rate plus (B)
the Applicable Base Rate Margin. The Base Rate shall be adjusted automatically
from time to time upon each change in the Prime Rate or the Federal Funds
Effective Rate, as the case may be, and in accordance with the provisions of
Sections 2.08(b)(iii) and 2.08(c).

               (ii) Euro-Rate Option. Interest under this Interest Rate Option
shall accrue, for each Euro-Rate Portion of the Revolving Credit Loans
outstanding, for any Euro-Rate Interest Period selected, at a rate per annum
equal to the sum of (A) the Euro-Rate plus (B) the Applicable Euro-Rate Margin
as determined below. The rate of interest established pursuant to the preceding
sentence of this Section 2.08(b)(ii) for each Euro-Rate Portion shall be
adjusted from time to time in accordance with the provisions of Sections
2.08(b)(iii) and 2.08(c).

               (iii) Applicable Margins. For purposes of this Agreement, the
terms "APPLICABLE BASE RATE MARGIN" and "APPLICABLE EURO-RATE MARGIN" shall mean
the rate per annum set forth in the chart below under the relevant heading which
corresponds to the range of ratios in which the Borrower's Consolidated Total
Indebtedness to Consolidated EBITDA Ratio as at the end of the preceding Fiscal
Quarter falls:

<TABLE>
<CAPTION>
          Consolidated Total Indebtedness                                Applicable Base    Applicable Euro-Rate
            to Consolidated EBITDA Ratio                                   Rate Margin             Margin
----------------------------------------------------------------------------------------------------------------
<S>                                                                     <C>                 <C>
Less than or equal to 1.0 to 1.0                                                 0%                    .75%
----------------------------------------------------------------------------------------------------------------
Greater than 1.0 to 1.0 but less than or equal to 1.5 to 1.0                     0%                   1.00%
----------------------------------------------------------------------------------------------------------------
Greater than 1.5 to 1.0 but less than or equal to 2.0 to 1.0                     0%                   1.25%    
----------------------------------------------------------------------------------------------------------------
Greater than 2.0 to 1.0 but less than or equal to 2.5 to 1.0                     0%                   1.50% 
----------------------------------------------------------------------------------------------------------------
Greater than 2.5 to 1.0                                                        .25%                   1.75%
----------------------------------------------------------------------------------------------------------------
</TABLE>

All adjustments shall be determined as of the date the Borrower's financial
statements and Compliance Certificate are required to be delivered pursuant to
items (i), (ii) and (iii) of Section 6.02.  The foregoing notwithstanding, the
Applicable Base Rate Margin from the Closing Date to 

                                       21
<PAGE>
 
and including the December 1998 Delivery Date shall be .0%. The Applicable Euro-
Rate Margin from the Closing Date to and including the December 1998 Delivery
Date shall be 1.00%.

           (c) Interest After Maturity. After the occurrence of an Event of
Default and during the continuation thereof, the Base Rate Portion shall bear
interest at a rate per annum which shall be two hundred (200) basis points (2%)
above the sum of (A) the Base Rate and (B) the Applicable Base Rate Margin
otherwise in effect during such period. After the occurrence of an Event of
Default and during the continuation thereof, all Euro-Rate Portions shall bear
interest (i) until the end of the then current Euro-Rate Interest Period for
each such Euro-Rate Portion, at a rate per annum which shall be two hundred
(200) basis points (2%) above the sum of (A) the Euro-Rate, (B) the Applicable
Euro-Rate Margin otherwise in effect during such period and (ii) at the end of
the then current Euro-Rate Interest Period for each such Euro-Rate Portion, such
Euro-Rate Portions shall automatically be converted to the Base Rate Portion,
and thereafter the interest rate shall be calculated in accordance with the
initial sentence of this Section 2.08(c).

           (d) Interest Periods; Limitations on Elections. At any time when the
Borrower shall select, convert to or renew the Euro-Rate Option to apply to all
or any portion of the outstanding Revolving Credit Loans, it shall elect one or
more Euro-Rate Interest Periods as the case may be. All the foregoing, however,
is subject to the following:

               (i) any Euro-Rate Interest Period which would otherwise end on a
day which is not a Business Day shall be extended to the next Business Day
unless such Business Day falls in the succeeding calendar month in which case
such Euro-Rate Interest Period shall end on the next preceding Business Day; and

               (ii) any Euro-Rate Interest Period which begins on the last day
of a calendar month or on a day for which there is no numerically corresponding
day in the subsequent calendar month during which such Euro-Rate Interest Period
is to end shall end on the last Business Day of such subsequent month.

               Elections by the Borrower of the Euro-Rate Option shall be
subject to the following limitations:

               (i) The Euro-Rate Portion for each Euro-Rate Interest Period
shall be in an aggregate principal amount of $5,000,000 or more; provided,
however, that each increment in excess of $5,000,000 shall be $1,000,000 or an
integral multiple thereof;

               (ii) No Euro-Rate Interest Period may be elected at any time that
a Default or an Event of Default shall have occurred and be continuing;

               (iii) No Euro-Rate Interest Period may be elected which would end
later than the Expiration Date;

               (iv) No Euro-Rate Interest Period may be elected with regard to
amounts outstanding which would be in excess of the Revolving Credit Commitment;
and

               (v) At no time may there be more than seven (7) separate Euro-
Rate Interest Periods in effect; provided, however, if any Revolving Credit
Loans are

                                       22
<PAGE>
 
outstanding bearing interest at the Base Rate Option, there may not be more than
six (6) separate Euro-Rate Interest Periods in effect.

          (e) Election, Renewal or Conversion of Interest Rate Options.
Elections or renewals of, or conversions to, the Base Rate Option shall continue
in effect until converted or renewed as hereinafter provided. Elections or
renewals of, or conversions to, the Euro-Rate Option shall expire as to each
Euro-Rate Portion at the expiration of the applicable Euro-Rate Interest Period.
At any time with respect to the Base Rate Portion or at the expiration of the
applicable Euro-Rate Interest Period with respect to any Euro-Rate Portion, the
Borrower may cause (subject to Subsection 2.08(d)) all or any part of the
principal amount of such Portion to be converted to, or to be renewed under, the
Euro-Rate Option by notice to the Agent as hereinafter provided. Such notice (i)
shall be irrevocable, (ii) shall be given not later than noon (Pittsburgh,
Pennsylvania time) in the case of a conversion to or renewal of, either in whole
or in part, the Euro-Rate Option, not less than three (3) Business Days prior to
the proposed effective date for such conversion or renewal, and (iii) shall set
forth:

                 (A) the effective date of such conversion or renewal, which
shall be a Business Day;

                 (B) the new Euro-Rate Interest Period(s) selected; and

                 (C) with respect to each such Euro-Rate Interest Period, the
aggregate principal amount of the corresponding Euro-Rate Portion.

At the expiration of each Euro-Rate Interest Period, any part (including the
whole) of the principal amount of the corresponding Euro-Rate Portion as to
which no notice of conversion or renewal has been received shall automatically
be converted to the Base Rate Option. The Agent shall promptly notify the
Borrower and the Lenders of any such automatic conversion.

          (f) Notification of Election of an Interest Rate Option. The Borrower,
by an Authorized Officer, shall notify the Agent of each election of an Interest
Rate Option, each conversion from one Interest Rate Option to another, the
amount of the Revolving Credit Loans then outstanding to be allocated to each
Interest Rate Option and, where relevant, the Euro-Rate Interest Periods as
provided for in this Agreement. Any such communication may be oral or written
and if oral it shall be followed promptly by written confirmation of such
Interest Rate Option election executed by an Authorized Officer of the Borrower.

          (g) Calculation of Interest. Interest on the Base Rate Portion shall
be calculated on the basis of a 365 or 366 day year, as the case may be, and the
actual days elapsed. Interest on each Euro-Rate Portion shall be calculated on
the basis of a 360-day year and the actual days elapsed. The calculation of the
amount of interest due and owing to the Lenders shall be evidenced by posting
the amount of interest due under the Revolving Credit Notes to the Loan Account
established by the Agent pursuant to Section 2.14.

          (h) Lawful Interest Rates Intended. In no event whatsoever shall the
interest rates charged hereunder exceed the highest rate permissible under any
law which a court of competent jurisdiction shall, in a final determination,
deem applicable hereto. In the event that such a court determines that any
Lender has received interest hereunder in excess of the highest applicable rate,
such Lender shall promptly refund such excess to the Borrower,
                                       23
<PAGE>
 
     or at such Lender's option, apply such excess in reduction of the principal
     balance of the Lender Obligations owing to the affected Lender.

          2.09. Prepayments: Allocation of Repayments.

                (a) Prepayments of Base Rate Portion. The Borrower, upon oral or
     written notice to the Agent by an Authorized Officer of Borrower given not
     later than 12:00 noon (Pittsburgh, Pennsylvania time) on the proposed date
     for prepayment, may prepay without penalty or premium any or all of the
     Base Rate Portion. Any oral notice of election hereunder shall be followed
     immediately by written confirmation of such prepayment election executed by
     an Authorized Officer of Borrower.

                (b) Prepayments of Euro-Rate Portions. Except as otherwise
     provided in Section 2.10(c), the Borrower, upon oral or written notice to
     the Agent by an Authorized Officer of Borrower given at least three (3)
     Business Days prior to the proposed date for repayment, may prepay, all or
     part of such Euro-Rate Portion; provided, such prepayment is in a minimum
     amount of $5,000,000 and if in excess of $5,000,000 in integral multiples
     of $1,000,000. If the Borrower prepays a Euro-Rate Portion other than on
     the last day of the Euro-Rate Interest Period applicable thereto, the
     Borrower agrees to pay, in addition to the other amounts set forth in this
     Section 2.09(b), such additional amounts as may be necessary to compensate
     each Lender for any loss (including loss of profit on a pre-tax basis) and
     any direct or indirect costs, including the costs of reemployment of funds
     prepaid at rates lower than the cost to such Lender of such funds. Such
     losses and costs shall be specified in writing to the Borrower by the
     affected Lenders (and such specifications shall set forth in reasonable
     detail the calculation of such losses and costs, including the Borrower's
     share of such losses and costs) and such specifications shall, absent
     manifest error, be binding and conclusive on the Borrower. Such prepayment
     shall include the then outstanding principal amount of the Euro-Rate
     Portion being prepaid together with accrued interest, fees and other
     amounts then due and payable on the amount prepaid, to the day of such
     prepayment. Except as provided in this Section 2.09(b), there shall be no
     voluntary prepayment of any Euro-Rate Portion.

                (c) Allocation of Repayments of Principal. Any voluntary
     prepayment pursuant to this Section 2.09 hereof shall be applied first to
     the repayment of any Euro-Rate Portion of the Revolving Credit Loans for
     which its associated Euro-Rate Interest Period expires on the date of such
     payment, second, to the reduction of the Base Rate Portion of the Revolving
     Credit Loans, and third, to the reduction of such Euro-Rate Portions of the
     Revolving Credit Loans as directed by the Borrower, and if the Borrower
     fails to give such directions, or if a Default or Event of Default has
     occurred and is continuing, to the reduction of such Euro-Rate Portions of
     the Revolving Credit Loans as the Agent may select in its sole and absolute
     discretion. Any reduction in any Euro-Rate Portion on a date other than the
     date on which its associated Euro-Rate Interest Period expires may result
     in a funding loss for which the Borrower will owe the Lenders an indemnity
     payment pursuant to Section 2.10 hereof.

          2.10. Yield Protection.

                (a) If any change subsequent to the Closing Date in any Law or
     in the interpretation or application thereof by any Official Body or in the
     compliance with any guideline or request from any Official Body, shall make
     it unlawful for any Lender to maintain or give effect to its obligations as
     contemplated under the Revolving Credit Commitment or for the Swingline
     Lender to maintain or give effect to its obligation to make Swingline
     Loans, such 

                                       24
<PAGE>
 
     Lender shall notify the Borrower and the Agent in writing of its
     determination of such unlawfulness and an explanation thereof. Thereafter,
     such Lender's obligation to make available any further Revolving Credit
     Loans hereunder, and the Swingline Lender's obligation to make available
     any further Swingline Loans hereunder shall forthwith be cancelled and the
     Borrower, within thirty (30) days, or within such longer period as may be
     allowed by Law, if any, shall repay to such Lender or Swingline Lender so
     affected its Ratable Share of the outstanding principal amount of all
     Revolving Credit Loans and/or Swingline Loans, together with interest
     thereon to the date of repayment and fees, if any, due as of the date of
     termination; provided, however, that the affected Lender's or Swingline
     Lender's obligations which are lawful, if severable from those which are
     unlawful, shall continue, and with respect to those obligations, this
     Agreement shall not terminate.

          (b) If any Law issued after the Closing Date (including, without
     limitation, Regulation D of the Federal Reserve Board), or if any change on
     or after the Closing Date in any Law (including, without limitation,
     Regulation D) or in the interpretation thereof by any Official Body charged
     with the administration thereof, shall

              (i) subject any Lender or Swingline Lender to any tax, levy,
     impost, charge, fee, duty, deduction or withholding or any kind hereunder
     (other than any tax imposed or based upon the income of such Lender or
     Swingline Lender and payable to any governmental or taxing authority in the
     United States of America, any state or any municipality thereof); or

              (ii) change the basis of taxation of any Lender or Swingline
     Lender with respect to payments of principal or interest or other amounts
     due hereunder (other than any change which affects, and only to the extent
     that it affects, the taxation by the United States, any state or any
     municipality thereof based upon the income of such Lender or Swingline
     Lender); or

              (iii) impose, modify or deem applicable any reserve, special
     deposit or similar requirements against assets held by any Lender or
     Swingline Lender (other than such requirements which result solely from a
     change in the credit quality of the Borrower or which are included in the
     determination of the applicable rate of interest hereunder); or

              (iv) impose upon any Lender or Swingline Lender any other
     obligation or condition with respect to this Agreement,

     and the result of any of the foregoing is to increase the cost to any
     Lender or Swingline Lender, to decrease the yield to any Lender or
     Swingline Lender with respect to the Revolving Credit Loans, the Swingline
     Loans or any Letters of Credit, to reduce the income receivable by any
     Lender or Swingline Lender or to impose any expenses upon any Lender or
     Swingline Lender with respect to the Revolving Credit Loans, the Swingline
     Loans or any Letters of Credit by an amount which any Lender or Swingline
     Lender reasonably deems material, then and in any such case:

                  (A) the Lender or Swingline Lender so affected shall promptly
     notify the Borrower and the Agent of the happening of such event;

                                       25
<PAGE>
 
                  (B) the Borrower shall pay to the affected Lender or Swingline
Lender, within five (5) Business Days of written demand such amount as will
compensate such Lender or Swingline Lender for such additional cost or reduced
amount, calculated from the date of the notification by such Lender or Swingline
Lender; and

                  (C) the Borrower may pay to such affected Lender or Swingline
Lender the affected Revolving Credit Loan or Swingline Loan in full without the
payment of any additional amount other than on account of such Lender's or
Swingline Lender's out-of-pocket losses (including funding losses, if any, as
provided in paragraph (c) below) not otherwise provided for in subparagraph (B)
immediately above.

The Lender or Swingline Lender so affected shall present to the Borrower and the
Agent a certificate setting forth such increased cost or reduced amount. Such
certificate shall set forth in reasonable detail the calculation of the amount
due and such Lender's or Swingline Lender's reasons for invoking the provisions
of this Section 2.10(b). Such certificate shall be conclusive evidence of the
amount due thereunder except in the case of manifest error in computation.

          (c) The Borrower agrees to indemnify each Lender and Swingline Lender,
on demand, against any loss or expense (including loss of profit) which such
Lender or Swingline Lender may sustain or incur in liquidating or employing
deposits from third parties acquired to effect, fund or maintain such Euro-Rate
Portions or any part thereof as a consequence of (i) the failure of the Borrower
to make a payment on the due date thereof, (ii) the failure of the Borrower to
borrow under, convert to or renew under the Euro-Rate Option on the proposed
effective date of such borrowing, conversion or renewal, or (iii) the payment,
prepayment or conversion by the Borrower of any Euro-Rate Portions for any
reason on a day other than the last day of the applicable Euro-Rate Interest
Period. Any Lender's or Swingline Lender's determination of an amount payable
under this paragraph (c) shall be conclusive absent manifest error.

          (d) The foregoing notwithstanding, if the affected Lender or Swingline
Lender can mitigate or eliminate such increased cost or reduced yield by
transferring the Loans to another existing lending office of such Lender or
Swingline Lender, such Lender or Swingline Lender agrees to so transfer the
Loans; provided, such transfer would not subject such Lender or Swingline Lender
to any unreimbursed cost or expense and would not otherwise be disadvantageous
to such Lender or Swingline Lender.

          2.11. Special Provisions Relating to the Euro-Rate Option.

                (a) Euro-Rate Unascertainable. In the event that on any date on
which a Euro-Rate Option would otherwise be set, the Agent shall have determined
(which determination shall be final and conclusive) that, by reason of
circumstances affecting the London interbank market, adequate, reasonable means
do not exist for ascertaining the Euro-Rate, the Agent shall give prompt notice
of such determination to the Borrower and the Lenders. Until the Agent notifies
the Borrower and the Lenders that the circumstances giving rise to such
determination no longer exist (which notice shall be given promptly following
receipt of knowledge thereof by the Agent), the right of the Borrower to borrow
under, convert to or renew the Euro-Rate Option shall be suspended. Any notice
of borrowing under, conversion to or renewal of the Euro-Rate Option which was
to become effective during the period of such suspension shall be treated as a
request to borrow under, convert to or renew the Base Rate Option with respect
to the principal amount therein specified.

                                       26
<PAGE>
 
                (b) Inability to Offer Euro-Rate. In the event that any Lender
     shall determine, in its sole discretion, that it is unable to obtain
     deposits in the London interbank market in sufficient amounts and with
     maturities related to such Euro-Rate Portions which would enable such
     Lender to fund such Euro-Rate Portions, then such Lender shall notify the
     Borrower and the Agent that the right of the Borrower to borrow under,
     convert to or renew the Euro-Rate Option, shall be suspended with respect
     to such Lender. Such notice shall set forth in reasonable detail such
     Lender's reasons for invoking the provisions of this Section 2.11(b).
     Following notification of the suspension of the Euro-Rate Option with
     respect to such Lender, the Borrower agrees to negotiate with such Lender
     for a modified or alternative fixed rate of interest, which will allow such
     Lender to realize its anticipated and bargained-for yield. In the event
     that the Borrower and such Lender cannot agree on a modified or alternative
     fixed rate of interest, any notice of borrowing under, conversion to or
     renewal of the Euro-Rate Option which was to become effective during the
     period of suspension shall be treated as a request to borrow under, convert
     to or renew the Base Rate Option with respect to the principal amount
     specified therein attributable to such Lender.

                (c) Illegality. If any Lender shall determine in good faith
     (which determination shall be final and conclusive) that compliance with
     any Law (whether or not having the force of law) or the interpretation or
     application thereof by any Official Body, has made it unlawful or
     impractical for such Lender to make or maintain the Revolving Credit Loans
     under the Euro-Rate Option, such Lender shall give notice of such
     determination to the Borrower and the Agent, which notice shall set forth
     in reasonable detail such Lender's reasons for invoking the provisions of
     this Section 2.11(c). Notwithstanding any provision of this Agreement to
     the contrary, unless and until such Lender shall have given notice to the
     Borrower and the Agent that the circumstances giving rise to such
     determination no longer apply (which notice shall be given promptly
     following receipt of knowledge thereof by such Lender):

                (i) with respect to any Euro-Rate Interest Periods thereafter
     commencing, interest in an amount equal to such Lender's Ratable Share of
     the corresponding Euro-Rate Portion shall be computed and payable under the
     Base Rate Option; and

                (ii) on such date, if any, as shall be required by law, an
     amount equal to such Lender's Ratable Share of any Euro-Rate Portion, as
     the case may be, then outstanding shall be automatically converted to the
     Base Rate Option and the Borrower shall pay to such Lender the accrued and
     unpaid interest, if any, on such amounts to (but not including) such
     conversion date.

     The Borrower shall pay any such Lender any additional amounts reasonably
     necessary to compensate such Lender for any costs incurred by such Lender
     as a result of any conversion pursuant to clause (ii) above which occurs on
     a day other than the last day of the relevant Euro-Rate Interest Period,
     including, but not limited to, any interest or fees payable by such Lender
     to lenders of funds obtained by them to loan or maintain the lending of the
     Revolving Credit Loans so converted. Such Lender shall furnish to the
     Borrower and the Agent a certificate as to the amount necessary to
     compensate it for such costs, which certificate shall set forth in
     reasonable detail the calculation of the amount due. Such certificate shall
     constitute conclusive evidence of the amount due thereunder absent any
     manifest error in computation. The Borrower shall pay such amount to such
     Lender, as additional consideration hereunder, within ten (10) days of the
     Borrower's receipt of such certificate.

                                       27
<PAGE>
 
                (d) The foregoing notwithstanding, if the affected Lender can
continue to offer the Euro-Rate Option to the Borrower by transferring the
Revolving Credit Loans to another existing lending office of such Lender, such
Lender agrees to so transfer the Revolving Credit Loans; provided, such transfer
would not subject such Lender to any unreimbursed cost or expense and would not
otherwise be disadvantageous to such Lender.

          2.12. Capital Adequacy. If after the Closing Date (i) any adoption of
or any change in or in the interpretation by an Official Body of any Law or (ii)
compliance with any Law, guideline or request of any Official Body exercising
control over banks or financial institutions generally or any court (whether or
not having the force of law), affects or would affect the amount of capital
required or expected to be maintained by any Lender, L/C Issuer or Swingline
Lender or any corporation controlling such Lender, L/C Issuer or Swingline
Lender other than those resulting solely from a change in the credit quality of
the Borrower (a "CAPITAL ADEQUACY EVENT"), and the result of such Capital
Adequacy Event is to reduce the rate of return on capital of such Lender, L/C
Issuer or Swingline Lender or any corporation controlling such Lender, L/C
Issuer or Swingline Lender as a consequence thereof to a level below that which
such Lender, L/C Issuer or Swingline Lender could have achieved but for such
Capital Adequacy Event, taking into consideration such Lender's, L/C Issuer's or
Swingline Lender's policies with respect to capital adequacy, by an amount which
such Lender, L/C Issuer or Swingline Lender deems to be material, such Lender,
L/C Issuer or Swingline Lender shall promptly deliver to the Borrower and the
Agent a statement of the amount necessary to compensate such Lender, L/C Issuer
or Swingline Lender for the reduction in the rate of return on its capital
attributable to the commitments under this Agreement or any of the Loan
Documents (the "CAPITAL COMPENSATION AMOUNT"). Each Lender, L/C Issuer and
Swingline Lender shall determine the Capital Compensation Amount in good faith,
using reasonable attribution and averaging methods. Each Lender, L/C Issuer and
Swingline Lender shall, from time to time, furnish to the Borrower and the Agent
a certificate setting forth the amount so determined and the calculations of
such amount. Such certificate shall constitute conclusive evidence of the amount
due thereunder absent any manifest error in computation. Such amount shall be
due and payable by the Borrower to such Lender, L/C Issuer or Swingline Lender
ten (10) days after such notice is given. As soon as practicable after any
Capital Adequacy Event, such Lender shall submit to the Borrower and the Agent
estimates of the Capital Compensation Amounts that would be payable as a
function of such Lender's, L/C Issuer's or Swingline Lender's Revolving Credit
Commitment hereunder.

          2.13. Swingline Loans.

                (a) Swingline Option. Subject to the provisions of this Section
2.13, the Swingline Lender agrees that the Borrower may request that Swingline
Loans, in an aggregate amount at any one time outstanding not to exceed the
lesser of (i) $5,000,000 or (ii) an amount which, when added to the aggregate
principal amount of (A) all other Loans then outstanding, (B) the aggregate
Stated Amount of outstanding Letters of Credit issued pursuant to Section 2.17
and (C) the aggregate amount of Unreimbursed L/C Draws does not exceed
$70,000,000. The Swingline Lender shall have no obligation to make Swingline
Loans hereunder on or after the Expiration Date.

                (b) Limitations on and Evidence of Swingline Loans. Each
Swingline Loan or repayment of a Swingline Loan must be in the minimum principal
amount of $500,000 or, if in excess of $500,000, in integral multiples of
$500,000. Swingline Loans shall be repaid on the date agreed upon by the
Borrower and the Swingline Lender, not more than five (5) days
     

                                       28
<PAGE>
 
after the making of the Swingline Loan and not after the Expiration Date. The
obligation of the Borrower to repay, prior to the Expiration Date, the aggregate
unpaid principal amount of such Swingline Loans advanced by the Swingline Lender
shall be evidenced by the Swingline Note substantially in the form of Exhibit 
"A-2" hereto. The principal amount actually due and owing the Swingline Lender
shall be the aggregate unpaid principal amount of all disbursements of Swingline
Loans made by the Swingline Lender, all as shown on such the Loan Account
established pursuant to Section 2.14.

                (c) Swingline Loan Procedure. The Borrower may from time to time
from the Closing Date to the Business Day prior to the Expiration Date request a
Swingline Loan. Such request shall be made not later than noon (Pittsburgh,
Pennsylvania time) on the date of the proposed Swingline Loan. Such request may
be made to the Agent orally or in writing and if orally confirmed in writing, it
being understood that the Agent may rely on the authority of any person making
such a telephone request without the necessity of receipt of such written
confirmation. The Agent shall promptly notify the Swingline Lender of such
request. The Swingline Lender shall make the Swingline Loan available to the
Borrower not later than 3:00 P.M. (Pittsburgh, Pennsylvania time) on the same
Business Day such Swingline Loan is requested. The Swingline Lender shall
confirm in writing to the Borrower the terms of such Swingline Loan not later
than 3:00 P.M. (Pittsburgh, Pennsylvania time) on the Business Day following the
day such Swingline Loan is requested.

                (d) Swingline Loan Interest. Interest on the Swingline Loans
shall accrue at a rate per annum as offered by the Swingline Lender and accepted
by the Borrower. After the occurrence of an Event of Default and during the
continuation thereof whether or not judgment has been entered on the Notes, the
Swingline Loans shall bear interest at a rate per annum which shall be two
hundred (200) basis points (2%) above the Base Rate Option otherwise in effect
for Revolving Credit Loans during such period.

                (e) Risk Participation. Upon the disbursement of each Swingline
Loan and without any further action by or on behalf of such Lender, each Lender
hereby agrees to purchase, upon the occurrence of an Event of Default, an
undivided, full risk, nonrecourse participation in such Swingline Loan, in an
amount equal to (i) such Lender's Ratable Share (ii) multiplied by the
outstanding principal amount of such Swingline Loan on the date of the Event of
Default; provided, however, no Lender shall participate in any Swingline Loan
made after a notice of an Event of Default has been delivered pursuant to this
Agreement. If and to the extent the Swingline Lender receives payment of
principal or interest on a participated Swingline Loan, the Swingline Lender
shall deliver to each Lender such Lender's Ratable Share of such payment.

          2.14 Loan Account. The Agent shall open and maintain on its books a
Loan Account in the name of the Borrower, with respect to (i) Revolving Credit
Loans and Swingline Loans made, repayments and prepayments of the principal
thereof, and the computation and payment of interest thereon, (ii) Letters of
Credit issued, or participated in, as the case may be, and draws and
reimbursements thereon or thereof, and (iii) the computation and payment of the
Fees due hereunder to the Lenders, the L/C Issuer, the Swingline Lender and the
Agent, and the computation of other amounts due and sums paid to the Agent
hereunder. Upon the request of the Borrower to the Agent, the Agent shall
promptly furnish to the Borrower a statement of the Loan Account. The failure to
record any such amount shall not limit or otherwise affect the obligations of
the Borrower hereunder or under the Notes to repay all amounts owed hereunder
and thereunder together with all interest accrued thereon and all 

                                       29
<PAGE>
 
other fees and charges provided herein. The Loan Account shall be conclusive
evidence as to the amount at any time due to the Lenders, the L/C Issuer, the
Swingline Lender and the Agent from the Borrower except in the case of manifest
error.

          2.15. All Advances to Constitute One Loan. Notwithstanding the
limitations set forth herein, all Revolving Credit Loans, the Swingline Loans
and all other Lender Obligations shall constitute one loan and all Indebtedness
and obligations of the Borrower to the Lenders under this Agreement and all
other Loan Documents shall constitute a general obligation of the Borrower. The
parties hereto agree that all of the rights of the Agent, the L/C Issuer, the
Swingline Lender, the Lenders and the Borrower set forth in this Agreement and
the other Loan Documents shall apply to any amendment or modification of or
supplement to this Agreement and the other Loan Documents.

          2.16. Use of Proceeds. The proceeds of the Revolving Credit Loans and
the Swingline Loans shall be used exclusively (i) to pay interest, Fees and
other costs, and expenses hereunder and under the other Loan Documents, (ii) to
repay any Unreimbursed L/C Draw, (iii) to repay in full any amounts outstanding
under the Prior Credit Agreement, (iv) assume reimbursement obligations under
Existing Letters of Credit, and (v) to fund capital expenditures, working
capital, acquisitions and general corporate purposes of the Borrower and its
Subsidiaries including, without limitation, stock repurchases to the extent
permitted hereby. No proceeds of any Loan may be used for any purpose which
contravenes applicable law or any provision of any Loan Document.

          2.17. Letter of Credit Subfacility.

                (a) At the request of the Borrower, the L/C Issuer will issue
for the account of the Borrower, on the terms and conditions hereinafter set
forth (including without limitation Article V hereof), one or more Letters of
Credit; provided, however, no Letter of Credit shall have an expiry date later
than the earlier of twelve (12) months from the date of issuance or fifteen (15)
days prior to the Expiration Date; and provided, further, however, that in no
event shall (i) the Stated Amount of the Letters of Credit issued pursuant to
this Section 2.17 exceed, at any one time, $30,000,000, or (ii) the sum of
aggregate outstanding principal balance of the Revolving Credit Loans, the
aggregate unpaid balance of outstanding Swingline Loans, the aggregate unpaid
balance of any Unreimbursed L/C Draws and the aggregate Stated Amount of the
Letters of Credit issued by the L/C Issuer under this Section 2.17 exceed, at
any one time, the aggregate Revolving Credit Commitments.

                (b) (i) The Borrower shall pay (A) to the L/C Issuer for its own
account a fronting fee equal to 1/8 of 1% per annum (the "L/C FRONTING FEE") on
the aggregate daily (computed at the opening of business and on the basis of a
year of 360 days and actual days elapsed) Stated Amount of the outstanding
Letters of Credit for the period in question, and (B) to the Agent for the
ratable account of the Lenders a fee (the "LETTER OF CREDIT FEE") equal to the
Applicable Letter of Credit Fee per annum, as determined below, on the aggregate
daily (computed at the opening of business and on the basis of a year of 360
days and actual days elapsed) Stated Amount of the outstanding Letters of Credit
for the period in question. The Letter of Credit Fee and the L/C Fronting Fee
shall be payable (A) quarterly in arrears on the last Business Day of each
Fiscal Quarter occurring during the term of this Agreement, (B) on the
Expiration Date or (C) upon acceleration of the Notes. Any issuance of an
amendment to extend the stated expiration date of a Letter of Credit or an
amendment to increase the Stated Amount of a Letter of Credit shall be treated
as an issuance of a new Letter of Credit for

                                       30
<PAGE>
 
     purposes of calculation of the Letter of Credit Fee and the L/C Fronting
     Fee due and payable hereunder. After the occurrence of an Event of Default
     and during the continuation thereof, the rate at which the Letter of Credit
     Fee is calculated shall be increased by two hundred (200) basis points (2%)
     above the pre-default rate.

                (ii) The Borrower shall also pay to the L/C Issuer for the L/C
     Issuer's own account the L/C Issuer's customary documentation fees payable
     with respect to the Letters of Credit as the L/C Issuer may generally
     charge from time to time. Without limitation, the foregoing shall include
     all charges and expenses paid or incurred by the L/C Issuer in connection
     with any Letter of Credit, including without limitation: (A)
     correspondents' charges, if any, (B) any and all reasonable out-of-pocket
     expenses and charges of the L/C Issuer in connection with the performance,
     administration, interpretation, collection and enforcement of this
     Agreement and any Letter of Credit, including all reasonable legal fees and
     expenses, and (C) any and all applicable reserve or similar requirements
     and any and all premiums, assessments, or levies imposed upon the L/C
     Issuer by any Official Body.

                (iii) If by reason of (A) any change in any Law or any change in
     the interpretation or application by any judicial or regulatory authority
     of any Law or (ii) compliance by the L/C Issuer with any direction, request
     or requirement (whether or not having the force of law) of any Official
     Body:

                      (A) the L/C issuer shall be subject to any tax, levy,
     charge or withholding of any nature or to any variation thereof or to any
     penalty with respect to the maintenance or fulfillment of its obligations
     under this Section 2.17, whether directly or by such being imposed on or
     suffered by the L/C Issuer;

                      (B) any reserve, deposit or similar requirement is or
     shall be applicable, imposed or modified in respect of the Letters of
     Credit; or

                      (C) there shall be imposed on the L/C Issuer any other
     condition regarding this Section 2.17 or the Letters of Credit;

     and if the result of any of the foregoing is to directly or indirectly
     increase the cost to the L/C Issuer of issuing or maintaining any Letter of
     Credit, or to reduce the amount receivable in respect thereof by, the L/C
     Issuer, then and in any such case the L/C Issuer may, at any time after the
     additional cost is incurred or the amount receivable is reduced, notify the
     Borrower and the Agent, and the Borrower shall pay on demand such amounts
     as the L/C Issuer may specify to be necessary to compensate the L/C Issuer
     for such additional cost or reduced receipt, together with interest on such
     amount from the date of the notice of such event which results in such
     increased cost or reduction in amount receivable until payment in full
     thereof at a rate equal at all times to the Base Rate. The determination by
     the L/C Issuer of any amount due pursuant to this Subsection 2.17(b)(ii) as
     set forth in a certificate setting forth the calculation thereof, shall, in
     the absence of manifest error, be final and conclusive and binding on all
     of the parties hereto.

     For purposes of this Agreement, the term "APPLICABLE LETTER OF CREDIT FEE"
     shall mean the rate per annum set forth in the chart below which
     corresponds to the range of ratios in which the Borrower's Consolidated
     Total Indebtedness to Consolidated EBITDA Ratio as at the end of the
     preceding Fiscal Quarter falls:

                                       31
<PAGE>
 
<TABLE>
<CAPTION>
                    Consolidated Total Indebtedness                           Applicable Letter of
                     to Consolidated EBITDA Ratio                                  Credit Fee
------------------------------------------------------------------------------------------------------
<S>                                                                       <C>
Less than or equal to 1.0 to 1.0                                                       .75%
------------------------------------------------------------------------------------------------------
Greater than 1.0 to 1.0 but less than or equal to 1.5 to 1.0                          1.00%
------------------------------------------------------------------------------------------------------
Greater than 1.5 to 1.0 but less than or equal to 2.0 to 1.0                          1.25%
-----------------------------------------------------------------------------------------------------
Greater than 2.0 to 1.0 but less than or equal to 2.5 to 1.0                          1.50%
-----------------------------------------------------------------------------------------------------
Greater than 2.5 to 1.0                                                               1.75%
-----------------------------------------------------------------------------------------------------
</TABLE>

All adjustments shall be determined as of the date the Borrower's financial
statements and Compliance Certificate are required to be delivered pursuant to
items (i), (ii) and (iii) of Section 6.02.  The foregoing notwithstanding, the
Applicable Letter of Credit Fee from the Closing Date to and including the
December 1998 Delivery Date shall be 1.00%.

                (c) Immediately upon the issuance of each Letter of Credit and
each increase in the Stated Amount thereof, each Lender hereby agrees to
irrevocably purchase and shall be deemed to have irrevocably purchased from the
L/C Issuer an undivided, full risk, non-recourse participation in such Letter of
Credit and drawings thereunder in an amount equal to such Lender's Ratable Share
of the maximum amount which is or at any time may become available to be drawn
thereunder. In the event that the L/C Issuer is required for any reason to
refund or repay to the Borrower, any guarantor or any other Person all or any
portion of any amount remitted to the L/C Issuer pursuant to this Agreement, the
Lenders shall promptly remit to the L/C Issuer, upon three (3) Business Days'
demand therefor, their respective Ratable Shares of the amount which is so
refunded or repaid.

                (d) In the event any restrictions are imposed upon the L/C
Issuer or any of the Lenders by any Law of any Official Body having jurisdiction
over the banking activities of the L/C Issuer or any Lender which would prevent
the L/C Issuer from issuing the Letters of Credit or amending the Letters of
Credit or would prevent any Lender from honoring its obligations under this
Section 2.17, the commitment of the L/C Issuer to issue the Letters of Credit or
enter into any amendment with respect thereto shall be immediately suspended. If
any Lender believes any such restriction would prevent such Lender from honoring
its obligations under this Section 2.17, it shall promptly notify the Agent. The
Agent shall promptly notify the Borrower, the L/C Issuer and the other Lenders
of the existence and nature of (i) any restriction which would cause the
suspension of the commitment of the L/C Issuer to issue the Letters of Credit or
to enter into amendments with respect thereto and (ii) any restriction which
would prevent any Lender from honoring its obligations under this Section 2.17.
The Borrower will thereupon undertake reasonable efforts to obtain the
cancellation of all outstanding Letters of Credit; provided, however, that the
refusal of any beneficiary of a Letter of Credit to surrender such Letter of
Credit will not be an Event of Default hereunder, provided that the Borrower
shall undertake good faith efforts to obtain substitute letters of credit for
the then existing and outstanding Letters of Credit. Nothing contained in this
Section 2.17 shall be deemed a termination of the Revolving Credit Commitments
and, in the event of a suspension of the commitment of the L/C Issuer to issue
Letters of Credit as set forth above, the Borrower may continue to borrow under
the Revolving Credit Commitments provided the requirements of Section 5.02 are
complied with.

                                       32
<PAGE>
 
                (e) When the Borrower desires the issuance of a Letter of
     Credit, the Borrower shall deliver a duly completed Application for Letter
     of Credit to the L/C Issuer, with a copy to the Agent, no later than 11:00
     A.M. (Pittsburgh, Pennsylvania time) at least three (3) Business Days, or
     such shorter period as may be agreed to by the L/C Issuer, in advance of
     the proposed date of issuance. Upon satisfaction of the conditions set
     forth in Section 5.01 and, if applicable, Section 5.02, the L/C Issuer
     shall be obligated to issue the Letter of Credit and shall notify the Agent
     and each Lender of such issuance. In determining whether to pay under a
     Letter of Credit, the L/C Issuer shall be responsible only to determine
     that the documents and certificates required to be delivered under the
     Letter of Credit have been delivered and that they comply on their face
     with the requirements of the Letter of Credit.

                (f) In the event of any request for drawing under a Letter of
     Credit by the beneficiary thereof, the L/C Issuer shall immediately notify
     the Borrower and the Agent, and the Borrower shall reimburse, or cause the
     reimbursement of, the L/C Issuer on demand as set forth in the applicable
     Application for Letter of Credit in an amount in same day funds equal to
     the amount of such drawing; provided, however, that anything contained in
     this Agreement to the contrary notwithstanding, unless the Borrower shall
     have notified the Agent and the L/C Issuer prior to such time that the
     Borrower intends to reimburse the L/C Issuer for all or a portion of the
     amount of such drawing with funds other than the proceeds of Revolving
     Credit Loans, the Borrower shall be deemed to have given a Loan Request to
     the Agent requesting the Lenders to make Revolving Credit Loans on the
     first Business Day immediately following the date on which such drawing is
     honored in an aggregate amount equal to the excess of the amount of such
     drawing over the amount received by the L/C Issuer from such other funds in
     reimbursement thereof (the "UNREIMBURSED L/C DRAW"), plus accrued interest
     on such amount at the rate set forth in Subsection 2.08. Any such Revolving
     Credit Loan shall be deemed advanced to the Borrower. If the Borrower shall
     be deemed to have given a Loan Request, then, subject to satisfaction or
     waiver of the conditions specified in Section 5.02, the Lenders shall, all
     as set forth in Section 2.17(g) hereof, on the first Business Day
     immediately following the date of such drawing, make Revolving Credit Loans
     in the aggregate amount of the Unreimbursed L/C Draw plus accrued interest
     on such amount at the applicable rate set forth in Section 2.08. The
     proceeds of any such Revolving Credit Loans shall be applied directly by
     the Agent upon receipt from the Lenders to reimburse the L/C Issuer for the
     Unreimbursed L/C Draw plus accrued interest on such amount. The foregoing
     shall not limit or impair the obligation of the Borrower to reimburse the
     L/C Issuer on demand.

                (g) In the event that the Borrower shall fail to reimburse the
     L/C Issuer on demand as provided in the applicable Application for Letter
     of Credit and Section 2.17(f) above in an amount equal to the amount of any
     drawing honored by the L/C Issuer under a Letter of Credit plus accrued
     interest, the L/C Issuer shall promptly notify the Agent and each Lender of
     the Unreimbursed L/C Draw plus accrued interest on such amount of such
     drawing and of such Lender's respective participation therein. Each Lender
     shall make available to the L/C Issuer an amount equal to its respective
     participation in same day funds, at the office of the L/C Issuer specified
     in such notice, not later than 12:00 Noon (Pittsburgh, Pennsylvania time)
     on the Business Day after the date specified in such notice by the L/C
     Issuer. In the event that any Lender fails to make available to the L/C
     Issuer the amount of such Lender's participation in such Letter of Credit
     as provided in this Section 2.17(g), the L/C Issuer shall be entitled to
     recover such amount on demand from such Lender together with interest at
     the Federal Funds Effective Rate for three (3) Business Days and thereafter
     at the Base Rate. Nothing in this Section 2.17(g) shall be deemed to
     prejudice the right of any Lender to recover its Ratable Share of the
     Unreimbursed L/C Draw from the L/C Issuer pursuant to this Section 

                                       33
<PAGE>

2.17(g) in the event that it is determined by a court of competent jurisdiction
that payment with respect to a Letter of Credit by the L/C Issuer constituted
gross negligence or willful misconduct on the part of the L/C Issuer. The L/C
Issuer shall distribute to each Lender which has paid all amounts payable by it
under this Section 2.17(g) with respect to a Letter of Credit such other
Lender's Ratable Share of all payments received by the L/C Issuer from the
Borrower in reimbursement of drawing honored by the L/C Issuer under the Letter
of Credit when such payments are received.

                (h) The obligations of the Borrower under this Agreement to
reimburse the L/C Issuer for all drawings upon the Letters of Credit shall be
absolute, unconditional and irrevocable, and shall not be subject to any right
of set-off or counterclaim and shall be paid or performed strictly in accordance
with the terms of this Agreement, under all circumstances whatsoever, including
the following circumstances:

                    (i) any lack of validity or enforceability of this
Agreement, any Letter of Credit or any of the Loan Documents;

                    (ii) any amendment or waiver of any provision of all or any
of the Loan Documents;

                    (iii) the existence of any claim, set-off, defense or other
rights which the Borrower may have at any time against any beneficiary or any
transferee of any Letter of Credit (or any Persons for whom any such beneficiary
or any such transferee may be acting), the L/C Issuer, the Agent or any Lender
(other than the defense of payment to the L/C Issuer in accordance with the
terms of this Agreement) or any other Person, whether in connection with this
Agreement, the Loan Documents or any transaction contemplated hereby or thereby
or any unrelated transaction;

                    (iv) any draft, demand, certificate, statement or document
presented under any Letter of Credit, appearing on its face to be valid and
sufficient, but proving to be forged, fraudulent, invalid or insufficient in any
respect or any statement therein being untrue or inaccurate in any respect
whatsoever;

                    (v) payment by the L/C Issuer under any Letter of Credit
against presentation of any document which does not comply with the terms of the
Letter of Credit, provided that such payment shall not have constituted gross
negligence or willful misconduct of the L/C Issuer;

                    (vi) any other circumstance or happening whatsoever, whether
or not similar to any of the foregoing, not resulting from gross negligence or
willful misconduct of the L/C Issuer; and

                    (vii) the fact that a Default or Event of Default shall have
occurred and be continuing.

        (i) This Agreement is intended to supplement each Application for Letter
of Credit executed by the Borrower and delivered to the L/C Issuer. Whenever
possible this Agreement is to be construed as consistent with each Application
for Letter of Credit but, to the extent that the provisions of this Agreement
and each Application for Letter of Credit conflict, the terms of this Agreement
shall control.

                                       34
<PAGE>
 
        (j) Existing Letters of Credit. As of the Closing Date, each of the
Existing Letters of Credit issued by the L/C Issuer and outstanding on such date
for the account of the Borrower and identified on Schedule 2.17(j) shall be
deemed to be Letters of Credit issued hereunder and shall be subject to all of
the terms and provisions of this Agreement. The Borrower is hereby deemed to be
the account party with respect to each letter of credit listed on Schedule
2.17(j) hereunder for all purposes thereunder and hereunder. Each Lender agrees
that its obligations with respect to Letters of Credit pursuant to this
Agreement shall include such Existing Letters of Credit. With respect to each
such Existing Letter of Credit, for the period commencing on the Closing Date
the Borrower shall pay all fees and commissions set forth in this Agreement at
the times and in the manner herein set forth. The obligations of the Borrower
under each application for letter of credit and reimbursement agreement
(together with any related amendments) executed by the Borrower with respect to
the Existing Letters of Credit are hereby expressly assumed by the Borrower and
each such application for letter of credit and reimbursement agreement, as
amended, is hereby deemed an Application for Letter of Credit. The existing
reimbursement agreements shall be superseded in their entirety by this Agreement
which shall apply to Existing Letters of Credit set forth on Schedule 2.17(j) as
well as all Letters of Credit issued hereunder on and after the date hereof.

        (k) Obligations Absolute. Notwithstanding any other provision of this
Agreement, each Lender hereby agrees that its obligation to participate in each
Letter of Credit issued in accordance herewith and its obligation to make the
payments to be made by it under this Section 2.17 is absolute, irrevocable and
unconditional and shall not be affected by any event, condition or circumstance
whatever. The failure of any Lender to make any such payment shall not relieve
any other Lender of its funding obligation hereunder on the date due, but no
Lender shall be responsible for the failure of any other Lender to meet its
funding obligations hereunder.

        (l) In addition to amounts payable as elsewhere provided in this Section
2.17, the Borrower hereby agrees to protect, indemnify, pay and save the Agent
or the L/C Issuer harmless from and against any and all claims, demands,
liabilities, damages, losses, costs, charges and expenses (including reasonable
attorneys' fees) which the Agent or the L/C Issuer may incur or be subject to as
a consequence, direct or indirect, of (i) the issuance of the Letters of Credit
or any amendment thereto, other than as a result of the gross negligence or
willful misconduct of the Agent or the L/C Issuer as determined by a court of
competent jurisdiction, (ii) the failure of the L/C Issuer to honor a draw under
any Letter of Credit if the L/C Issuer in good faith and upon advice of counsel
believes that it is prohibited from making such payment as a result of any
requirement of Law or of any Official Body, or (iii) any material breach by the
Borrower of any representation, warranty, covenant, term or condition in, or the
occurrence of any default under, any document related to the issuance or any
amendment of the Letters of Credit. If any proceeding shall be brought or
threatened against the Agent or the L/C Issuer by reason of or in connection
with any event described in clauses (i) through (iii) above, the Agent shall
promptly notify the Borrower in writing, and the Borrower shall assume the
defense thereof, including the employment of counsel and payment of all costs of
litigation. Notwithstanding the preceding sentence, the Agent and the L/C Issuer
shall have the right to employ their own counsel and to determine its own
defense of such action in any such case, but the fees and expenses of such
counsel shall be at the expense of the Agent or the L/C Issuer, as the case may
be, unless (x) the employment of such counsel shall have been authorized in
writing by the Borrower, (y) the Borrower, after the aforementioned notice of
the action, shall not have employed counsel to have charge of such defense or
(z) if the position of 

                                       35
<PAGE>
 
the Borrower is adverse or contrary to the position advocated by the Agent or
the L/C Issuer, as the case may be. In each case described in clauses (x), (y)
and (z) immediately above the reasonable fees and expenses of counsel for the
Agent or the L/C Issuer, as the case may be shall be borne by the Borrower. The
Borrower shall not be liable for any settlement of any such action affected
without its consent.

        (m) The L/C Issuer is hereby expressly authorized and directed to honor
any request for payment which is made under and in compliance with the terms of
any Letter of Credit without regard to, and without any duty on the L/C Issuer's
part to inquire into, the existence of any disputes or controversies between the
Borrower, the beneficiary of any Letter of Credit or any other Person, or the
respective rights, duties or liabilities of any of them or whether any facts or
occurrences represented in any of the documents presented under any Letter of
Credit are true or correct. Furthermore, the Borrower fully understands and
agrees that the L/C Issuer's sole obligation to the Borrower shall be limited to
honoring requests for payment made under and in compliance with the terms of any
Letter of Credit, the Application for Letter of Credit therefor and this
Agreement and the L/C Issuer's obligation remains so limited even if the L/C
Issuer may have assisted the Borrower in the preparation of the wording of any
Letter of Credit or any documents required to be presented thereunder or that
the L/C Issuer may otherwise be aware of the underlying transaction giving rise
to any Letter of Credit and this Agreement.

        (n) As between the Borrower and the L/C Issuer, the Borrower assumes all
risks of the acts and omissions of, or misuse of the Letters of Credit by, the
beneficiaries of the Letters of Credit. In furtherance and not in limitation of
the foregoing, the L/C Issuer shall not be responsible: (i) for the form,
validity, sufficiency, accuracy, genuineness or legal effect of any document
submitted by any party in connection with the application for or the issuance or
amendment of the Letters of Credit, even if it should in fact prove to be in any
or all respects invalid, insufficient, inaccurate, fraudulent or forged; (ii)
for the validity or sufficiency of any instrument transferring or assigning or
purporting to transfer or assign the Letters of Credit or the rights or benefits
thereunder or proceeds thereof, in whole or in part, which may prove to be
invalid or ineffective for any reason; (iii) for failure of a beneficiary of a
Letter of Credit to comply fully with conditions required in order to draw upon
such Letter of Credit; (iv) for errors, omissions, interruptions or delays in
transmission or delivery of any messages, by mail, cable, telegraph, telecopy,
telex or otherwise, whether or not they be in cipher; (v) for errors in
interpretation of technical terms; (vi) for any loss or delay in the
transmission or otherwise of any document required in order to make a draw under
the Letters of Credit or of the proceeds thereof; (vii) for the misapplication
by a beneficiary of any Letter of Credit of the proceeds of any drawing under
such Letter of Credit; (viii) for any consequences arising from causes beyond
the control of the L/C Issuer, including, without limitation, any Law; and (ix)
for any other circumstances whatsoever in making or failing to make payment
under a Letter of Credit; except that the Borrower shall have a claim against
the L/C Issuer, and the L/C Issuer shall be liable to the Borrower, to the
extent, but only to the extent, of any direct, as opposed to consequential,
damages suffered by the Borrower by a court of competent jurisdiction to be the
result of (i) the L/C Issuer's willful misconduct or gross negligence in
determining whether documents presented under a Letter of Credit comply with the
terms of the Letter of Credit, (ii) the L/C Issuer's willful misconduct or gross
negligence in paying a draw under a Letter of Credit to any Person other than
the beneficiary of such Letter of Credit or its lawful successor, representative
or assign (or as otherwise directed in writing by the beneficiary of such Letter
of Credit) or (iii) the L/C Issuer's willful failure to pay under a Letter of
Credit after the presentation to it by the beneficiary of such Letter of Credit
or its lawful successor, 

                                       36
<PAGE>
 
representative or assign of a sight draft and certificate or other documents
strictly complying with the terms and conditions of such Letter of Credit,
unless the L/C Issuer in good faith and upon advice of counsel believes that it
is prohibited by law or other legal authority from making such payment. None of
the above shall affect, impair, or prevent the vesting of any of the L/C
Issuer's rights or powers hereunder.

        (o) Except for the L/C Issuer's obligations to issue Letters of Credit
hereunder and its obligations under such Letters of Credit, the L/C Issuer shall
have no liability to the Borrower from a reduction of the L/C Issuer's credit
rating or any deterioration in its financial condition.

        (p) The Borrower shall bear and pay all reasonable expenses of every
kind (including all reasonable attorneys' fees) of the enforcement of any of the
L/C Issuer's rights under this Agreement or the Letters of Credit, or of any
claim or demand by the L/C Issuer against the Borrower, or of any actual or
attempted sale, exchange, enforcement, collection, maintenance, retention,
insurance, compromise, settlement, release, delivery on trust receipt, or other
security agreement, or delivery of any such security, and of the receipt of
proceeds thereof, and will repay to the L/C Issuer any such expenses incurred by
the L/C Issuer.

        (q) In furtherance and extension and not in limitation of the specific
provisions hereinabove set forth, any action taken or omitted by the L/C Issuer
under or in connection with the Letters of Credit or the related sight drafts or
certificates or documents, if taken or omitted in good faith, shall not put the
L/C Issuer under any resulting liability to the Borrower.

        (r) Whenever appropriate to prevent unjust enrichment and to the end
that the Borrower shall bear substantially all of the risks relative to any
Letter of Credit and the underlying transactions, the L/C Issuer shall be
subrogated (for purposes of defending against the Borrower's claims and
proceeding against others to the extent of the L/C Issuer's liability to the
Borrower) to the Borrower's rights against any Person who may be liable to the
Borrower on any underlying transaction, to the rights of any holder in due
course or Person with similar status against the Borrower, and to the rights of
the beneficiary or its assignee or person with similar status against the
Borrower.

        (s) Except and to the extent inconsistent with the specific provisions
hereof, this Agreement, each Letter of Credit hereunder and all transactions in
connection therewith shall be interpreted, construed and enforced according to:
(i) the "Uniform Customs and Practice for Documentary Credits" (1993 Revision),
International Chamber of Commerce Publication No. 500 and subsequent revisions
thereof which shall supersede inconsistent provisions of applicable law to the
extent not prohibited by applicable law and (ii) the laws of the Commonwealth of
Pennsylvania, including, without limitation, the Uniform Commercial Code, and
excluding conflict of laws rules.

        2.18. Taxes.

        (a) No Deductions. All payments made by the Borrower hereunder and
under each Note shall be made free and clear of and without deduction for any
present or future taxes, levies, imposts, deductions, charges or withholdings,
and all liabilities with respect thereto, excluding taxes imposed on the net
income of any Lender, the L/C Issuer or the 

                                       37
<PAGE>
 
Swingline Lender and all income and franchise taxes applicable to any Lender,
the L/C Issuer or the Swingline Lender of the United States (all such non-
excluded taxes, levies, imposts, deductions, charges, withholdings and
liabilities being hereinafter referred to as "TAXES"). If the Borrower shall be
required by Law to deduct any Taxes from or in respect of any sum payable
hereunder or under any Note, (i) the sum payable shall be increased as may be
necessary so that after making all required deductions (including deductions
applicable to additional sums payable under this Section 2.18(a)) each Lender,
the L/C Issuer and the Swingline Lender receives an amount equal to the sum it
would have received had no such deductions been made, (ii) the Borrower shall
make such deductions and (iii) the Borrower shall timely pay the full amount
deducted to the relevant tax authority or other authority in accordance with
applicable law.

          (b) Stamp Taxes. In addition, the Borrower agrees to pay any present
or future stamp or documentary taxes or any other excise or property taxes,
charges or similar levies which arise from any payment made hereunder or from
the execution, delivery or registration of, or otherwise with respect to, this
Agreement or any Note (hereinafter referred to as "OTHER TAXES").

          (c) Indemnification for Taxes Paid by a Lender. The Borrower shall
indemnify each Lender, the L/C Issuer and the Swingline Lender for the full
amount of Taxes or Other Taxes (including, without limitation, any Taxes or
Other Taxes imposed by any jurisdiction on amounts payable under this Section
2.18(c) paid by any Lender, the L/C Issuer or the Swingline Lender) and any
liability (including penalties, interest and expenses) arising therefrom or with
respect thereto, whether or not such Taxes or Other Taxes were correctly or
legally asserted. This indemnification shall be made within 30 days from the
date a Lender, the L/C Issuer or the Swingline Lender makes written demand
therefor.

          (d) Certificate. Within 30 days after the date of any payment of any
Taxes or Other Taxes by the Borrower on behalf of a Lender, the L/C Issuer or
the Swingline Lender, the Borrower shall furnish to each Lender, the L/C Issuer
or the Swingline Lender, at its address referred to herein, the original or a
certified copy of a receipt evidencing payment thereof. If no Taxes are payable
in respect of any payment by the Borrower, the Borrower shall, if so requested
by a Lender, the L/C Issuer or the Swingline Lender, provide a certificate or an
officer of the Borrower to that effect.

          (e) Withholding. Any of (A) a Lender, (B) the L/C Issuer or (C) the
Swingline Lender that is not incorporated under the laws of the United States of
America or a state thereof agrees that it will deliver to the Borrower and the
Agent (i) two duly completed copies of United States Internal Revenue Service
Form 1001 or 4224 or successor applicable form, as the case may be (assuming
that it is entitled to do so), and (ii) two duly completed copies of Internal
Revenue Service Form W-8 or W-9 or successor applicable form. Each such Lender,
L/C Issuer and Swingline Lender also agrees to deliver to the Borrower and the
Agent two further copies of the said Form 1001 or 4224 and Form W-8 or W-9, or
successor applicable forms or other manner of certification, as the case may be,
on or before the date that any such form expires or becomes obsolete or
otherwise is required to be resubmitted as a condition to obtaining an exemption
from withholding tax or after the occurrence of any event requiring a change in
the most recent form previously delivered by it to the Borrower and the Agent,
and such extensions or renewals thereof as may reasonably be requested by the
Borrower or the Agent, unless in any such case an event (including, without
limitation, any change in treaty, law or regulation) has occurred prior to the
date on which any such delivery 

                                       38
<PAGE>
 
would otherwise be required which renders all such forms inapplicable or which
would prevent such Lender, L/C Issuer or Swingline Lender from duly completing
and delivering any such form with respect to it and such Lender, L/C Issuer or
Swingline Lender so advises the Borrower and the Agent. Such Lender, L/C Issuer
or Swingline Lender shall certify (i) in the case of Form 1001 or 4224, that it
is entitled to receive payments under this Agreement without deduction or
withholding of any United States federal income taxes (assuming that it is
entitled to do so) and (ii) in the case of Form W-8 or W-9, that it is entitled
to an exemption from United States backup withholding tax.

          2.19. Payments. All payments and prepayments to be made in respect of
principal, interest, Unreimbursed L/C Draws, Fees, or other amounts due from the
Borrower hereunder shall be payable prior to 11:00 A.M. (Pittsburgh,
Pennsylvania time) on the date when due without presentment, demand, protest or
notice of any kind, all of which are hereby expressly waived by the Borrower,
and without setoff, counterclaim or other deduction of any nature, and an action
therefor shall immediately accrue. Such payments shall be made to the Agent at
the Principal Office for the ratable account of the Lenders, the L/C Issuer or
the Swingline Lender, as the case may be, in Dollars and in immediately
available funds, and the Agent shall promptly distribute such amounts to the
Lenders, the L/C Issuer or the Swingline Lender, as the case may be, in
immediately available funds in accordance with the terms and provisions of
Section 9.10 of this Agreement. The Agent's, the L/C Issuer's, the Swingline
Lender's and each Lender's statement of account, ledger or other relevant record
shall, in the absence of manifest error, be conclusive as the statement of the
amount of principal of and interest on the Revolving Credit Loans, the Swingline
Loans, the Unreimbursed L/C Draws, Fees and other amounts owing under this
Agreement and shall be deemed an "account stated." Notwithstanding anything
herein to the contrary, (i) any administration or underwriting fee paid by the
Borrower to the Agent shall be solely for the account of the Agent, (ii) any L/C
Fronting Fees paid by the Borrower shall be solely for the account of the L/C
Issuer and (iii) any interest paid on any Unreimbursed L/C Draw to the extent a
Lender has not been required to honor or has not honored its funding obligations
pursuant to Section 2.17(g) hereof shall be solely for the account of the L/C
Issuer.

                                  ARTICLE III
                  LOAN DISBURSEMENT ACCOUNT, GUARANTEES, ETC.

        3.01. Loan Disbursement Account. The Borrower shall maintain at all
times during this Agreement with the Agent, at the Agent's office in Pittsburgh,
Pennsylvania, a demand deposit account (the "LOAN DISBURSEMENT ACCOUNT"), into
which proceeds of Revolving Credit Loans, Swingline Loans and other monies
transferred to the Borrower hereunder shall be deposited from time to time. The
Loan Disbursement Account shall be in the name of the Borrower and, subject to
the other provisions of this Agreement and the other Loan Documents, monies
therein shall be disbursed as directed by the Borrower, from time to time. To
secure the payment and performance of Lender Obligations, the Borrower hereby
pledges and assigns, and grants to the Agent for the benefit of the Agent, the
L/C Issuer, the Swingline Lender and the Lenders, a lien on and security
interest in the Loan Disbursement Account, all funds from time to time deposited
or held therein, all interest and other income derived therefrom, and all
proceeds of all the foregoing.

        3.02. Designation of Subsidiary Guarantors. Each Subsidiary of the
Borrower listed on Schedule 3.02 attached hereto together with each Subsidiary
of the Borrower incorporated or organized in the United States of America,
acquired, incorporated or formed 

                                       39
<PAGE>
 
after the date hereof shall be automatically designated as a Subsidiary
Guarantor by the Lenders. Any Subsidiary designated as a Subsidiary Guarantor
shall continue as a Subsidiary Guarantor until released in writing by all
Lenders.

  3.03. Further Cooperation. The Borrower shall perform, or cause each
Subsidiary Guarantor to perform, on the reasonable request of the Agent and at
the Borrower's expense, such reasonable acts as may be necessary or reasonably
advisable to carry out the intent of this Agreement and the other Loan
Documents. Without limiting the generality of the preceding sentence, the
Borrower shall cause each newly-created or acquired Subsidiary Guarantor to
execute and deliver a Subsidiary Guaranty to the Agent within a reasonable
period of time following the creation or acquisition of such Subsidiary
Guarantor.

                                   ARTICLE IV
                         REPRESENTATIONS AND WARRANTIES

  Representations and Warranties. The Borrower represents and warrants to the
Agent, each of the Lenders, the Swingline Lender and the L/C Issuer as follows:

  4.01. Organization and Qualification.

        (a) The Borrower is a corporation duly organized, validly existing and
in good standing under the laws of the Commonwealth of Pennsylvania, the
Borrower has the lawful power to own or lease its properties and to engage in
the business it presently conducts or proposes to conduct; and the Borrower is
duly licensed or qualified and in good standing in each jurisdiction listed on
Schedule 4.01 hereto and in all other jurisdictions where the property owned or
leased by it or the nature of the business transacted by it makes such licensing
or qualification necessary, except for those jurisdictions where the Borrower's
non-qualification would not cause there to be a Material Adverse Change.

        (b) Each Subsidiary Guarantor is a corporation, business trust or
limited partnership, as the case may be, duly organized, validly existing and in
good standing under the laws of the state of its incorporation or organization,
as the case may be, shown on Schedule 4.01; each Subsidiary Guarantor has the
lawful power to own or lease its properties and to engage in the business it
presently conducts or proposes to conduct; and each Subsidiary Guarantor is duly
licensed or qualified and in good standing in each jurisdiction listed on
Schedule 4.01 hereto and in all other jurisdictions where the property owned or
leased by it or the nature of the business transacted by it makes such licensing
or qualification necessary, except for those jurisdictions where such Subsidiary
Guarantor's non-qualification would not cause there to be a Material Adverse
Change.

  4.02.  Capitalization and Ownership. As of September 30, 1998, the authorized
capital stock of the Borrower consisted of 15,000,000 shares of common stock of
which 7,245,690 shares were issued and outstanding, and 3,000,000 shares of
preferred stock, of which no shares were issued and outstanding. All of the
capital stock of the Borrower has been validly issued and is fully paid and
nonassessable. Except as set forth in Schedule 4.02, there are no options,
warrants or other rights outstanding to purchase any such capital stock.

  4.03. Subsidiaries. Except for the Subsidiaries and investments in other
Persons set forth in Schedule 4.03, the Borrower does not own directly or
indirectly any capital stock of any other Person, is not a partner (general or
limited) of any partnership, is not a party 

                                       40
<PAGE>
 
to any joint venture and does not own (beneficially or of record) any equity
interest or similar interest in any other Person.

  4.04. Power and Authority. The Borrower and each Subsidiary Guarantor has full
power to enter into, execute, deliver, carry out and perform this Agreement and
the Loan Documents to which it is a party, to incur the Indebtedness
contemplated by the Loan Documents and to perform its obligations under the Loan
Documents to which it is a party and all such actions have been duly authorized
by all necessary corporate proceedings on its part.

  4.05. Validity and Binding Effect. This Agreement has been, and each Loan
Document, when executed and delivered by the Borrower and each Subsidiary
Guarantor, will have been, duly and validly executed and delivered by the
Borrower or such Subsidiary Guarantor. This Agreement and each of the other Loan
Documents executed and delivered by the Borrower and each Subsidiary Guarantor
will constitute legal, valid and binding obligations of the Borrower or such
Subsidiary Guarantor, enforceable against the Borrower or such Subsidiary
Guarantor in accordance with their respective terms, except to the extent that
enforceability of any of the Loan Documents may be limited by bankruptcy,
insolvency, reorganization, moratorium or other similar laws affecting the
enforceability of creditors' rights generally or limiting the right of specific
performance.

  4.06.  No Conflict.

         (a) Neither the execution and delivery by the Borrower of this
Agreement or the Loan Documents to which the Borrower is a party, nor the
consummation of the transactions herein or therein contemplated, nor compliance
with the terms and provisions hereof or thereof by the Borrower will (i)
conflict with, constitute a default under or result in any breach of (A) the
terms and conditions of the certificate of incorporation, by-laws or other
organizational documents of the Borrower or (B) any Law or any agreement or
instrument or order, writ, judgment, injunction or decree to which the Borrower
is a party or by which it is bound or to which it is subject, which conflict,
default or breach would cause a Material Adverse Change, or (ii) result in the
creation or enforcement of any Lien upon any property (now or hereafter
acquired) of the Borrower (other than the Permitted Liens).

         (b) Neither the execution and delivery by a Subsidiary Guarantor of a
Subsidiary Guaranty to which such Subsidiary Guarantor is a party, nor the
consummation of the transactions contemplated by this Agreement or the other
Loan Documents, nor compliance with the terms and provisions hereof or thereof
by such Subsidiary Guarantor will (i) conflict with, constitute a default under
or result in any breach of (A) the terms and conditions of the articles of
incorporation, by-laws or other organizational documents of such Subsidiary or
(B) any Law or any agreement or instrument or order, writ, judgment, injunction
or decree to which such Subsidiary is a party or by which it is bound or to
which it is subject, which conflict, default or breach would cause a Material
Adverse Change, or (ii) result in the creation or enforcement of any Lien upon
any property (now or hereafter acquired) of such Subsidiary (other than the
Permitted Liens).

  4.07. Litigation. Except for the litigation set forth on Schedule 4.07, there
are no actions, suits, proceedings or investigations pending or, to the
knowledge of the Borrower, threatened against the Borrower or any Subsidiary of
the Borrower, at law or in equity, before any Official Body which individually
or in the aggregate, if adversely determined, would be likely to result in any
Material Adverse Change. Neither the Borrower nor any Subsidiary of the

                                       41
<PAGE>
 
Borrower is in violation of any order, writ, injunction or decree of any
Official Body which could be expected to result in any Material Adverse Change.

  4.08.  Financial Statements.

         (i) Financial Statements. The Borrower has delivered to the Agent the
consolidated annual financial statements of the Borrower and its Subsidiaries
for the Fiscal Year ended December 31, 1997, and the consolidated quarterly
financial statements of the Borrower and its Subsidiaries for the Fiscal Quarter
ended September 30, 1998. All such financial statements are complete and correct
in all material respects and fairly present the consolidated financial condition
of the Borrower and its Subsidiaries in all material respects and the results of
their operations as of the dates and for the periods referred to, and have been
prepared in accordance with GAAP throughout the period included, consistently
applied.

         (ii) Accuracy of Financial Statements. The Borrower and its
Subsidiaries have no liabilities, contingent or otherwise, that are not
disclosed in the financial statements referred to in item (i) immediately above
and that would be required to be disclosed in accordance with GAAP, except for
those incurred since the date of such financial statements in the ordinary
course of business.

  4.09. Margin Stock; Section 20 Subsidiaries. Neither the Borrower nor any of
its Subsidiaries engage or intend to engage principally, or as one of its
important activities, in the business of incurring Indebtedness or extending
credit to others (including, without limitation, any of the Subsidiaries of the
Borrower) for the purpose, immediately, incidentally or ultimately, of
purchasing or carrying margin stock (within the meaning of any Margin
Regulation). No part of the proceeds of any Revolving Credit Loan or Swingline
Loan has been or will be used, immediately, incidentally or ultimately, to
purchase or carry any margin stock or to extend credit to others (including,
without limitation, any of its Subsidiaries) for the purpose of purchasing or
carrying any margin stock or to refund or retire Indebtedness originally
incurred for such purpose, or for any purpose which entails a violation of or
which is inconsistent with the provisions of the Margin Regulations of the Board
of Governors of the Federal Reserve System. The Borrower does not intend to
hold, and shall not permit its Subsidiaries to hold, margin stock. Neither the
Borrower not any of its Subsidiaries intends to use any portion of the proceeds
of the Loans, directly or indirectly, to purchase during the underwriting
period, or for thirty (30) days thereafter, Ineligible Securities being
underwritten by a Section 20 Subsidiary.

  4.10. Full Disclosure. Neither this Agreement nor any Loan nor any
certificate, statement, agreement or other document furnished to the Agent, the
L/C Issuer, the Swingline Lender or any Lender in connection herewith or
therewith, contains any misstatement of a material fact or omits to state a
material fact necessary in order to make the statements contained herein and
therein, in light of the circumstances under which they were made, not
misleading. There is no fact known to the Borrower which materially adversely
affects the business, property, assets, financial condition, results of
operations or prospects of the Borrower and its Subsidiaries, taken as a whole,
which has not been set forth in this Agreement or the Loan Documents or in the
certificates, statements, agreements or other documents furnished in writing to
the Agent, the Lenders, the L/C Issuer or the Swingline Lender prior to or at
the date hereof in connection with the transactions contemplated hereby and
thereby.

  4.11. Tax Returns and Payments. The Borrower is a member of an affiliated
group of companies which files consolidated federal tax returns. All such
federal tax returns that 

                                       42
<PAGE>
 
are required by law to be filed have been filed or properly extended. All taxes,
assessments and other governmental charges levied upon members of such
affiliated group or any of their respective properties, assets, income or
franchises which are due and payable have been paid in full other than (i) those
presently payable without penalty or interest, (ii) those which are being
contested in good faith by appropriate proceedings and (iii) those which, if not
paid, would not, in the aggregate, constitute a Material Adverse Change; and as
to each of items (i), (ii) and (iii) the affiliated group has established
reserves for such claim as have been determined to be adequate by application of
GAAP consistently applied. There are no agreements or waivers extending the
statutory period of limitations applicable to any consolidated federal income
tax return of the Borrower and its consolidated Subsidiaries for any period,
except as set forth on Schedule 4.11.

  4.12. Consents and Approvals. No consent, approval, exemption, order or
authorization of, or a registration or filing with any Official Body or any
other Person is required by any Law or any agreement in connection with the
execution, delivery and carrying out of this Agreement and the Loan Documents to
which the Borrower or any Subsidiary Guarantor is a party, except as listed on
Schedule 4.12 attached hereto, all of which items set forth on Schedule 4.12
shall have been obtained or made on or prior to the Closing Date.

  4.13. No Event of Default; Compliance with Instruments. No event has occurred
and is continuing and no condition exists or will exist after giving effect to
the borrowings to be made on the Closing Date under the Loan Documents which
constitutes an Event of Default or a Default. Neither the Borrower nor any of
its Subsidiaries is in violation of (i) any term of its certificate of
incorporation, by-laws or other organizational documents or (ii) any material
agreement or instrument to which it is a party or by which it or any of its
properties may be subject or bound where such violation would constitute a
Material Adverse Change.

  4.14. Compliance with Laws. The Borrower and its Subsidiaries are in
compliance in all material respects with all applicable Laws (other than
Environmental Laws, which are addressed in Section 4.20) in all jurisdictions in
which the Borrower, and its Subsidiaries, are presently or will be doing
business except where the failure to do so would not, individually or in the
aggregate, constitute a Material Adverse Change.

  4.15. Investment Company; Public Utility Holding Company. Neither the Borrower
nor any Subsidiary Guarantor is an "investment company" registered or required
to be registered under the Investment Company Act of 1940 or under the "control"
of an "investment company" as such terms are defined in the Investment Company
Act of 1940, as amended from time to time, and shall not become such an
"investment company" or under such "control. " Neither the Borrower nor any
Subsidiary Guarantor is a "holding company" or a "subsidiary company" of a
"holding company" or an "affiliate" of a "holding company" within the meaning
the Public Utility Holding Company Act of 1935, as amended from time to time.
The Borrower is not subject to any Law of any Official Body (in each case
whether United States federal, state or local, or other) having jurisdiction
over the Borrower, which purports to restrict or regulate its ability to borrow
money, or to extend or obtain credit, or to pledge its interests in the Loan
Disbursement Account. No Subsidiary Guarantor is subject to any Law of any
Official Body (in each case whether United States federal, state or local, or
other) having jurisdiction over such Subsidiary Guarantor which purports to
restrict or regulate its ability to borrow money or to extend or obtain credit.

                                       43
<PAGE>
 
  4.16. Plans and Benefit Arrangements. Except as set forth on Schedule 4.16
hereto:

        (i) The Borrower and each member of the ERISA Group are in compliance in
all material respects with any applicable provisions of ERISA with respect to
all Benefit Arrangements, Plans and Multiemployer Plans. There has been no
Prohibited Transaction with respect to any Benefit Arrangement or any Plan
(other than a Multiemployer Plan) or, to the knowledge of the Borrower, with
respect to any Multiemployer Plan or Multiple Employer Plan, which could result
in any material liability of the Borrower or any other member of the ERISA
Group. The Borrower and all members of the ERISA Group have made when due any
and all payments required to be made under any agreement relating to a
Multiemployer Plan or a Multiple Employer Plan or any Law pertaining thereto.
With respect to each Plan and, to the knowledge of Borrower, each Multiemployer
Plan, the Borrower and each member of the ERISA Group (i) have fulfilled in all
material respects their obligations under the minimum funding standards of
ERISA, (ii) have not incurred any liability to the PBGC (other than for premiums
not yet due) and (iii) have not had asserted against them any penalty for
failure to fulfill the minimum funding requirements of ERISA.

        (ii) To the best of the Borrower's knowledge, each Multiemployer Plan
and Multiple Employer Plan is able to pay benefits thereunder when due.

        (iii) No Termination Event has occurred or is reasonably anticipated to
occur with respect to any Plan which has resulted in or which will result in the
incurrence by the Borrower or any ERISA Affiliate of any liability to the PBGC
under Title IV of ERISA which has not been discharged or satisfied. No such
Termination Event is reasonably anticipated to occur which will result in a Lien
in favor of the PBGC against the property or rights to property of the Borrower
or any ERISA Affiliate.

        (iv) No event requiring notice to the PBGC under Section 302(f)(4)(A) of
ERISA has occurred or is reasonably expected to occur with respect to any Plan,
and no amendment with respect to which security is required under Section 307 of
ERISA has been made or is reasonably expected to be made to any Plan.

        (v) Neither the Borrower nor any other member of the ERISA Group has
incurred or reasonably expects to incur any material withdrawal liability under
ERISA to any Multiemployer Plan or Multiple Employer Plan. Neither the Borrower
nor any other member of the ERISA Group has been notified by any Multiemployer
Plan or Multiple Employer Plan that such Multiemployer Plan or Multiple Employer
Plan has been terminated within the meaning of Title IV of ERISA and, to the
knowledge of the Borrower, no Multiemployer Plan or Multiple Employer Plan is
reasonably expected to be reorganized or terminated, within the meaning of Title
IV of ERISA.

        (vi) To the extent that any Benefit Arrangement is insured, the Borrower
and all members of the ERISA Group have paid when due all premiums required to
be paid for all periods ending through and including the Closing Date. To the
extent that any Benefit Arrangement is funded other than with insurance, the
Borrower and all members of the ERISA Group have made when due all
contributions, to the extent required by applicable Law or the terms of such
Benefit Arrangement to be paid for all periods ending through and including the
Closing Date.

                                       44
<PAGE>
 
        4.17. Title to Properties. The Borrower and each of its Subsidiaries
have good title to, or a valid leasehold interest in, all their respective real
and personal property, except to the extent the failure to have such title or
leasehold interests is not reasonably likely, individually or in the aggregate,
to result in a Material Adverse Change, and none of such property is subject to
any Lien except Permitted Liens.

        4.18. Insurance. There are in full force and effect for the
benefit of the Borrower and its Subsidiaries insurance policies and bonds
providing adequate coverage from reputable and financially sound insurers in
amounts sufficient to insure the assets and risks of the Borrower and its
Subsidiaries in accordance with prudent business practice in the industry of the
Borrower and its Subsidiaries. No notice has been given or claim made and to the
knowledge of the Borrower, no grounds exist, to cancel or void any of such
policies or bonds or to reduce the coverage provided thereby.

        4.19. Employment Matters. The Borrower and each Subsidiary of the
Borrower are in compliance with all employee benefit plans, employment
agreements, collective bargaining agreements and labor contracts (the "LABOR
CONTRACTS") and all applicable federal, state and local labor and employment
Laws including, but not limited to, those related to equal employment
opportunity and affirmative action, labor relations, minimum wage, overtime,
child labor, medical insurance continuation, worker adjustment and relocation
notices, immigration controls and worker and unemployment compensation, except
where the failure to comply would not constitute a Material Adverse Change.
There are no outstanding grievances, arbitration awards or appeals therefrom
arising out of the Labor Contracts or current or, to the knowledge of the
Borrower, threatened strikes, picketing, handbilling or other work stoppages or
slowdowns at facilities of the Borrower or any Subsidiary of the Borrower which
in any case would constitute a Material Adverse Change. All payments due from
Borrower or any of its Subsidiaries on account of employee health and welfare
insurance which could reasonably be expected to have a Material Adverse Change
if not paid have been paid or accrued as a liability on the books of Borrower or
such Subsidiary.

        4.20. Environmental Matters. Except as disclosed on Schedule 4.20
hereto:

              (i) The Borrower has not received any Environmental Complaint from
any Official Body or private person alleging that the Borrower, any Subsidiary
of the Borrower or any prior or subsequent owner of any of the Property is a
potentially responsible party under the Comprehensive Environmental Response,
Cleanup and Liability Act, 42 U.S.C. (S)9601, et seq., in connection with the
Property which Environmental Complaint is reasonably expected to result in any
Material Adverse Change, and the Borrower has no reason to believe that such an
Environmental Complaint is reasonably likely to be received. There are no
pending or, to the knowledge of the Borrower, threatened Environmental
Complaints relating to the Borrower, any Subsidiary of the Borrower or, to the
Borrower's knowledge, without any inquiry, any prior or subsequent owner of the
Property pertaining to, or arising out of, any Environmental Conditions in
connection with the Property, which Environmental Complaints are reasonably
expected to result in any Material Adverse Change.

              (ii) Except for conditions, violations or failures which
individually and in the aggregate are not reasonably likely to result in a
Material Adverse Change, there are no circumstances at, on or under the Property
that constitute a breach of or non-compliance with any of the Environmental
Laws, and there are no past or present Environmental Conditions at,

                                       45
<PAGE>
 
on or under the Property or, to the knowledge of the Borrower, without any
inquiry at, on or under adjacent property, that prevent compliance with the
Environmental Laws at the Property.

        (iii) Neither the Property nor any structures, improvements, equipment,
fixtures, activities or facilities thereon or thereunder contain or use
Regulated Substances except in compliance with Environmental Laws, other than
such containment or use which individually and in the aggregate is not
reasonably likely to result in any Material Adverse Change. There are no
processes, facilities, operations, equipment or any other activities at, on or
under the Property, or, to the Borrower's knowledge, without any inquiry, at, on
or under adjacent property, that currently result in the release or threatened
release of Regulated Substances on to the Property in violation of the
Environmental Laws, except to the extent that such releases or threatened
releases are not likely to result in a Material Adverse Change.

        (iv) There are no underground storage tanks, or underground piping
associated with such tanks, used for the management of Regulated Substances at,
on or under the Property that are not in compliance with all Environmental Laws,
other than those with respect to which the failure to comply with Environmental
Laws is not reasonably likely, either individually or in the aggregate, to
result in a Material Adverse Change, and there are no abandoned underground
storage tanks or underground piping associated with such tanks, previously used
for the management of Regulated Substances at, on or under the Property that
have not been either abandoned in place, or removed, in accordance with the
Environmental Laws, other than those with respect to which the failure to comply
with Environmental Laws is not reasonably likely, either individually or in the
aggregate, to result in a Material Adverse Change.

        (v) The Borrower and each Subsidiary of the Borrower have all material
permits, licenses, authorizations and approvals necessary under the
Environmental Laws for the conduct of the respective businesses of the Borrower
and each Subsidiary of the Borrower as presently conducted, other than those
with respect to which the failure to comply with Environmental Laws is not
reasonably likely, either individually or in the aggregate, to result in a
Material Adverse Change. The Borrower and each Subsidiary of the Borrower have
submitted all notices, reports and other filings required by the Environmental
Laws to be submitted to an Official Body which pertain to past and current
operations on the Property, except for any failure to submit which would not be
reasonably likely to result in a Material Adverse Change.

        (vi) Except for violations which individually and in the aggregate are
not likely to result in a Material Adverse Change, all past and present on-site
generation, storage, processing, treatment, recycling, reclamation or disposal
of Solid Waste at, on, or under the Property and all off-site transportation,
storage, processing, treatment, recycling, reclamation or disposal of Solid
Waste has been done in accordance with the Environmental Laws.

        4.21. Senior Debt Status. The obligations of the Borrower under this
Agreement and the Notes rank at least pari passu in priority of payment with all
other Indebtedness of the Borrower, except Indebtedness of the Borrower to the
extent secured by Permitted Liens. The obligations of a Subsidiary Guarantor
under a Subsidiary Guaranty executed by such Subsidiary Guarantor rank at least
pari passu in priority of payment with all other Indebtedness of such Subsidiary
Guarantor except Indebtedness of such Subsidiary

                                       46
<PAGE>
 
Guarantor to the extent secured by Permitted Liens. There is no Lien upon or
with respect to any of the properties or income of the Borrower or any of its
Subsidiaries which secures Indebtedness or other obligations of any Person
except for Permitted Liens.

        4.22. Solvency. On the date hereof, and as of the date of each advance
of a Revolving Credit Loan or Swingline Loan and issuance or renewal of any
Letter of Credit, as the case may be, and after giving effect to such advance or
the issuance or renewal of a Letter of Credit, each of the Borrower and each
Subsidiary Guarantor is, and will be, Solvent.

        4.23. Material Contracts; Burdensome Restrictions. All material
contracts relating to the business operations of each Loan Party, including all
employee benefit plans and Labor Contracts, are valid, binding and enforceable
upon such Loan Party and each of the other parties thereto in accordance with
their respective terms, and there is no default thereunder with respect to such
Loan Party, and there is no default thereunder, to the Loan Parties' knowledge,
with respect to parties other than such Loan Party. No contract, lease,
agreement or other instrument to which the Borrower or any of its Subsidiaries
is a party or is bound and no provision of any applicable Law or governmental
regulation would reasonably be expected to have a Material Adverse Change.

        4.24. Patents, Trademarks, Copyrights, Licenses, Etc. The Borrower and
each of its Subsidiaries owns or possesses all the material patents, trademarks,
service marks, trade names, copyrights, licenses, registrations, franchises,
permits and rights necessary to own and operate its properties and to carry on
its business as presently conducted and planned to be conducted by the Borrower
or such Subsidiary, without, to the best of the Borrower's knowledge known
possible, alleged or actual conflict with the rights of others.

        4.25. Brokers. No broker or finder acting on behalf of the Borrower
brought about the obtaining, making or closing of the loans made pursuant to
this Agreement, and the Borrower has no obligation to any other Person in
respect of any finder's or brokerage fees in connection with the loans
contemplated by this Agreement.

        4.26. No Material Adverse Change. No event has occurred since September
30, 1998, and is continuing which has had or would reasonably be expected to
have a Material Adverse Change.

        4.27. Year 2000 Problem. The Borrower and its Subsidiaries have reviewed
areas within their business and operations which could be adversely affected by,
and have developed or are developing a program to address on a timely basis, the
risk that certain computer applications used by the Borrower or its Subsidiaries
(or, to the best of the Borrower's knowledge, any of their respective material
suppliers, customers or vendors) may be unable to recognize and perform properly
date-sensitive functions involving dates prior to and after December 31, 1999
(the "YEAR 2000 PROBLEM"). The Year 2000 Problem will not result in any Material
Adverse Change.

                                   ARTICLE V
             CONDITIONS OF LENDING OR ISSUANCE OF LETTER OF CREDIT

  The obligation of each Lender to make the Revolving Credit Loans hereunder, or
of the L/C Issuer to issue Letters of Credit hereunder, or of the Swingline
Lender to make Swingline Loans hereunder, is subject to the performance by the
Borrower of its obligations to 

                                       47
<PAGE>
 
be performed hereunder at or prior to the making of any such Revolving Credit
Loans or Swingline Loans, or the issuance of any such Letter of Credit, as the
case may be, and to the satisfaction of the following further conditions.

        5.01. Conditions to Initial Borrowings. On the Closing Date the
following actions shall be completed or satisfied to the sole satisfaction of
the Agent:

              (a) The representations and warranties of the Borrower or the
Subsidiaries contained in Article IV and in the other Loan Documents executed
and delivered by the Borrower or any of its Subsidiaries in connection with the
Closing shall be true and accurate in all material respects on and as of the
Closing Date with the same effect as though such representations and warranties
had been made on and as of such date (except representations and warranties
which relate solely to an earlier date or time, which representations and
warranties shall be true and correct on and as of the specific date or times
referred to therein), and the Borrower, and each Subsidiary of the Borrower
which has executed any Loan Documents, shall have performed, observed and
complied with all covenants and conditions hereof and contained in the other
Loan Documents; no Event of Default or Default under this Agreement shall have
occurred and be continuing or shall exist; no Material Adverse Change shall have
occurred; and there shall be delivered to the Agent, for the benefit of each
Lender, the L/C Issuer, the Swingline Lender and the Agent, a certificate of the
Borrower, dated the Closing Date and signed by the Chief Executive Officer and
President or Treasurer of the Borrower, to each such effect.

              (b) There shall be delivered to the Agent for the benefit of each
Lender, the L/C Issuer, the Swingline Lender and the Agent a certificate dated
the Closing Date and signed by the secretary or an assistant secretary of the
Borrower, certifying as appropriate as to:

                   (i) all corporate action taken by the Borrower in connection
with this Agreement and the other Loan Documents;

                   (ii) the names, offices and titles of the Borrower's officer
or officers authorized to sign this Agreement and the other Loan Documents and
the true signatures of such officer or officers and the identities of the
Authorized Officers permitted to act on behalf of the Borrower for purposes of
this Agreement and the other Loan Documents and the true signatures of such
officers, on which the Agent, each Lender, the L/C Issuer and the Swingline
Lender may conclusively rely;

                   (iii) (A) copies of the Borrower's organizational documents,
including its articles of incorporation as in effect on the Closing Date
certified by the Secretary of State of its incorporation as well as a copy of
the Borrower's by-laws, (B) a certificate as to the continued existence and good
standing of the Borrower issued by the Secretary of State of its incorporation,
and (C) a certificate concerning the due qualification of the Borrower as a
foreign corporation authorized to due business, and the good standing of the
Borrower, issued by the Secretary of State of each jurisdiction in which the
Borrower owns or leases Property;

                   (iv) all corporate or partnership action taken by each
Subsidiary Guarantor in connection with each Subsidiary Guaranty;

                                       48
<PAGE>
 
                      (v) the names, offices and titles of each Subsidiary
 Guarantor's officer or officers authorized to sign each Subsidiary Guaranty and
 the true signatures of such officer or officers and the identities of the
 Authorized Officers permitted to act on behalf of each Subsidiary Guarantor for
 purposes of each Subsidiary Guaranty and the true signatures of such officers,
 on which the Agent, each Lender, the L/C Issuer and the Swingline Lender may
 conclusively rely; and

                      (vi) (A) copies of each Subsidiary Guarantor's
organizational documents, as in effect on the Closing Date, certified, by the
secretary of state of the state of its organization, (B) a certificate as to the
continued existence and good standing of each Subsidiary Guarantor issued by the
secretary of state of the state of its organization, and (C) a certificate
concerning the due qualification of each Subsidiary Guarantor as a foreign
Person authorized to due business, and the good standing of such Subsidiary
Guarantor, issued by the Secretary of State of each jurisdiction in which such
Subsidiary Guarantor owns or leases Property.

          (c) This Agreement and the other Loan Documents required by the Agent
to be executed and delivered by the Borrower or a Subsidiary of the Borrower at
the Closing shall have been duly executed and delivered by the Borrower to the
Agent for the benefit of the Lenders, the L/C Issuer, the Swingline Lender and
the Agent.

          (d) There shall be delivered to the Agent for the benefit of each
Lender, the L/C Issuer, the Swingline Lender and the Agent written opinions of
Buchanan Ingersoll Professional Corporation and Thomas R. Lloyd, Esquire for the
Borrower and the Subsidiary Guarantors, dated the Closing Date and in form and
substance reasonably satisfactory to the Agent and its counsel as to the matters
set forth on Exhibits "E-1" and "E-2".

          (e) All legal details and proceedings in connection with the
transactions contemplated by this Agreement and the other Loan Documents shall
be in form and substance satisfactory to the Agent and its counsel, and the
Agent shall have received all such other counterpart originals or certified or
other copies of such documents and proceedings in connection with such
transactions, in form and substance reasonably satisfactory to the Agent and
said counsel, as the Agent or said counsel may reasonably request.

           (f) No Material Adverse Change shall have occurred since September
30, 1998, and no material litigation shall have been instituted by or against
the Borrower or any Subsidiary or any of their respective material properties or
assets; and there shall be delivered to the Agent for the benefit of each
Lender, the L/C Issuer, the Swingline Lender and the Agent a certificate of the
Borrower dated the Closing Date and signed by the Chief Executive Officer,
President or Chief Financial Officer of the Borrower to each such effect.

           (g) The Borrower shall deliver evidence acceptable to the Agent that
adequate insurance in compliance with Section 6.05 hereof is in full force and
effect.

           (h) All material consents required to effectuate the transactions
contemplated hereby as set forth on Schedule 4.12 shall have been obtained.

           (i) The making and/or assumption of any Loan or the issuance of a
Letter of Credit or assumption of any reimbursement liability with regard
thereto, shall not 

                                       49
<PAGE>
 
contravene any Law applicable to the Borrower, any Subsidiary Guarantor, the
Agent, the Lenders, the L/C Issuer or the Swingline Lender.

             (j) Except as set forth on Schedule 4.07, no action, suit,
proceeding, investigation, regulation or legislation shall have been instituted,
threatened or proposed before any court or other Official Body (i) with respect
to the Borrower or its Subsidiaries or this Agreement, the other Loan Documents
or the consummation of the transactions contemplated hereby or thereby to
enjoin, restrain or prohibit, or to obtain damages in respect of, their
performance under this Agreement or any other Loan Documents or the consummation
of the transactions contemplated hereby or thereby or (ii) which in the
reasonable opinion of Agent would have a Material Adverse Change.

             (k) The Agent shall have received evidence that the Prior Credit
Agreement has been terminated and all amounts due thereunder, except as
expressly assumed hereunder, have been paid in full.

             (l) The Agent on its own behalf and on behalf of the Lenders, the
L/C Issuer and the Swingline Lender shall be in receipt of all Fees due and
payable on or prior to the Closing Date and all reimbursable expenses incurred
on or prior to the Closing Date.

             (m) All matters and circumstances set forth as qualifications,
limitations, exceptions, additional matters or other materials set forth in the
Schedules hereto provided by or on behalf of the Borrower or its Subsidiaries
shall be acceptable to the Agent, the L/C Issuer, the Swingline Lender and the
Lenders in their reasonable discretion.

        5.02. Each Additional Revolving Credit Loan, Swingline Loan or
Issuance of a Letter of Credit. At the time of making any Revolving Credit
Loans or Swingline Loans or the issuance of, or renewal of, a Letter of Credit
and after giving effect to the proposed borrowings or issuance:

             (a) the representations and warranties of the Borrower contained in
Article IV hereof and in the other Loan Documents shall be true and correct in
all material respects on and as of the earlier of: (x) the date of such
additional Revolving Credit Loan or Swingline Loan or issuance of a Letter of
Credit or (y) the specific dates or times referred to therein, with the same
effect as though such representations and warranties have been made on and as of
such date;

             (b) the Borrower shall have performed and complied in all material
respects with all covenants and conditions hereof;

             (c) no Default or Event of Default shall have occurred and be
continuing or shall exist;

             (d) no material litigation shall have been instituted against the
Borrower or any Subsidiary or any of their respective materials properties or
assets;

             (e) no Material Adverse Change shall have occurred;

                                       50
<PAGE>
 
             (f) the making of any Loan or the issuance of any Letter of Credit
shall not contravene any Law applicable to the Borrower, the Agent, any of the
Lenders, the L/C Issuer or the Swingline Lender;

             (g) (A) For a Revolving Credit Loan the Borrower shall have
delivered to the Agent a duly executed and completed Loan Request, (B) for a
Swingline Loan the Borrower shall have complied with Section 2.13(c) hereof and
(C) with respect to the issuance of a Letter of Credit, the Borrower shall have
complied with the reasonable requirements of the L/C Issuer not inconsistent
with the terms hereof;

              (h) Total Utilization shall not exceed the aggregate Revolving
Credit Commitments; provided, however, that prior to the advance of any Loan on
a Borrowing Date the proceeds of which will repay any Unreimbursed L/C Draw, for
the purpose of calculating Total Utilization and compliance with this Subsection
5.02(f) on such date, the existing Total Utilization immediately prior to such
advance shall be reduced pro tanto by the dollar amount of the Loans to be
advanced on such Borrowing Date which will be used to repay any outstanding
Unreimbursed L/C Draws;

              (i) if the proceeds of the Loan are to be used to fund directly or
indirectly an acquisition, the following additional conditions need to be
satisfied:

                     (i) as to the relevant acquisition, each pre-condition to
the completion thereof, except payment due thereunder which has been completed;

                     (ii) certified copies of all corporate or partnership
action taken by the relevant Subsidiary Guarantor in connection with the
relevant Subsidiary Guaranty shall be delivered to the Agent;

                     (iii) the names, offices and titles of the relevant
Subsidiary Guarantor's officer or officers authorized to sign the relevant
Subsidiary Guaranty and the true signatures of such officer or officers and the
identities of the Authorized Officers permitted to act on behalf of the relevant
Subsidiary Guarantor for purposes of the relevant Subsidiary Guaranty and the
true signatures of such officers, on which the Agent, each Lender, the L/C
Issuer and the Swingline Lender may conclusively rely shall be delivered to the
Agent; and

                     (iv) (A) copies of the relevant Subsidiary Guarantor's
organizational documents, as in effect on the Closing Date, certified by the
secretary of state of the state of its organization, (B) a certificate as to the
continued existence and good standing of the relevant Subsidiary Guarantor
issued by the secretary of state of the state of its organization, and (C) a
certificate concerning the due qualification of the relevant Subsidiary
Guarantor as a foreign Person authorized to do business, and the good standing
of the relevant Subsidiary Guarantor issued by the secretary of state of each
jurisdiction where such qualification is material shall be delivered to the
Agent.

        5.03. Location of Closing. The Closing shall take place at 10:00 A.M.,
Pittsburgh, Pennsylvania time, on the Closing Date at the offices of Tucker
Arensberg, P.C., 1500 One PPG Place, Pittsburgh, Pennsylvania 15222, or at such
other time and place as the parties agree.

                                       51
<PAGE>
 
                                   ARTICLE VI
                             AFFIRMATIVE COVENANTS
                             ---------------------

  The Borrower covenants and agrees that, until payment in full of the Loans and
interest thereon, payment in full of all Letter of Credit reimbursement
obligations and interest thereon, satisfaction of all of the Borrower's other
obligations hereunder and termination of the Revolving Credit Commitments, and
the expiration and cancellation of all Letters of Credit issued hereunder, the
Borrower shall comply, or cause compliance, at all times with the affirmative
covenants set forth in Sections 6.01 through and including Section 6.14.

        6.01.   Preservation of Existence, Etc.

                (a) The Borrower shall maintain its corporate existence and its
license or qualification and its good standing in the state of its incorporation
and in each other jurisdiction in which its ownership or lease of property or
the nature of its businesses makes such license or qualification necessary
(except for such other jurisdictions in which such failure to be so licensed or
qualified individually and in the aggregate would not result in a Material
Adverse Change).

                (b) Each Subsidiary of the Borrower shall maintain its corporate
existence and its license or qualification and its good standing in the state of
its incorporation and in each other jurisdiction in which its ownership or lease
of property or the nature of its businesses makes such license or qualification
necessary (except for such other jurisdictions in which such failure to be so
licensed or qualified individually and in the aggregate would not result in a
Material Adverse Change).

        6.02. Accounting System; Reporting Requirements. The Borrower will
maintain, and will cause its Subsidiaries to maintain, a system of accounting
established and administered in accordance with GAAP, and will and will cause
its Subsidiaries to set aside on its books all such proper reserves as shall be
required by GAAP. Further, the Borrower will:

                (i) deliver to the Agent within forty-five (45) days after the
end of each of the first three (3) Fiscal Quarters in each Fiscal Year of the
Borrower, (A) consolidated balance sheet as at the end of such period for the
Borrower and its Subsidiaries, (B) consolidated statements of income for such
period for the Borrower and its Subsidiaries and, in the case of the second and
third quarterly periods, for the period from the beginning of the current Fiscal
Year to the end of such quarterly period, and (C) consolidated statements of
cash flow for such period for the Borrower and its Subsidiaries and, in the case
of the second and third quarterly periods, for the period from the beginning of
the current Fiscal Year to the end of such quarterly period; and each such
statement shall set forth, in comparative form, corresponding figures for the
corresponding period in the immediately preceding Fiscal Year; and all such
statements shall be prepared in reasonable detail and certified, subject to
changes resulting from year-end adjustments, by the Chief Executive Officer,
President or Treasurer of the Borrower;

                (ii) deliver to the Agent within 90 days after the end of each
Fiscal Year of the Borrower, (A) consolidated balance sheets as at the end of
such year for the Borrower and its Subsidiaries, (B) consolidated statements of
income for such year for the Borrower and its Subsidiaries, (C) consolidated
statements of cash flow for such year for the Borrower and its Subsidiaries, and
(D) consolidated statements of shareholders equity for such year for the
Borrower and its Subsidiaries; and each such statement shall set forth, in

                                       52
<PAGE>
 
comparative form, corresponding figures for the immediately preceding Fiscal
Year; and all such financial statements shall present fairly in all material
respects the financial position of the Borrower and its consolidated
Subsidiaries, as at the dates indicated and the results of its operations and
its cash flow for the periods indicated, in conformity with GAAP; and the
Borrower shall cause each of the consolidated financial statements described in
clauses (A) through (D) of this Section 6.02(ii) to be certified without
limitation as to scope or material qualification by Ernst & Young, LLP, or other
independent certified public accountants acceptable to the Required Lenders;

              (iii) deliver to the Agent, together with each delivery of
financial statements pursuant to items (i) and (ii) above, a Compliance
Certificate of the Borrower substantially in the form of Exhibit "D" hereto,
properly completed and signed by the Chief Executive Officer, President or
Treasurer of the Borrower, (A) stating (1) that such officer has reviewed the
terms of the Loan Documents and has made, or caused to be made under his
supervision, a review of the transactions and condition of the Borrower and its
Subsidiaries during the accounting period covered by such financial statements
and that such review has not disclosed the existence during such accounting
period, and (2) that the Borrower does not have knowledge of the existence, as
at the date of such Compliance Certificate, of any condition or event which
constitutes an Event of Default or a Default, or, if any such condition or event
existed or exists, specifying the nature and period of existence thereof and
what action the Borrower has taken or is taking or proposes to take with respect
thereto, and (B) demonstrating in reasonable detail compliance as at the end of
such accounting period with the restrictions contained in Section 7.12 hereof;

              (iv) within forty-five (45) days following the end of each Fiscal
Quarter, deliver to the Agent a report certified by an Authorized Officer
summarizing all contracts in progress of the Borrower, any operating division of
the Borrower or any Subsidiary, such summary to include, but not to be limited
to, schedules of completed jobs and aged contracts receivable, including
retention detail, all in such detail as is reasonably satisfactory to the Agent,
and containing such additional information as may be requested by the Agent from
time to time;

              (v) within ninety (90) days after the end of each Fiscal Year,
deliver to the Agent a budget for the upcoming Fiscal Year in such detail as the
Agent reasonably requests;

              (vi) promptly give written notice to the Agent of the happening of
any event (which is known to the Borrower) which constitutes an Event of Default
or a Default hereunder, but in no event shall any such notice be given later
than five (5) Business Days after the Borrower knows or should have known of
such event;

              (vii) promptly give written notice to the Agent of any pending or,
to the knowledge of the Borrower, overtly threatened claim in writing,
litigation or threat of litigation which arises between the Borrower, or any of
its Subsidiaries, and any other party or parties (including, without limitation,
any Official Body) which claim, litigation or threat of litigation, individually
or in the aggregate, is reasonably likely to cause a Material Adverse Change,
any such notice to be given not later than five (5) Business Days after any of
the Borrower becomes aware of the occurrence of any such claim, litigation or
threat of litigation;

              (viii) promptly deliver to the Agent, but in no event later than
ten (10) days after the Borrower, or any of its Subsidiaries, receives, copies
of (A) all reports, notices

                                       53
<PAGE>
 
and proxy statements sent by the Borrower to its shareholders, and (B) all
regular and periodic reports and definitive proxy materials (including but not
limited to Forms 10-K, 10-Q and 8-K) filed by the Borrower with any securities
exchange or the Federal Securities and Exchange Commission; and

                (ix) such other reports and information as the Agent or the
Required Lenders may from time to time reasonably request.

        6.03.  Notices Regarding Plans and Benefit Arrangements.

             (a) Promptly upon becoming aware of the occurrence thereof, notice
(including the nature of the event and, when known, any action taken or
threatened by the Internal Revenue Service or the PBGC with respect thereto)
shall be given to the Agent by the Borrower of:

                (i) any Reportable Event with respect to the Borrower or any
member of the ERISA Group,

                (ii) any Prohibited Transaction which could subject the Borrower
or any member of the ERISA Group to a civil penalty assessed pursuant to Section
502(i) of ERISA or a tax imposed by Section 4975 of the Internal Revenue Code in
connection with any Plan, Benefit Arrangement or any trust created thereunder,
if such tax and/or penalty is reasonably likely to result in a Material Adverse
Change,

                (iii) any assertion of material withdrawal liability with
respect to any Multiemployer Plan,

                (iv) any partial or complete withdrawal from a Multiemployer
Plan by the Borrower or any member of the ERISA Group under Title IV of ERISA
(or assertion thereof), where such withdrawal is likely to result in material
withdrawal liability,

                (v) any cessation of operations (by the Borrower of any member
or the ERISA Group) at a facility in the circumstances described in Section
4062(e) of ERISA,

                (vi) withdrawal by the Borrower or any member of the ERISA Group
from a Multiple Employer Plan,

                (vii) a failure by the Borrower or any member of the ERISA Group
to make a payment to a Plan required to avoid imposition of a lien under Section
302(f) of ERISA,

                (viii) the adoption of an amendment to a Plan requiring the
provision of security to such Plan pursuant to Section 307 of ERISA, or

                (ix) any change in the actuarial assumptions or funding methods
used for any Plan, where the effect of such change is to materially increase or
materially reduce the unfunded benefit liability or obligation to make periodic
contributions.

                                       54
<PAGE>
 
                (b) Promptly after receipt thereof, copies of (i) all notices
received by the Borrower or any member of the ERISA Group of the PBGC's intent
to terminate any Plan administered or maintained by the Borrower or any member
of the ERISA Group, or to have a trustee appointed to administer any such Plan;
and (ii) at the request of the Agent, the L/C Issuer, the Swingline Lender or
any Lender each annual report (IRS Form 5500 series) and all accompanying
schedules, the most recent actuarial reports, the most recent financial
information concerning the financial status of each Plan administered or
maintained by the Borrower or any member of the ERISA Group, and schedules
showing the amounts contributed to each such Plan by or on behalf of the
Borrower or any member of the ERISA Group in which any of their respective
personnel participate or from which such personnel may derive a benefit, and
each Schedule B (Actuarial Information) to the annual report filed by the
Borrower or any member of the ERISA Group with the Internal Revenue Service with
respect to each such Plan shall be given to the Agent by the Borrower.

                (c) Promptly upon the filing thereof, copies of any PBGC Form
200, 500, 600 or 601, or any successor form, filed with the PBGC in connection
with the termination of any Plan.

        6.04. Payment of Liabilities, Including Taxes, etc. The Borrower shall
duly pay and discharge, and shall cause its Subsidiaries to pay and discharge
all obligations, accounts, liabilities, taxes, assessments and governmental
charges and levies (subject, where applicable, to specified grace periods and,
in the case of trade payables, to normal payment practices), to which they are
subject or which are asserted against them, promptly as and when the same shall
become due and payable, including all taxes, assessments and governmental
charges upon them or any of their properties, assets, income or profits, prior
to the date on which penalties attach thereto; provided, however, the Borrower
may choose not to pay any such liabilities, including taxes, assessments or
charges, if the same are being contested in good faith and for which such
reserves (including reserves for any additional amounts which would be payable
as a result of the failure to discharge timely any such liabilities) or other
appropriate provisions, if any, as shall be required by GAAP shall have been
made.

        6.05. Maintenance of Insurance. The Borrower shall insure, and shall
cause its Subsidiaries to insure, their respective properties and assets against
loss or damage in such amounts as similar properties and assets are insured by
prudent companies in similar circumstances carrying on similar businesses, and
with reputable and financially sound insurers, including self-insurance to the
extent customary. The Borrower will furnish to the Agent on the Closing Date and
thereafter simultaneously with the delivery of the annual financial information
delivered pursuant to Section 6.02(ii) a certificate of the Borrower executed by
an Authorized Officer of the Borrower certifying that such insurance is in
force, is adequate in nature and amount and complies with the Borrower's
obligations under this Section 6.05.

        6.06. Maintenance of Properties and Leases. The Borrower and its
Subsidiaries shall maintain in good repair, working order and condition
(ordinary wear and tear excepted) in accordance with the general practice of
other businesses of similar character and size, all of those properties useful
or necessary to their respective businesses, and from time to time, the Borrower
will make or cause to be made all appropriate repairs, renewals or replacements
thereof.

        6.07. Maintenance of Permits and Franchises. The Borrower and its
Subsidiaries shall maintain in full force and effect all franchises, permits and
other 

                                       55
<PAGE>
 
authorizations necessary for the ownership and operation of their respective
properties and business if the failure so to maintain the same, individually or
in the aggregate, would constitute a Material Adverse Change.

        6.08. Visitation Rights. The Borrower shall permit, and
shall cause its Subsidiaries to permit, any of the officers or authorized
employees or representatives of the Agent or any of the Lenders to visit and
inspect any of the properties of the Borrower, or a Subsidiary of the Borrower,
and to examine and make excerpts from its books and records and discuss its
respective business affairs, finances and accounts with its officers, all in
such detail and at such times and as often as any of the Lenders may reasonably
request, provided that each Lender shall provide the Borrower, or the Subsidiary
of the Borrower, as the case may be, and the Agent with reasonable notice prior
to any visit or inspection and that only the Agent and its authorized employees
or representatives are permitted to conduct audits.

        6.09. Keeping of Records and Books of Account. The Borrower, and its
Subsidiaries, shall maintain and keep proper books of record and account which
enable the Borrower to issue financial statements in accordance with GAAP and as
otherwise required by applicable Laws of any Official Body having jurisdiction
over the Borrower and its Subsidiaries, and in which full, true and correct
entries shall be made in all material respects of all their respective dealings
and business and financial affairs.

        6.10. Plans and Benefit Arrangements. The Borrower shall, and shall
cause each member of the ERISA Group to, comply with ERISA, the Internal Revenue
Code and other applicable Laws applicable to Plans and Benefit Arrangements
except where such failure, alone or in conjunction with any other failure, would
not result in a Material Adverse Change. Without limiting the generality of the
foregoing, the Borrower shall cause all of its Plans and all Plans maintained by
any member of the ERISA Group to be funded in accordance with the minimum
funding requirements of ERISA and shall make, and cause each member of the ERISA
Group to make, in a timely manner, all contributions due to Plans, Benefit
Arrangements and Multiemployer Plans.

        6.11. Compliance with Laws. The Borrower and its Subsidiaries shall
comply with all applicable Laws (other than Environmental Laws) in all respects,
provided that they shall not be deemed to be a violation of this Section 6.11 if
any failure to comply with any Law would not result in fines, penalties, other
similar liabilities or injunctive relief which in the aggregate would constitute
a Material Adverse Change.

        6.12. Use of Proceeds. The Borrower will use the proceeds of the Loans
only for lawful purposes in accordance with Section 2.16 hereof as applicable
and such uses shall not contravene any applicable Law or any other provision
hereof. The Borrower will permit the use of the Letters of Credit only for
lawful purposes in accordance with Section 2.17 hereof as applicable, and such
uses shall not contravene any applicable Law or any other provision hereof. The
Borrower and its Subsidiaries shall not use any portion of the proceeds of the
Loans, directly or indirectly, to purchase during the underwriting period, or
for thirty (30) days thereafter, Ineligible Securities being underwritten by a
Section 20 Subsidiary.

        6.13.  Environmental Laws.

               (i) The Borrower and its Subsidiaries shall comply in all
material respects, subject to the disclosure set forth in Schedule 4.20, with
all Environmental Laws and 

                                       56
<PAGE>
 
shall obtain and comply in all material respects with and maintain any and all
licenses, approvals, registrations or permits required by Environmental Laws;

              (ii) The Borrower and its Subsidiaries shall conduct and complete
in all material respects all investigations, studies, sampling and testing, and
all remedial, removal and other actions required under Environmental Laws and
promptly comply in all material respects with all lawful orders and directives
of all Official Bodies respecting Environmental Laws, except to the extent that
the same are being contested in good faith by appropriate and lawful proceedings
diligently conducted and for which such reserves or other appropriate
provisions, if any, required by GAAP shall have been made; and

              (iii) The Borrower shall defend, indemnify and hold harmless the
Agent, the Lenders, the L/C Issuer and the Swingline Lender and their respective
employees, agents, officers and directors, from and against any claims, demands,
penalties, fines, liabilities, settlements, damages, costs and expenses of
whatever kind or nature known or unknown, contingent or otherwise, arising out
of, or in any way relating to the violation of or noncompliance with any
Environmental Laws applicable to the real property owned or operated by the
Borrower or any of its Subsidiaries, or any orders, requirements or demands of
any Official Bodies related thereto, including, without limitation, reasonable
attorney's and consultant's fees, investigation and laboratory fees, court costs
and litigation expenses, except to the extent that any of the foregoing arise
out of the gross negligence or willful misconduct of the party seeking
indemnification therefor.

        6.14. Senior Debt Status. The obligations of the Borrower under this
Agreement and the Notes will rank at least pari passu in priority of payment
with all other Indebtedness of the Borrower except Indebtedness of the Borrower
to the extent secured by Permitted Liens. The obligations of a Subsidiary
Guarantor under the Subsidiary Guaranty, executed by it will rank at least pari
passu in priority of payment with all other Indebtedness of such Subsidiary
Guarantor except Indebtedness of such Subsidiary Guarantor to the extent secured
by Permitted Liens.


                                  ARTICLE VII
                               NEGATIVE COVENANTS
                               ------------------

  The Borrower covenants and agrees that, until payment in full of the Loans and
interest thereon, payment in full of all Letter of Credit reimbursement
obligations and interest thereon, satisfaction of all of the Borrower's other
obligations hereunder and termination of the Revolving Credit Commitments, and
the expiration and cancellation of all Letters of Credit issued hereunder, the
Borrower shall comply, or cause the compliance, with the negative covenants set
forth in this Article VII.

        7.01. Indebtedness. The Borrower and its Subsidiaries shall not on a
consolidated basis at any time, create, incur, assume or suffer to exist any
Indebtedness (including Indebtedness secured by Permitted Liens), except:

              (i) Indebtedness under the Loan Documents;

              (ii) Existing Indebtedness as set forth on Schedule 7.01 hereto
(including any extensions or renewals thereof provided there is no increase in
the amount thereof or other significant change in the terms thereof);

                                       57
<PAGE>
 
             (iii) Indebtedness of a Subsidiary of the Borrower to the Borrower
or to another Subsidiary of the Borrower or the Indebtedness of the Borrower to
a Subsidiary of the Borrower;

             (iv) Indebtedness with respect to foreign exchange hedging
transactions entered into in the ordinary course of business to manage foreign
currency risk for the Borrower and/or one or more of its Subsidiaries;

             (v) Indebtedness incurred pursuant to Interest Hedge Agreements;
and

             (vi) Other Indebtedness not covered by items (i) through (v) above,
provided that the aggregate amount of such Indebtedness permitted by this item
(vi) shall not exceed $10,000,000 at any one time outstanding.

        7.02. Liens; Negative Pledge. The Borrower and its Subsidiaries shall
not at any time create, incur, assume or suffer to exist any Lien on any of
their respective property or assets, tangible or intangible, now owned or
hereafter acquired, or agree or become liable to do so, except Permitted Liens.
Further, neither the Borrower nor any of its Subsidiaries shall enter into any
agreement with any Person (other than the Agent, the L/C Issuer, the Swingline
Lender and the Lenders pursuant hereto) which prohibits or limits the ability of
the Borrower or any of its Subsidiaries to create, incur, assume or suffer to
exist any Lien upon any of its respective property, assets or revenues, whether
now owned or hereafter acquired.

        7.03. Loans, Acquisitions and Investments. The Borrower and its
Subsidiaries shall not at any time make any loan or advance to, or purchase or
otherwise acquire any stock, bonds, notes or securities of, or any partnership
interest (whether general or limited) or other equity interest in, or assets of,
or any other investment or interest in, or make any capital contribution to, any
other Person, or agree to or become liable to do any of the foregoing, except
for:

             (i) trade credit extended on usual and customary terms in the
ordinary course of business;

             (ii) fixed assets, equipment or inventory acquired in the ordinary
course of business;

             (iii) loans and advances to employees to meet expenses incurred by
such employees in the ordinary course of business, including without limitation
relocation expenses;

             (iv)  Cash Equivalents;

             (v) investments, capital contributions and advances by the
Borrower in existence as of the date hereof, which investments, capital
contributions and advances are set forth on Schedule 7.03 hereof;

             (vi) investments and capital contributions by the Borrower in, and
loans and advances by Borrower to, a third Person so long as after giving effect
to each such 

                                       58
<PAGE>
 
investment or capital contribution the Borrower shall not have caused a
violation of the Loan Documents;

             (vii) loans, advances and capital contributions by a Subsidiary of
the Borrower to the Borrower or any of the Borrower's other Subsidiaries or
loans, advances and capital contributions by the Borrower to any of its
Subsidiaries; and

             (viii)  the Borrower or any Subsidiary may acquire the assets or
voting securities of any other Person provided that (A) at the time of such
acquisition no Default or Event of Default shall have occurred and be continuing
or be caused by such acquisition, (B) the acquired Person, if any, shall become
a Subsidiary Guarantor simultaneously with such acquisition and shall execute
all Loan Documents required of a Subsidiary Guarantor, (C) the board of
directors or other equivalent governing body of such acquired Person shall have
approved such acquisition and, if the Borrower shall use any portion of the
Loans to fund such acquisition, the Borrower also shall have delivered to the
Agent written evidence of the approval of the board of directors (or equivalent
governing body) of such Person for such acquisition, and (D) the Borrower shall
have provided the Agent with a certificate stating that (i) such acquisition
will not violate any covenants of this Agreement and (ii) after giving effect to
such acquisition, the Consolidated Total Indebtedness to Consolidated EBITDA
Ratio shall not exceed 2.00 to 1.00; provided that this requirement shall not be
deemed to amend item (iii) of Section 7.12 hereof.

        7.04. Liquidations, Mergers and Consolidations. The Borrower shall not,
and shall not permit any Subsidiary of the Borrower to, dissolve, liquidate or
wind-up its affairs, or become a party to any merger, consolidation or other
business combination, whether accounted for under GAAP as a purchase or a
pooling of interests and regardless of whether the value of the consideration
paid or received is comprised of cash, common or preferred stock or other equity
interests, or other assets, or sell, lease, transfer, or otherwise dispose of
all or substantially all of its assets, provided that:

             (i) any Subsidiary of the Borrower may consolidate or merge into
the Borrower or another Subsidiary of the Borrower;

             (ii) any Subsidiary of the Borrower may sell, lease, transfer or
otherwise dispose of all or substantially all of its assets (upon voluntary
liquidation or otherwise) to the Borrower or another Subsidiary of the Borrower;
and

             (iii) the Borrower or any Subsidiary may consolidate or merge with
any Person, provided that (A) such Person must be engaged in businesses
substantially related to those of the Borrower or affected Subsidiary, (B) if
the Borrower is a party to such merger or consolidation, the Borrower is the
surviving Person, (C) at the time of the consolidation or merger no Default or
Event of Default shall have occurred and be continuing or be caused by such
consolidation or merger, (D) the surviving Person, if not the Borrower, shall
become a Subsidiary Guarantor, (E) the consolidation or merger shall not be
contested by such Person or the holders of its equity securities and shall be
approved by such Person's board of directors or other governing body and, if the
Borrower shall use any portion of the Loans to fund such consolidation or
merger, the Borrower also shall have delivered to the Agent written evidence of
the approval of the board of directors (or equivalent governing body) of such
Person for such consolidation or merger, and (F) the Borrower shall have
provided the Agent with a certificate stating that (i) such merger or
consolidation will not violate any covenants of this Agreement 

                                       59
<PAGE>
 
and (ii) after giving effect to such merger or consolidation, the Consolidated
Total Indebtedness to Consolidated EBITDA Ratio shall not exceed 2.00 to 1.00;
provided that this requirement shall not be deemed to amend item (iii) of
Section 7.12.

        7.05. Dispositions of Assets or Subsidiaries. Excluding the payment of
cash as consideration for assets purchased by, or services rendered to, the
Borrower or any Subsidiary, neither the Borrower nor any of its Subsidiaries
shall sell, convey, assign, lease, or otherwise transfer or dispose of,
voluntarily or involuntarily, any of its properties or assets, tangible or
intangible (including but not limited to sale, assignment, discount or other
disposition of receivables, contract rights, chattel paper, equipment or general
intangibles with or without recourse or of capital stock, shares or beneficial
interests or partnership interests in Subsidiaries), except:

              (i) any sale, transfer or disposition of surplus, obsolete or worn
out assets of the Borrower or a Subsidiary;

              (ii) any sale, transfer or lease of inventory by the Borrower or
any Subsidiary of the Borrower in the ordinary course of business;

              (iii) any sale, transfer or lease of assets by any Subsidiary of
the Borrower to the Borrower or any other Subsidiary of the Borrower or by the
Borrower to any Subsidiary of the Borrower; or

              (iv) any sale, transfer or lease of assets, other than those
specifically excepted pursuant to clauses (i) through (iii) above, which in any
one sale, transfer or lease of assets, or in any number of sales, transfers or
leases of assets occurring in any consecutive twelve month period, involves the
sale, transfer or lease of assets, the aggregate total proceeds of such sales
totaling not more than $10,000,000 (measured with respect to a series of sales,
transfers or leases of assets on the day of the first sale).

        7.06. Affiliate Transactions. Except as set forth on Schedule 4.02 and
as set forth on Schedule 7.06, neither the Borrower nor any Subsidiary of the
Borrower shall enter into or carry out any material transaction (including,
without limitation, purchasing property or services or selling property or
services) with an Affiliate which is not a Subsidiary unless such transaction is
not otherwise prohibited by this Agreement or the other Loan Documents, is
entered into in the ordinary course of business upon fair and reasonable arm's-
length terms and conditions which are fully disclosed to the Agent and is in
accordance with all applicable Law.

        7.07. Partnerships.   Except as permitted by Sections 7.01 and
7.03, neither the Borrower nor any Subsidiary of the Borrower shall become or
agree to become a general partner in any general or limited partnership or
otherwise become directly or indirectly liable for the obligations of another
Person without the consent of the Required Lenders, such consent not to be
unreasonably withheld.

        7.08. Continuation of or Change in Business. Neither the Borrower nor
any Subsidiary of the Borrower shall engage in any business other than the
business activities of such Persons substantially as conducted and operated by
the Borrower and its Subsidiaries on the Closing Date, and the Borrower shall
not permit any material change in such business.

                                       60
<PAGE>
 
        7.09. Plans and Benefit Arrangements. The Borrower shall not, and shall
not permit any member of the ERISA Group to:

             (i) fail to satisfy the minimum funding requirements of ERISA and
the Internal Revenue Code with respect to any Plan;

             (ii) request a minimum funding waiver from the Internal Revenue
Service with respect to any Plan;

             (iii) engage in a Prohibited Transaction with any Plan, Benefit
Arrangement or Multiemployer Plan which, alone or in conjunction with any other
circumstances or set of circumstances resulting in liability under ERISA, would
constitute a Material Adverse Change;

             (iv) fail to make when due any contribution to any Multiemployer
Plan that the Borrower or any member of the ERISA Group may be required to make
under any agreement relating to such Multiemployer Plan, or any Law pertaining
thereto;

             (v) withdraw (completely or partially) from any Multiemployer Plan
or be deemed under Section 4062(e) of ERISA to withdraw from any Multiple
Employer Plan, where any such withdrawal is likely to result in a material
liability of the Borrower or any member of the ERISA Group;

             (vi) terminate, or institute proceedings to terminate, any Plan,
where such termination is likely to result in a material liability to the
Borrower or any member of the ERISA Group;

             (vii) make any amendment to any Plan with respect to which security
is required under Section 307 of ERISA; or

             (viii) fail to give any and all notices and make all disclosures
and governmental filings required under ERISA or the Internal Revenue Code,
where such failure is likely to result in a Material Adverse Change.

        7.10. Fiscal Year. Neither the Borrower nor any Subsidiary of the
Borrower shall change its Fiscal Year from a period beginning January 1 and
ending on the immediately succeeding December 31.

        7.11. Changes in Organizational Documents. The Borrower shall not, and
shall not permit any Subsidiary Guarantor of the Borrower to, amend in any
respect its certificate or articles of incorporation without providing at least
thirty (30) calendar days' prior written notice to the Agent and the Lenders
and, in the event such change would be materially adverse to the Agent, the L/C
Issuer, the Swingline Lender or the Lenders as determined by the Agent in its
sole but reasonable discretion, obtaining the prior written consent of the
Required Lenders.

        7.12. Financial Covenants.

             (i) Minimum Consolidated Tangible Net Worth. The Borrower will not
at any time permit its Consolidated Tangible Net Worth to be less than an amount
equal to the sum of (i) $115,674,000, plus (ii) 50% of the positive net income
for each Fiscal Quarter ending 

                                       61
<PAGE>
 
after September 30, 1998, of the Borrower and its Subsidiaries determined on a
consolidated basis in accordance with GAAP consistently applied, plus (iii) an
amount equal to 100% of the net proceeds from the issuance by the Borrower after
December 31, 1998, of additional equity securities or other equity capital
investments.

             (ii) Current Ratio. As of the last day of each Fiscal Quarter, the
Borrower shall not permit its Current Ratio to be less than 1.6 to 1.0.

             (iii) Leverage Ratio. As of the last day of each Fiscal Quarter,
the Borrower shall not permit its Consolidated Total Indebtedness to
Consolidated EBITDA Ratio to exceed 3.0 to 1.0.

        7.13 Operating Leases. The Borrower and its Subsidiaries may not incur
operating leases which in the aggregate require rental payments in a Fiscal Year
to exceed $3,000,000.

        7.14 Stock Repurchase. During the term hereof, repurchase, as valued at
the purchase price therefor, more than $30,000,000 of its issued and outstanding
capital stock.

                                  ARTICLE VIII
                                    DEFAULT
                                    -------

        8.01. Events of Default. An "EVENT OF DEFAULT" shall mean the occurrence
or existence of any one or more of the following events or conditions (whatever
the reason therefor and whether voluntary, involuntary or effected by operation
of Law):

             (a) (i) The Borrower shall fail to pay any principal of any Loan
(including scheduled installments, mandatory prepayments or the payment due at
maturity, whether by acceleration or otherwise) when due, or (ii) the Borrower
shall fail to pay any Unreimbursed L/C Draw when due, or (iii) the Borrower
shall fail to pay any interest on any Loan, any Unreimbursed L/C Draw, any Fee,
or any other amount owing hereunder or under any other Loan Documents after such
interest, Fee or other amount becomes due in accordance with the terms hereof or
thereof and such failure shall continue for a period of five (5) days;

             (b) Any representation or warranty made at any time by the Borrower
herein or in any other Loan Document or by a Subsidiary Guarantor in any Loan
Document executed by such Subsidiary Guarantor, or in any certificate, other
instrument or statement furnished pursuant to the provisions hereof or thereof,
shall prove to have been false or misleading in any material respect as of the
time it was made or furnished;

             (c) The Borrower shall default in the observance or performance of
any covenant contained in Sections 6.13 or 6.14 or Article VII hereof;

             (d) The Borrower shall default in the observance or performance of
any other covenant, condition or provision hereof, or of any other Loan Document
and, if remediable, such default shall continue unremedied for a period of
thirty (30) days after any officer of the Borrower becomes aware of the
occurrence thereof; or a Subsidiary Guarantor shall default in the observance or
performance of any other covenant, condition or provision contained in a
Subsidiary Guaranty or any other Loan Document executed by such Subsidiary

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Guarantor, and such default shall continue unremedied for a period of thirty
(30) days after any officer of such Subsidiary Guarantor becomes aware of the
occurrence thereof;

                (e) A default or event of default shall occur at any time under
the terms of any agreements involving Indebtedness under which the Borrower or
any Subsidiary of the Borrower may be obligated as borrower, guarantor or
otherwise in excess of One Million Dollars ($1,000,000) in the aggregate, and
such breach, default or event of default consists of the failure to pay (beyond
any period of grace permitted with respect thereto, whether waived or not) any
Indebtedness when due (whether at stated maturity, by acceleration or otherwise)
or if such breach or default causes the acceleration of any such Indebtedness or
such breach or default permits the acceleration of any Indebtedness;

                (f) Any judgments or orders for the payment of money in excess
of One Million Dollars ($1,000,000) in the aggregate shall be entered against
the Borrower or any of its Subsidiaries, by a court having jurisdiction in the
premises which judgments are not satisfied, discharged, vacated, bonded or
stayed pending appeal within a period of thirty (30) days from the respective
date of entry;

                (g) Any of the Loan Documents shall cease to be legal, valid and
binding agreements enforceable against the party executing the same or such
party's successors and assigns (as permitted under the Loan Documents) in
accordance with the respective terms thereof (except to the extent that
enforceability of any of the Loan Documents may be limited by bankruptcy,
insolvency, reorganization, moratorium or other similar laws affecting the
enforceability of creditors' rights generally or limiting the right of specific
performance) or shall in any way be terminated (except in accordance with terms)
or become or be declared ineffective or inoperative or shall in any way be
challenged or contested or cease to give or provide the respective rights,
titles, interests, remedies, powers or privileges intended to be created thereby
in all material respects;

                (h) A notice of lien, levy or assessment in excess of One
Million Dollars ($1,000,000) in the aggregate is filed of record with respect to
all or any part of the assets of the Borrower or a Subsidiary Guarantor by the
United States, or any department, agency or instrumentality thereof, or by any
state, county, municipal or other governmental agency, including, without
limitation, the PBGC, or if any taxes or debts in excess of One Million Dollars
($1,000,000) owing at any time or times hereafter to any one of these becomes
payable and the same is not paid within thirty (30) days after the same becomes
payable, or if such notice is filed or such payment is not so made, unless the
Borrower or such Subsidiary Guarantor (i) contests such lien, assessment, tax or
debt in good faith by appropriate and lawful proceedings diligently conducted
but only so long as such proceedings could not subject the Agent, the Lenders,
the L/C Issuer or the Swingline Lender to any criminal penalties, (ii)
establishes such reserves or other appropriate provisions, if any, as shall be
required by GAAP and (iii) pays such Lien, assessment, tax or debt in accordance
with the terms of any final judgments or orders relating thereto within thirty
(30) days after the entry of such judgments or orders;

                (i) The Borrower or a Subsidiary Guarantor ceases to be Solvent
or admits in writing its inability to pay debts as they mature;

                (j) Any of the following occurs: (i) any Reportable Event, which
constitutes grounds for the termination of any Plan by the PBGC or the
appointment of a trustee 

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to administer or liquidate any Plan, shall have occurred and be continuing; (ii)
proceedings shall have been instituted or other action taken to terminate any
Plan, or a termination notice shall have been filed with respect to any Plan;
(iii) a trustee shall be appointed to administer or liquidate any Plan; (iv) the
PBGC shall give notice of its intent to institute proceedings to terminate any
Plan or Plans or to appoint a trustee to administer or liquidate any Plan and,
in the case of the occurrence of (i), (ii), (iii) or (iv) of this Section
8.01(j), the amount of Borrower's liability or the liability of the other
members of the ERISA Group is likely to exceed five percent (5%) of the
Consolidated Tangible Net Worth; (v) the Borrower or any member of the ERISA
Group shall fail to make any contributions when due to a Plan or a Multiemployer
Plan; (vi) the Borrower or any member of the ERISA Group shall make any
amendment to a Plan with respect to which security is required under Section 307
of ERISA; (vii) the Borrower or any member of the ERISA Group shall withdraw
completely or partially from a Multiemployer Plan; (viii) the Borrower or any
member of the ERISA Group shall withdraw (or shall be treated under Section
4062(e) of ERISA as having withdrawn) from a Multiple Employer Plan; or (ix) any
applicable Law is adopted, changed or interpreted by any Official Body with
respect to or otherwise affecting one or more Plans, Multiemployer Plans or
Benefit Arrangements and, with respect to any of the events specified in (v),
(vi), (vii), (viii) or (ix), any such occurrence would be reasonably likely to
materially and adversely affect the total enterprise represented by the Borrower
and the other members of the ERISA Group;

        (k) The Borrower or a Subsidiary Guarantor is enjoined, restrained or in
any way prevented by court order from conducting all or any material part of its
business and such injunction, restraint or other preventive order is not stayed
or dismissed within thirty (30) days after the entry thereof;

        (l) (i) any person or group of persons (within the meaning of Sections
13(g) or 14(d)(2) of the Securities Exchange Act of 1934, as amended), other
than Mr. W. R. Jackson or his Affiliates, shall have acquired beneficial
ownership of (within the meaning of Rule 13d-3 promulgated by the Securities and
Exchange Commission under said Act) 30% or more of the voting capital stock of
the Borrower;

            (ii) within a period of twelve (12) consecutive months, individuals
who were directors of the Borrower on the first day of such period and/or
individuals who become directors of the Borrower pursuant to a nomination or
election that was recommended or approved by the individuals who were directors
on the first day of such period shall cease to constitute a majority of the
board of directors of the Borrower; or

            (iii) the Borrower or a Subsidiary shall own less than 80% of the
voting capital stock or voting partnership or other equity interest of any
Subsidiary Guarantor;

        (m) A proceeding shall have been instituted in a court having
jurisdiction in the premises seeking a decree or order for relief in respect of
the Borrower, or a Subsidiary Guarantor, in an involuntary case under any
applicable bankruptcy, insolvency, reorganization or other similar law now or
hereafter in effect, or a receiver, liquidator, assignee, custodian, trustee,
sequestrator, conservator (or similar official) of the Borrower, or a Subsidiary
Guarantor, for any substantial part of such Person's property, or for the
winding-up or liquidation of such Person's affairs, and such proceeding shall
remain undismissed or unstayed and in effect for a period of thirty (30)
consecutive days or such court shall enter a decree or order granting any of the
relief sought in such proceeding;

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<PAGE>
 
        (n) The Borrower, or a Subsidiary Guarantor, shall commence a voluntary
case under any applicable bankruptcy, insolvency, reorganization or other
similar law now or hereafter in effect, shall consent to the entry of an order
for relief in an involuntary case under any such law, or shall consent to the
appointment or taking possession by a receiver, liquidator, assignee, custodian,
trustee, sequestrator, conservator (or other similar official) of itself or for
any substantial part of property or shall make a general assignment for the
benefit of creditors, or shall fail generally to pay debts as they become due,
or shall take any action in furtherance of any of the foregoing;

        (o) any of the Loan Documents shall cease to be in full force and effect
or shall be declared to be null and void by a court of competent jurisdiction;
or

        (p) any garnishment proceeding concerning a sum in excess of One Million
Dollars ($1,000,000) shall be instituted by attachment, levy or otherwise,
against any deposit account maintained by the Borrower or a Subsidiary Guarantor
with the Agent, the L/C Issuer, the Swingline Lender or any Lender; provided,
however, such garnishment shall not be deemed to be an Event of Default if the
Borrower has bonded for the potential loss of such deposit account with a
bonding company and on such terms acceptable to the Agent in its sole
discretion.

   8.02.  Consequences of Event of Default.

        (a) If an Event of Default specified in any of items (a) through (l) or
item (o) or (p) of Section 8.01 hereof shall occur and be continuing, the
Lenders shall be under no further obligation to make Revolving Credit Loans
hereunder, the L/C Issuer shall be under no further obligation to issue or amend
Letters of Credit hereunder, the Swingline Lender shall be under no further
obligation to make Swingline Loans hereunder, and the Agent may, and upon the
request of the Required Lenders shall, by written notice to the Borrower,
terminate the Revolving Credit Commitment and declare the unpaid principal
amount of the Notes then outstanding and all interest accrued thereon, any
unpaid fees and all other Indebtedness of the Borrower to the Lenders, the
Agent, the L/C Issuer or the Swingline Lender hereunder and under the other Loan
Documents to be forthwith due and payable, and the same shall thereupon become
and be immediately due and payable to the Agent for the benefit of each Lender,
the Agent, the L/C Issuer and the Swingline Lender without presentment, demand,
protest or any other notice of any kind, all of which are hereby expressly
waived; and

        (b) If any Event of Default specified in item (m) or (n) of Section 8.01
hereof shall occur, the Lenders shall be under no further obligations to make
Revolving Credit Loans hereunder, the L/C Issuer shall be under no further
obligation to issue or amend Letters of Credit hereunder, the L/C Issuer shall
be under no further obligation to issue or amend Letters of Credit hereunder,
the Swingline Lender shall be under no further obligation to make Swingline
Loans hereunder, the Revolving Credit Commitment shall be terminated and the
unpaid principal amount of the Notes then outstanding and all interest accrued
thereon, any unpaid fees and all other Indebtedness of the Borrower to the
Lenders, the Agent, the L/C Issuer and the Swingline Lender hereunder and under
the other Loan Documents shall be immediately due and payable, without
presentment, demand, protest or notice of any kind, all of which are hereby
expressly waived; further, during the thirty (30) day period referred to in item
(m) the Lenders shall be under no further obligation to make Revolving Credit
Loans, the L/C
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Issuer shall be under no further obligation to issue or amend Letters of Credit
hereunder, the Swingline Lender shall be under no further obligation to make
Swingline Loans hereunder; and

                (c) If an Event of Default shall occur and be continuing, any
Lender, the Agent or the L/C Issuer to whom any obligation is owed by the
Borrower hereunder or under any other Loan Document, of such Lender, Agent, L/C
Issuer or Swingline Lender and any branch, subsidiary or affiliate of such
Lender, Agent, L/C Issuer or Swingline Lender anywhere in the world shall each
have the right, in addition to all other rights and remedies available to it,
without notice to the Borrower, to set-off against and apply to the then unpaid
balance of all the Loans and all other obligations of the Borrower hereunder or
under any other Loan Document, any debt owing to, and any other funds held in
any manner for the account of, the Borrower by such Lender, Agent, L/C Issuer or
Swingline Lender or by such branch, subsidiary or affiliate, including, without
limitation, all funds in all deposit accounts (whether time or demand, general
or special, provisionally credited or finally credited, or otherwise) now or
hereafter maintained by the Borrower for its own account (but not including
funds held in custodian or trust accounts) with such Lender, Agent, L/C Issuer
or Swingline Lender or such branch, subsidiary or affiliate. Such right shall
exist in each case whether or not any Lender, the Agent, the L/C Issuer or the
Swingline Lender shall have made any demand under this Agreement or any other
Loan Document, whether or not such debt owing to or funds held for the account
of the Borrower is or are matured or unmatured and regardless of the existence
or adequacy of any other security, right or remedy available to any Lender, the
Agent, the L/C Issuer or the Swingline Lender; and

                (d) In addition to all of the rights and remedies contained in
this Agreement or in any of the other Loan Documents, the Agent, the L/C Issuer,
the Swingline Lender and the Lenders shall have all of the rights and remedies
of a creditor under applicable Law, all of which rights and remedies shall be
cumulative and non-exclusive, to the extent permitted by Law. The Agent may, and
upon the request of the Required Lenders shall, exercise all post-default rights
granted to the Agent, the L/C Issuer, the Swingline Lender and the Lenders under
the Loan Documents or applicable Law; and

                (e) Upon the occurrence of any Event of Default described in the
foregoing Sections 8.01(m) or (n) or upon the declaration by the Required
Lenders of any other Event of Default and the termination of the Revolving
Credit Commitments, the obligation of the L/C Issuer to issue or amend Letters
of Credit shall terminate, the L/C Issuer or the Agent may provide written
demand to any beneficiary of a Letter of Credit to present a draft against such
Letter of Credit, and an amount equal to the maximum amount which may at any
time be drawn under the Letters of Credit then outstanding (whether or not any
beneficiary of such Letters of Credit shall have presented, or shall be entitled
at such time to present, the drafts or other documents required to draw under
the Letters of Credit) shall automatically become immediately due and payable,
without presentment, demand, protest or other requirements of any kind, all of
which are hereby expressly waived by the Borrower; provided that the foregoing
shall not affect in any way the obligations of the Lenders to purchase from the
L/C Issuer participations in the unreimbursed amount of any drawings under the
Letters of Credit as provided in Section 2.17(c). So long as the Letters of
Credit shall remain outstanding, any amounts declared due pursuant to this
Section 8.02(e) with respect to the outstanding Letters of Credit when received
by the Agent shall be deposited and held by the Agent in an interest bearing
account denominated in the name of the Agent for the benefit of the Agent, the
Lenders and the L/C Issuer over which the Agent shall have sole dominion and
control of withdrawals (the "CASH COLLATERAL ACCOUNT") as cash collateral for
the obligation of the Borrower to reimburse the L/C Issuer in the event of any
drawing under the Letters of Credit and upon any 

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<PAGE>
 
drawing under such Letters of Credit in respect of which the Agent has deposited
in the Cash Collateral Account any amounts declared due pursuant to this Section
8.02(e), the Agent shall apply such amounts held by the Agent to reimburse the
L/C Issuer for the amount of such drawing. In the event that any Letter of
Credit in respect of which the Agent has deposited in the Cash Collateral
Account any amounts described above is cancelled or expires or in the event of
any reduction in the maximum amount available at any time for drawing under the
Letters of Credit outstanding, the Agent shall apply the amount then in the Cash
Collateral Account designated to reimburse the L/C Issuer for any drawings under
the Letters of Credit less the maximum amount available at any time for drawing
under the Letters of Credit outstanding immediately after such cancellation,
expiration or reduction, if any, to the payment in full of the outstanding
Lender Obligations, and second, to the payment of any excess, to the Borrower.

                                   ARTICLE IX
                                   THE AGENT
                                   ---------

        9.01. Appointment and Grant of Authority. Each of the Lenders, the L/C
Issuer and the Swingline Lender hereby appoints PNC Bank, National Association,
and PNC Bank, National Association, hereby agrees to act, as the Agent under
this Agreement and the other Loan Documents. The Agent shall have and may
exercise such powers under this Agreement and the other Loan Documents as are
specifically delegated to it by the terms hereof or thereof, together with such
other powers as are incidental thereto. Without limiting the foregoing, the
Agent, on behalf of the Lenders, the L/C Issuer and the Swingline Lender, is
authorized to execute all of the Loan Documents (other than this Agreement) and
to accept all of the Loan Documents and all other agreements, documents or
instruments reasonably required to carry out the intent of the parties to this
Agreement.

        9.02. Delegation of Duties. The Agent may perform any of its duties
hereunder by or through agents or employees (provided such delegation does not
constitute a relinquishment of duties as the Agent hereunder) and, subject to
Sections 9.07 and 10.03 hereof, shall be entitled to engage and pay for the
advice or services of any attorneys, accountants, or other experts concerning
all matters pertaining to duties hereunder and to rely upon any advice so
obtained.

        9.03. Reliance by Agent on Lenders for Funding. Unless the Agent shall
have received notice from a Lender prior to any Borrowing Date that such Lender
will not make available to the Agent such Lender's portion of net disbursements
of Revolving Credit Loans, the Agent may assume that such Lender has made such
portion available to the Agent and the Agent may, in reliance upon such
assumption, make Revolving Credit Loans to the Borrower. The Agent may, in
reliance upon such assumption (but shall not be required to) make available to
the Borrower a corresponding amount. If such corresponding amount is not made
available to the Agent by such Lender, the Agent shall be entitled to recover
such amount on demand from such Lender (or, if such Lender fails to pay such
amount forthwith upon demand from the Borrower) 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 the date the Agent recovers such
amount, at a rate per annum equal to (i) the Federal Funds Effective Rate during
the first three (3) days after interest shall begin to accrue and (ii) the
applicable interest rate in respect of such Revolving Credit Loan after the end
of such three-day period. The failure by any Lender to pay its portion of a
Revolving Credit Loan made by the Agent shall not relieve any other Lender of
the obligation to pay its portion of net disbursements of Revolving Credit Loans

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<PAGE>
 
on any Borrowing Date, but no Lender shall be responsible for the failure of any
other Lender to make its net share of Revolving Credit Loans to be made by such
other Lender on such Borrowing Date.

        9.04. Non-Reliance on Agent. Each Lender, the L/C Issuer and the
Swingline Lender agree that (i) it has, independently and without reliance on
the Agent, and based on such documents and information as it has deemed
appropriate, made its own credit analysis of the Borrower and its Subsidiaries
and decision to enter into this Agreement and (ii) that it will, independently
and without reliance upon the Agent, and based on such documents and information
as it shall deem appropriate at the time, continue to make its own analysis and
decisions in taking or not taking action under this Agreement. Except as
otherwise provided herein or under any other Loan Document, the Agent shall not
have any duty to keep the Lenders, the L/C Issuer or the Swingline Lender
informed as to the performance or observance by the Borrower of this Agreement
or any other document referred to or provided for herein or to inspect the
properties or books of the Borrower or any of its Subsidiaries. The Agent, in
the absence of gross negligence or willful misconduct, shall not be liable to
any Lender, the L/C Issuer or the Swingline Lender for their failure to relay or
furnish to the Lender, the L/C Issuer or the Swingline Lender any information.

        9.05. Responsibility of Agent and Other Matters.

             (a) Ministerial Nature of Duties. As between the Lenders, the L/C
Issuer, the Swingline Lender and itself, the Agent shall not have any duties or
responsibilities except those expressly set forth in this Agreement or in the
other Loan Documents, and those duties and responsibilities shall be subject to
the limitations and qualifications set forth in this Article IX. The duties of
the Agent shall be ministerial and administrative in nature.

             (b) Limitation of Liability. As between the Lenders, the L/C
Issuer, the Swingline Lender and the Agent, neither the Agent nor any of its
directors, officers, employees or agents shall be liable, in the absence of
gross negligence or willful misconduct, for any action taken or omitted (whether
or not such action taken or omitted is within or without the Agent's
responsibilities and duties expressly set forth in this Agreement) under or in
connection with this Agreement or any other instrument or document in connection
herewith. Without limiting the foregoing, neither the Agent nor any of its
directors, officers, employees or its agents, shall be responsible for, or have
any duty to examine (i) the genuineness, execution, validity, effectiveness,
enforceability, value or sufficiency of (A) this Agreement or any of the other
Loan Documents or (B) any other document or instrument furnished pursuant to or
in connection with this Agreement, (ii) the collectability of any amounts owed
by the Borrower to the Agent, the Lenders, the L/C Issuer or the Swingline
Lender, (iii) the truthfulness of any recitals or statements or representations
or warranties made to the Agent, the L/C Issuer, the Swingline Lender or the
Lenders in connection with this Agreement, (iv) any failure of any party to this
Agreement to receive any communication sent, including any telegram, telex,
teletype, telecopy, bank wire, cable, or telephone message or any writing,
application, notice, report, statement, certificate, resolution, request, order,
consent letter or other instrument or paper or communication entrusted to the
mails or to a delivery service, or (v) the assets or liabilities or financial
condition or results of operations or business or creditworthiness of the
Borrower or any of its Subsidiaries.

             (c) Reliance. The Agent shall be entitled to act, and shall be
fully protected in acting upon, any telegram, telex, teletype, telecopy, bank
wire or cable or any
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<PAGE>
 
writing, application, notice, report, statement, certificate, resolution,
request, order, consent, letter or other instrument or paper or communication
believed by the Agent in good faith to be genuine and correct and to have been
signed or sent or made by a proper Person. The Agent may consult counsel and
shall be entitled to act, and shall be fully protected in any action taken in
good faith, in accordance with advice given by counsel. The Agent may employee
agents and attorneys-in-fact and shall not be liable for the default or
misconduct of any such agents or attorneys-in-fact selected by the Agent with
reasonable care. The Agent shall not be bound to ascertain or inquire as to the
performance or observance of any of the terms, provisions or conditions of this
Agreement or any of the other Loan Documents on the part of the Borrower.

        9.06. Actions in Discretion of Agent; Instructions from the Lenders. The
Agent agrees, upon the written request of the Required Lenders, to take or
refrain from taking any action of the type specified as being within the Agent's
rights, powers or discretion herein or under any Loan Documents, provided that
the Agent shall not be required to take any action which exposes the Agent to
personal liability or which is contrary to this Agreement or any other Loan
Document or applicable Law. In the absence of a request by the Required Lenders,
the Agent shall have authority, in its sole discretion, to take or not to take
any such action, unless this Agreement specifically requires the consent of the
Required Lenders or all of the Lenders. Any action taken or failure to act
pursuant to such instructions or discretion shall be binding on the Lenders, the
L/C Issuer and the Swingline Lender, subject to Section 9.05(b) hereof. Subject
to the provisions of Section 9.05(b), none of the Lenders, the L/C Issuer and
the Swingline Lender shall have any right of action whatsoever against the Agent
as a result of the Agent acting or refraining from acting hereunder in
accordance with the instructions of the Required Lenders.

        9.07. Indemnification. To the extent Borrower does not reimburse and
save harmless the Agent according to the terms hereof for and from all costs,
expenses and disbursements in connection herewith, such costs, expenses and
disbursements, shall be borne by the Lenders ratably in accordance with
respective Lender's Ratable Share. Each Lender hereby agrees on such basis (i)
to reimburse the Agent for such Lender's Ratable Share of all such reasonable
costs, expenses and disbursements on request and (ii) to the extent of each such
Lender's Ratable Share, to indemnify and save harmless the Agent against and
from any and all losses, obligations, penalties, actions, judgments and suits
and other costs, expenses and disbursements of any kind or nature whatsoever
which may be imposed on, incurred by or asserted against the Agent, other than
as a consequence of gross negligence or willful misconduct on the part of the
Agent, arising out of or in connection with this Agreement, the other Loan
Documents or any other agreement, instrument or document in connection herewith
or therewith, or any request of the Required Lenders, including without
limitation the reasonable costs, expenses and disbursements in connection with
defending itself against any claim or liability related to the exercise or
performance of any of its powers or duties under this Agreement, the other Loan
Documents, or any of the other agreements, instruments or documents delivered in
connection herewith or the taking of any action under or in connection with any
of the foregoing.

        9.08. Agent's Rights as Lender. With respect to the Revolving Credit
Commitment of the Agent as Lender hereunder, any Loans of the Agent under this
Agreement, the Agent's Ratable Share of any Unreimbursed L/C Draws, the
participation as a Lender, and as to PNC Bank, as the L/C Issuer under this
Agreement the other Loan Documents and any other agreements, instruments and
documents delivered pursuant hereto, and the issuance of any Letter of Credit
under the terms hereof, the Agent shall have the same rights and powers, 

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duties and obligations under this Agreement, the other Loan Documents or any
other agreement, instrument or document as any Lender and may exercise such
rights and powers and shall perform such duties and fulfill such obligations as
though it were not the Agent, as the case may be. The Agent may accept deposits
from, lend money to, and generally engage, and continue to engage, in any kind
of business with the Borrower or any of its Subsidiaries.

        9.09. Notice of Default. The Agent shall not be deemed to have knowledge
or notice of the occurrence of an Event of Default unless the Agent has received
written notice from a Lender or the Borrower referring to this Agreement,
describing such Event of Default and stating that such notice is a "notice of
default".

        9.10. Payment to Lenders. Except as otherwise set forth in Section 9.03
hereof, promptly after receipt from the Borrower of any principal repayment of
the Revolving Credit Loans or any Unreimbursed L/C Draw, interest due on the
Revolving Credit Loans or any Unreimbursed L/C Draws, and any Fees (other than
the underwriting fee and the administration fee paid to the Agent and the L/C
Fronting Fee paid to the L/C Issuer) or other amounts due under any of the Loan
Documents, the Agent shall distribute to each Lender that Lender's Ratable Share
of the funds so received except that funds received from the Borrower or a
Subsidiary Guarantor to reimburse the L/C Issuer for drawings on Letters of
Credit (other than a Lender's Ratable Share of such reimbursement payment to the
extent such Lender has complied fully with any funding obligations under Section
2.17(g) hereof) or to fund any risk participant in the Letters of Credit or to
pay the L/C Fronting Fee shall be paid solely for the account of L/C Issuer. If
the Agent fails to distribute collected funds received by 1:00 P.M. on any
Business Day by 3:00 P.M. of such Business Day or collected funds received after
1:00 P.M. on any Business Day by 3:00 P.M. the next Business Day the funds shall
bear interest until distributed at the Federal Funds Effective Rate. The Agent
agrees to make its best efforts to provide telephonic notice to each Lender that
it is in receipt of funds from the Borrower and the day on which it will
commence a wire transfer of such Lender's share of such funds.

        9.11. Holders of Notes. The Agent may deem and treat any payee of any
Note as the owner thereof for all purposes hereof unless and until written
notice of the assignment or transfer thereof shall have been filed with the
Agent. Any request, authority or consent of any person who at the time of making
such request or giving such authority or consent is the holder of any Note shall
be conclusive and binding on any subsequent holder, transferee or assignee of
such Note or of any Note or Notes issued in exchange therefor.

        9.12. Equalization of Lenders. Each borrowing and each payment or
prepayment by, or for the account of, the Borrower with respect to principal,
interest, Fees, or other amounts due from the Borrower hereunder to the Lenders
with respect to the Revolving Credit Loans, shall (except as provided in Section
2.10, 2.12, 2.17(b) or 9.03 hereof) be made in proportion to the Revolving
Credit Loans outstanding from each Lender or, if no such Revolving Credit Loans
are then outstanding, in proportion to the Ratable Share of each Lender. Each
payment of Unreimbursed L/C Draws shall be made for the account of the L/C
Issuer. The Lenders agree among themselves that, with respect to all amounts
received by any Lender (in its capacity solely as a Lender) or any such holder
for application on any obligation hereunder or under any Note or under any such
participation, whether received by voluntary payment, by realization upon
security, by the exercise of the right of set-off or banker's lien, by
counterclaim or by any other non-pro rata source, equitable adjustment will be
made in the manner stated in the following sentence so that, in effect, all such
excess amounts will be shared ratably among the Lenders and such holders in
proportion to their interest in payments 

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<PAGE>
 
under the Notes, except as otherwise expressly provided herein. The Lenders or
any such holder receiving any such amount shall purchase for cash, from each of
the other Lenders, an interest in such Lender's Revolving Credit Loans in such
amount as shall result in a ratable participation by the Lenders and each such
holder in the aggregate unpaid amount under the Notes, provided that if all or
any portion of such excess amount is thereafter recovered from the Lender or the
holder making such purchase, such purchase shall be rescinded and the purchase
price restored to the extent of such recovery, together with interest or other
amounts, if any, required by Law (including court order) to be paid by the
Lender or the holder making such purchase.

        9.13. Successor Agent. The Agent may resign as the Agent upon sixty (60)
days' written notice to the Lenders and the Borrower. If such notice shall be
given, the Lenders shall appoint from among the Lenders a successor agent for
the Lenders, during such 60-day period, which successor agent shall be
reasonably satisfactory to the Borrower, to serve as agent hereunder and under
the several documents, the forms of which are attached hereto as exhibits, or
which are referred to herein. If at the end of such 60-day period the Lenders
have not appointed such a successor, the Agent shall procure a successor
reasonably satisfactory to the Lenders and the Borrower, to serve as agent for
the Lenders, the L/C Issuer and the Swingline Lender hereunder and under the
several documents, the forms of which are attached hereto as exhibits, or which
are referred to herein. Any such successor agent shall succeed to the rights,
powers and duties of the Agent. Upon the appointment of such successor agent or
upon the expiration of such 60-day period (or any longer period to which the
Agent has agreed), the former Agent's rights, powers and duties as Agent shall
be terminated, without any other or further act or deed on the part of such
former Agent or any of the parties to this Agreement. After any retiring Agent's
resignation hereunder as the Agent, the provisions of this Article IX shall
inure to the benefit of such retiring Agent as to any actions taken or omitted
to be taken by it while it was the Agent under this Agreement.

        9.14. Calculations. In the absence of gross negligence or willful
misconduct, the Agent shall not be liable for any error in computing the amount
payable to any Lender whether in respect of the Revolving Credit Loans, fees or
any other amounts due to the Lenders, the L/C Issuer or the Swingline Lender
under this Agreement. In the event an error in computing any amount payable to
any Lender, the L/C Issuer or the Swingline Lender is made, the Agent, the
Borrower and each affected Person shall, forthwith upon discovery of such error,
make such adjustments as shall be required to correct such error, and any
compensation therefor will be calculated at the Federal Funds Effective Rate.

        9.15. Beneficiaries. Except as expressly provided herein, the provisions
of this Article IX are solely for the benefit of the Agent, the Lenders, the L/C
Issuer and the Swingline Lender, and the Borrower shall not have any rights to
rely on or enforce any of the provisions hereof. In performing its functions and
duties under this Agreement, the Agent shall act solely as agent of the Lenders,
the L/C Issuer and the Swingline Lender, and does not assume and shall not be
deemed to have assumed any obligation toward or relationship of agency or trust
with or for the Borrower.

                                   ARTICLE X
                               GENERAL PROVISIONS
                               ------------------

        10.01. Amendments and Waivers. The Required Lenders, or the Agent with
the consent in writing of the Required Lenders, and the Borrower may, subject to
the provisions of 

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this Section 10.01, from time to time enter into written supplemental agreements
to this Agreement and the other Loan Documents for the purpose of adding or
deleting any provisions or otherwise changing, varying or waiving in any manner
the rights of the Lenders, the Agent or the obligor thereunder or the
conditions, provisions or terms thereof or waiving any Event of Default
thereunder or consenting to an action of any of the Borrower or any of its
Subsidiaries, but only to the extent specified in such written agreements;
provided, however, that no such supplemental agreement shall, without the
consent of all the Lenders:

                (i) waive an Event of Default by the Borrower in any payment of
principal, interest, Fees or other amounts due hereunder and under any of the
other Loan Documents, or otherwise postpone any schedule payment date of any of
the foregoing;

                (ii) reduce the interest rate relating to the Revolving Credit
Loans or change the definition of the terms Base Rate, Prime Rate, Applicable
Euro-Rate Margin, Euro-Rate, Euro-Rate Interest Period, Euro-Rate Reserve
Percentage or Federal Funds Effective Rate so as to decrease the interest rate
relating to the Revolving Credit Loans;

                (iii) extend the Expiration Date;

                (iv)  reduce any Fee due the Lenders;

                (v) increase the maximum principal amount of the Revolving
Credit Commitment of any Lender, or increase the maximum Stated Amount of
Letters of Credit which may be issued and outstanding under the terms hereof;

                (vi) change the definition of the term Required Lenders; or

                (vii) amend or waive the provisions of this Section 10.01.

Any such supplemental agreement shall apply equally to each of the Lenders, the
L/C Issuer and the Swingline Lender and shall be binding upon the Borrower, the
Lenders, the Swingline Lender and the Agent, all future holders of the Notes and
all Participants. In the case of any waiver, the Borrower, the Lenders, the L/C
Issuer, the Swingline Lender and the Agent shall be restored to former positions
and rights, and any Event of Default waived shall be deemed to be cured and not
continuing, but no such waiver shall extend to any subsequent or other Event of
Default, or impair any right consequent thereon.

        10.02. Taxes. The Borrower shall pay any and all stamp, document,
transfer and recording taxes, filing fees and similar impositions payable or
hereafter determined by the Agent, the Lenders, the L/C Issuer and the Swingline
Lender to be payable in connection with this Agreement, the other Loan Documents
and any other documents, instruments and transactions pursuant to or in
connection with any of the Loan Documents. The Borrower agrees to save the
Agent, the Lenders, the L/C Issuer and the Swingline Lender harmless from and
against any and all present and future claims or liabilities with respect to, or
resulting from, any delay in paying or failure to pay any such taxes or similar
impositions.

        10.03. Costs and Expenses, etc.

              (a)  The Borrower shall:

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                (i) pay or reimburse the Agent for all reasonable out-of-pocket
costs and expenses incurred by the Agent in connection with (A) the preparation,
negotiation and execution of this Agreement, any other Loan Documents or any
instrument or document prepared in connection herewith or therewith; (B) the
completion of the Agent's "due diligence" permitted as a condition of the
closing; (C) the syndication efforts of the Agent with respect to this Agreement
and the commitments hereunder; and (D) the consummation of the transactions
contemplated hereby and thereby (including, without limitation, in each case the
reasonable fees and out-of-pocket expenses of the counsel to the Agent); and

                (ii) reimburse the Agent, the L/C Issuer, the Swingline Lender
and each Lender on demand for all reasonable out-of-pocket costs and expenses
incurred by the Agent, the L/C Issuer, the Swingline Lender or such Lender in
connection with the enforcement of or preservation of any of its Liens, rights,
powers, interests or remedies under this Agreement or any other Loan Document
(including, without limitation, in each case the reasonable fees and out-of-
pocket expenses of the respective counsel to the Agent, the L/C Issuer, the
Swingline Lender and each Lender).

        (b) All of such costs, expenses and indemnities shall be payable by the
Borrower to the Agent, the Lenders, the L/C Issuer or the Swingline Lender as
appropriate upon demand or as otherwise agreed upon by the Agent, the Lenders,
the L/C Issuer or the Swingline Lender as appropriate and the Borrower, and
shall constitute Lender Obligations under this Agreement.

   10.04.  Notices.

        (a) Notice to the Borrower. All notices required to be delivered to the
Borrower pursuant to this Agreement shall be in writing and shall be sent to the
following address, by hand delivery, recognized national overnight courier
service with all charges prepaid, telex, telegram, telecopier or by United
States certified mail, postage prepaid:

                          Pitt-Des Moines, Inc.
                          1450 Lake Robbins Drive
                          Suite 400
                          The Woodlands, Texas 77380
                          Attention:    Richard A. Byers
                                        Vice President, Finance and Treasurer
                          Telephone:    (281) 765-4600
                          Telecopier:   (281) 765-4602

        (b) Notice to the Agent. All notices required to be delivered to the
Agent pursuant to this Agreement shall be in writing and shall be sent to the
following address, by hand delivery, recognized national overnight courier
service with all charges prepaid, telex, telegram, telecopier or by United
States certified mail, postage prepaid:

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<PAGE>
 
                              PNC Bank, National Association
                              Multibank Loan Administration
                              One PNC Plaza, 22nd Floor
                              249 Fifth Avenue
                              Pittsburgh, Pennsylvania 15222-2707
                              Attention:  Arlene M. Ohler, Vice President
                              Telephone:  412-762-3627
                              Telecopier: 412-762-8672


          (c) Notice to L/C Issuer. All notices required to be sent to the L/C
Issuer pursuant to this Agreement shall be in writing and shall be sent to the
following address by hand delivery, recognized national overnight courier
service with all charges prepaid, telex, telegram, telecopier or by United
States certified mail, postage prepaid:

                              PNC Bank, National Association
                              Multibank Loan Administration
                              One PNC Plaza, 22nd Floor
                              249 Fifth Avenue
                              Pittsburgh, Pennsylvania 15222-2707
                              Attention:  Arlene M. Ohler, Vice President
                              Telephone:  412-762-3627
                              Telecopier: 412-762-8672

          (d) Notice to the Swingline Lender. All notices required to be sent to
the Swingline Lender pursuant to this Agreement shall be in writing and shall be
sent to the following address by hand delivery, recognized national overnight
courier service with all charges prepaid, telex, telegram, telecopier or by
United States certified mail, postage prepaid:

                              PNC Bank, National Association
                              Multibank Loan Administration
                              One PNC Plaza, 22nd Floor
                              249 Fifth Avenue
                              Pittsburgh, Pennsylvania 15222-2707
                              Attention:  Arlene M. Ohler, Vice President
                              Telephone:  412-762-3627
                              Telecopier: 412-762-8672

          (e) Notice to Lenders. All notices required to be sent to the Lenders
pursuant to this Agreement shall be in writing and shall be sent to the notice
address of each Lender as set forth on Schedule 1.01 (a) hereto or such Lender's
signature page to the Assignment and Assumption Agreement executed by it as a
Purchasing Lender, as the case may be, by hand delivery, overnight courier
service with all charges prepaid, telex, telegram, telecopier or other means of
electronic data communication or by the United States mail, first class postage
prepaid.

All such notices shall be effective three days after mailing, the date of
telecopy transmission or when received, whichever is earlier. The Borrower, the
Lenders, the L/C Issuer, the Swingline Lender and the Agent may each change the
address for service of notice upon it by a notice in writing to the other
parties hereto.

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    10.05.  Participation and Assignment.

        (a)  Sale of Participation.

          (i) Any Lender may, in the ordinary course of its commercial lending
business and in accordance with applicable law, and without the consent of the
Borrower, at any time sell to one or more Participants (which Participants may
be Affiliates of such Lender) Participations in the Revolving Credit Commitment
of such Lender or any Revolving Credit Loan, the Note, or other interest of such
Lender hereunder. In the event of any such sale of a Participation, such
Lender's obligations under this Agreement to the Borrower shall remain
unchanged, such Lender shall remain solely responsible for its performance under
this Agreement, such Lender shall remain the holder of the Note made payable to
it for all purposes under this Agreement (including all voting rights hereunder)
and the Borrower shall continue to deal solely and directly with such Lender in
connection with such Lender's rights and obligations under this Agreement and
the other Loan Documents.

          (ii) As between a Participant and that Participant's selling Lender
only, the sole issues on which the Participant shall have a contractual right to
vote are: (A) an increase in such Lender's Revolving Credit Commitment, (B) any
change of the term Base Rate, Euro-Rate, Euro-Rate Reserve Percentage, or
Applicable Euro-Rate Margin so as to decrease the interest rate relating to the
Revolving Credit Loans, (C) extension of the term of the Revolving Credit
Commitment, or (D) postponement of the scheduled payment of principal, interest
or Fees due under any of the Loan Documents.

        (b) Assignments. Subject to the remaining provisions of this Section
10.05(b), any Lender may at any time, in the ordinary course of its commercial
lending business, in accordance with applicable law, sell to one or more
Purchasing Lenders (which Purchasing Lender may be affiliates of the Transferor
Lender), all or a portion of its rights and obligations under this Agreement and
the Note then held by it, pursuant to an Assignment and Assumption Agreement
substantially in the form of Exhibit "F" and satisfactory to the Agent, executed
by the Transferor Lender, such Purchasing Lender, the Agent and the Borrower;
subject, however to the following requirements:

          (i) The Agent and the Borrower must each give its prior consent to any
such assignment which consent shall not be unreasonably withheld; it being
agreed that it shall not be deemed unreasonable for the Borrower to decline to
consent to such assignment if (A) such assignment would result in incurrence of
additional costs to the Borrower under Section 2.10, 2.11 or 2.12, or (B) the
proposed assignee has not provided to the Borrower any tax forms received under
Section 10.05(d); provided, however, no consent is required for the transfer by
a Lender to its Affiliate so long as the conditions in clauses (A) and (B)
immediately above are satisfied;

          (ii) Each such assignment must be in a minimum amount of $5,000,000,
or, if in excess of $5,000,000, in integral multiples of $1,000,000; and

          (iii)  The Transferor Lender shall pay to the Agent, for its own
Account, a fee of $3,500 for each such assignment (the "ASSIGNMENT FEE").

Upon the execution, delivery, acceptance and recording of any such Assignment
and Assumption Agreement, from and after the Transfer Effective Date determined
pursuant to such 

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<PAGE>
 
Assignment and Assumption Agreement, (i) the Purchasing Lender thereunder shall
be a party hereto as a Lender and, to the extent provided in such Assignment and
Assumption Agreement, shall have the rights and obligations of a Lender
hereunder with a Revolving Credit Commitment as set forth therein, and (ii) the
Transferor Lender thereunder shall, to the extent provided in such Assignment
and Assumption Agreement, be released from its obligations under this Agreement
as a Lender. Such Assignment and Assumption Agreement shall be deemed to amend
this Agreement to the extent, and only to the extent, necessary to reflect the
addition of such Purchasing Lender as a Lender and the resulting adjustment of
Ratable Share arising from the purchase by such Purchasing Lender of all or a
portion of the rights and obligations of such Transferor Lender under this
Agreement and the Notes. On or prior to the Transfer Effective Date, the
Borrower shall execute and deliver to the Agent, in exchange for the surrendered
Note held by the Transferor Lender, a new Note to the order of such Purchasing
Lender in an amount equal to the Revolving Credit Commitment assumed by it and
purchased by it pursuant to such Assignment and Assumption Agreement, and a new
Note to the order of the Transferor Lender in an amount equal to the Revolving
Credit Commitment retained by it hereunder.

          (c) Assignment Register. The Agent shall maintain at its address
referred to in Section 10.04(b) a copy of each Assignment and Assumption
Agreement delivered to it and a register (the "REGISTER") for the recordation of
the names and addresses of the Lenders and the amount of the Revolving Credit
Loans owing to each Lender from time to time. The entries in the Register shall
be conclusive, in the absence of manifest error, and the Borrower, the Agent,
the Lender and the L/C Issuer may treat each Person whose name is recorded in
the Register as the owner of the Revolving Credit Loans recorded therein for all
purposes of this Agreement. The Register shall be available at the office of the
Agent for inspection by the Borrower or any Lender at any reasonable time and
from time to time upon reasonable prior notice.

          (d) Withholding of Income Taxes. At least five (5) Business Days prior
to the first date on which interest or fees are payable hereunder for the
account of any Purchasing Lender or Participant, each Purchasing Lender or
Participant that is not incorporated under the laws of the United States or a
state thereof shall deliver to the Borrower and the Transferor Lender two duly
completed copies of United States Internal Revenue Service Form W-9, 4224 or
1001 or other applicable form prescribed by the Internal Revenue Service. Such
form shall certify that such Purchasing Lender or Participant is entitled to
receive payments under this Agreement and the Notes without deduction or
withholding of any United States Federal income taxes, or is subject to such tax
at a reduced rate under an applicable tax treaty or under United States Internal
Revenue Service Form W-8, or another applicable form or a certificate of such
Purchasing Lender or Participant indicating that no such exemption or reduced
rate is allowable with respect to such payments. Each Purchasing Lender or
Participant which delivers a Form W-8, W-9, 4224 or 1001 further undertakes to
deliver to the Borrower and its Transferor Lender two additional copies of such
form (or a successor form) on or before the date that such form expires or
becomes obsolete or otherwise is required to be resubmitted as a condition to
obtaining an exemption from withholding tax or after the occurrence of any event
requiring a change in the most recent form so delivered by it, and such
amendments thereto or extensions or renewals thereof as may be reasonably
required by the Borrower or its Transferor Lender, either certifying that such
Purchasing Lender or Participant is entitled to receive payments under this
Agreement and the Notes without deduction or withholding of any United States
Federal income taxes or is subject to such tax at a reduced rate under an
applicable tax treaty or stating that no such exemption or reduced rate is

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<PAGE>
 
allowable. The Borrower, in the case of a Purchasing Lender or Transferor Lender
in the case of a Participant shall be entitled to withhold United States Federal
income taxes at the full withholding rate, unless the Purchasing Lender or
Participant as the case may be establishes an exemption, or at the applicable
reduced rate, as established pursuant to this provisions of this Section
10.05(d).

          (e) Assignments to Federal Reserve Bank. In addition to the
assignments permitted above, any Lender may assign and pledge all or any portion
of its Loans and Notes to any Federal Reserve Bank as collateral security
pursuant to Regulation A of the Board of Governors of the Federal Reserve System
and any Operating Circular issued by such Federal Reserve Bank. No such
assignment shall release the assigning Lender from its obligations and duties
hereunder or under the other Loan Documents.

          10.06.  Successors and Assigns. This Agreement shall be binding upon
the Borrower and the Agent, the Lenders, the L/C Issuer, the Swingline Lender
and their respective successors and assigns, and shall inure to the benefit of
the Borrower, the Agent, the Lenders, the L/C Issuer, the Swingline Lender and
respective successors and assigns; provided, however, that the Borrower shall
not assign its rights or duties hereunder or under any of the other Loan
Documents without the prior written consent of the Lenders.

          10.07.  No Implied Waivers; Cumulative Remedies; Writing Required.
No course of dealing and no delay or failure of the Agent, any Lender, the L/C
Issuer or the Swingline Lender in exercising any right, power, remedy or
privilege under this Agreement or any other Loan Document shall affect any other
or future exercise thereof or operate as a waiver thereof; nor shall any single
or partial exercise thereof or any abandonment or discontinuance of steps to
enforce such a right, power, remedy or privilege preclude any further exercise
thereof or of any other right, power, remedy or privilege. The rights and
remedies of the Agent, the Lenders, the L/C Issuer and the Swingline Lender
under this Agreement and any other Loan Documents are cumulative and not
exclusive of any rights or remedies which they would otherwise have. Any waiver,
permit, consent or approval of any kind or character on the part of the Agent,
any Lender, the L/C Issuer or the Swingline Lender of any breach or default
under this Agreement or any such waiver of any provision or condition of this
Agreement must be in writing and shall be effective only to the extent
specifically set forth in such writing.

          10.08.  Severability. Any provision of this Agreement which is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or enforceability without
invalidating the remaining portions hereof or affecting the validity or
enforceability of such provision in any other jurisdiction.

          10.09.  Indemnity. The Borrower hereby agrees to indemnify the
Agent, the Lenders, the L/C Issuer, the Swingline Lender and the directors,
officers, employees, attorneys, agents and Affiliates or all of the foregoing
(each of the foregoing an "Indemnified Person") against, and hold each of them
harmless from, any loss, liabilities, damages, claims, costs and expenses
(including reasonable attorneys' fees and disbursements) suffered or incurred by
any Indemnified Person (except those caused by such Indemnified Person's gross
negligence or willful misconduct, ) arising out of, resulting from or in any
manner connected with, the execution, delivery and performance of each of the
Loan Documents, the Lender Obligations and any and all transactions related to
or consummated in connection with the Lender Obligations, including, without
limitation, losses, liabilities, damages, claims, costs and expenses suffered or
incurred by any Indemnified Person arising out of or related to 

                                       77
<PAGE>
 
investigating, preparing for, defending against, or providing evidence,
producing documents or taking any other action in respect of any commenced or
threatened litigation, administrative proceeding or investigation under any
Federal securities law or by any Official Body of any jurisdiction, or at common
law or otherwise, that is alleged to arise out of or is based on (i) any untrue
statement or alleged untrue statement of any material fact of the Borrower or
any Affiliate of the Borrower in any document or schedule filed with the
Securities and Exchange Commission or any other Official Body, (ii) any omission
or alleged omission to state any material fact required to be stated in such
document or schedule, or necessary to make the statements made therein, in light
of the circumstances under which made, not misleading; (iii) any actual or
alleged acts, practices or omissions of the Borrower, any Subsidiary Guarantor,
or any of their respective directors, officers, partners, employees, attorneys,
agents or Affiliates, related to the making of any acquisition, purchase of
shares or assets pursuant thereto, financing of such purchases or the
consummation of any other transactions contemplated by any such acquisitions
that are alleged to be in violation of any Federal securities law or of any
other statute, regulation or other law of any jurisdiction applicable to the
making of any such acquisition, the purchase of shares or assets pursuant
thereto, the financing of such purchases or the consummation of the other
transactions contemplated by any such acquisition; or (iv) any withdrawals,
termination or cancellation of any such proposed acquisition for any reason
whatsoever. The indemnity set forth in this Section 10.9 shall be in addition to
any other obligations or liabilities of the Borrower to the Agent, the Lenders,
the L/C Issuer or the Swingline Lender, or at common law or otherwise. The
provisions of this Section 10.9 shall survive the payment of the Lender
Obligations and the termination of this Agreement and the other Loan Documents.

          10.10  Confidentiality. The Agent, the Lenders, the L/C Issuer and
the Swingline Lender shall keep confidential and not disclose to any Person,
other than to their respective directors, officers, employees, Affiliates and
agents, and to actual and potential Purchasing Lenders and Participants, all
non-public information concerning the Borrower and the Borrower's Affiliates
which comes into the possession of the Agent, the Lenders, the L/C Issuer or the
Swingline Lender during the term hereof. Notwithstanding the foregoing, the
Agent, the Lenders, the L/C Issuer and the Swingline Lender may disclose
information concerning the Borrower (i) in accordance-with normal banking
practices and the Agent's, such Lender's, the L/C Issuer's or the Swingline
Lender's policies concerning disclosure of such information in connection with
syndication or sales of Participations, subject to informing the recipient of
such information of the duties of confidentiality hereunder, (ii) pursuant to
what the Agent, such Lender, the L/C Issuer or the Swingline Lender believes to
be the lawful requirements or request of any Official Body regulating banks or
banking, (iii) as required by governmental regulation or rule, judicial process
or subpoena; provided however, if permitted by law, the Agent, such Lender, the
L/C Issuer or the Swingline Lender shall notify the Borrower and permit the
Borrower, at the Borrower's cost, to contest such subpoena; and (iv) to their
respective attorneys, accountants and auditors who have been informed of the
confidentiality hereunder.

          10.11.  Survival. All representations, warranties, covenants and
agreements of the Borrower contained herein or in the other Loan Documents or
made in writing in connection herewith shall survive the issuance of the Notes
and the Letters of Credit and shall continue in full force and effect so long as
the Borrower may borrow hereunder and so long thereafter until payment in full
of all the Notes and the Lender Obligations is made. The obligations of the
Borrower under Sections 6.13, 10.02 and 10.03 shall survive the termination of
this Agreement and the discharge of the other obligations of the Borrower
hereunder, and any other Loan Documents, and shall also survive the payment in
full of all Lender Obligations, the termination 

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<PAGE>
 
of the Revolving Credit Commitment in accordance with the provisions of this
Agreement and the termination or expiration of all Letters of Credit in
accordance with their respective terms.

          10.12.  GOVERNING LAW. THIS AGREEMENT AND THE OTHER LOAN DOCUMENTS
SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE
COMMONWEALTH OF PENNSYLVANIA, WITHOUT REGARD TO THE PRINCIPLES THEREOF REGARDING
CONFLICT OF LAWS, EXCEPTING APPLICABLE FEDERAL LAW AND EXCEPT ONLY TO THE EXTENT
PRECLUDED BY THE MANDATORY APPLICATION OF THE LAW OF ANOTHER JURISDICTION.

          10.13.  FORUM. THE PARTIES HERETO AGREE THAT ANY ACTION OR
PROCEEDING ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE OTHER LOAN
DOCUMENTS TO WHICH THE BORROWER IS A PARTY MAY BE COMMENCED IN THE COURT OF
COMMON PLEAS OF ALLEGHENY COUNTY, PENNSYLVANIA OR IN THE DISTRICT COURT OF THE
UNITED STATES FOR THE WESTERN DISTRICT OF PENNSYLVANIA, AND THE PARTIES HERETO
AGREE THAT A SUMMONS AND COMPLAINT COMMENCING AN ACTION OR PROCEEDING IN EITHER
OF SUCH COURTS SHALL BE PROPERLY SERVED AND SHALL CONFER PERSONAL JURISDICTION
IF SERVED PERSONALLY OR BY CERTIFIED MAIL TO THE PARTIES AT THEIR ADDRESSES SET
FORTH IN SECTION 10.04, OR AS OTHERWISE PROVIDED UNDER THE LAWS OF THE
COMMONWEALTH OF PENNSYLVANIA. FURTHER, THE BORROWER HEREBY SPECIFICALLY CONSENTS
TO THE PERSONAL JURISDICTION OF THE COURT OF COMMON PLEAS OF ALLEGHENY COUNTY,
PENNSYLVANIA AND THE DISTRICT COURT OF THE UNITED STATES FOR THE WESTERN
DISTRICT OF PENNSYLVANIA AND WAIVES AND HEREBY ACKNOWLEDGES THAT IT IS ESTOPPED
FROM RAISING ANY OBJECTION BASED ON FORUM NON CONVENIENS, ANY CLAIM THAT EITHER
SUCH COURT LACKS PROPER VENUE OR ANY OBJECTION THAT EITHER SUCH COURT LACKS
PERSONAL JURISDICTION OVER THE BORROWER SO AS TO PROHIBIT EITHER SUCH COURT FROM
ADJUDICATING ANY ISSUES RAISED IN A COMPLAINT FILED WITH EITHER SUCH COURT
AGAINST THE BORROWER BY THE AGENT, THE LENDERS, THE L/C ISSUER OR THE SWINGLINE
LENDER CONCERNING THIS AGREEMENT OR THE OTHER LOAN DOCUMENTS OR PAYMENT TO THE
AGENT, THE L/C ISSUER, THE SWINGLINE LENDER OR THE LENDERS. THE BORROWER HEREBY
ACKNOWLEDGES AND AGREES THAT THE CHOICE OF FORUM CONTAINED IN THIS SECTION 10.13
SHALL NOT BE DEEMED TO PRECLUDE THE ENFORCEMENT OF ANY JUDGMENT OBTAINED IN ANY
FORUM OR THE TAKING OF ANY ACTION UNDER THE LOAN DOCUMENTS TO ENFORCE THE SAME
IN ANY APPROPRIATE JURISDICTION.

          10.14.  Non-Business Days. Whenever any payment hereunder or under
the Notes is due and payable on a day which is not a Business Day, such payment
may be made on the next succeeding Business Day, and such extension of time
shall in each such case be included in computing interest in connection with
such payment.

          10.15.  Integration. This Agreement and the other Loan Documents
constitute the entire agreement between the parties relating to this financing
transaction and they supersede all prior understandings and agreements, whether
written or oral, between the parties hereto relating to the transactions
provided for herein.

          10.16.  Counterparts. This Agreement and any amendment hereto may be
executed in several counterparts and by each party on a separate counterpart,
each of which, 

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when so executed and delivered, shall be an original, but all of which together
shall constitute but one and the same instrument. In proving this Agreement, it
shall not be necessary to produce or account for more than one such counterpart
signed by the other party against whom enforcement is sought. Delivery of an
executed counterpart of a signature page to this Agreement by telecopier shall
be as effective as delivery of a manually executed counterpart of this
Agreement.

        10.17.  Funding by Branch, Subsidiary or Affiliate.

          (a) Notional Funding. Each Lender shall have the right from time to
time, without notice to the Borrower, to deem any branch, subsidiary or
affiliate (which for the purposes of this Section 10.17 shall mean any
corporation or association which is directly or indirectly controlled by or is
under direct or indirect common control with any corporation or association
which directly or indirectly controls such Lender) of such Lender to have made,
maintained or funded any Revolving Credit Loan to which the Euro-Rate Option
applies at any time, provided that immediately following (on the assumption that
a payment were then due from the Borrower to such other office) and as a result
of such change the Borrower would not be under any greater financial obligation
to such Lender hereunder, pursuant to Section 2.08, 2.10, 2.11 or 2.12 hereof
than it would have been in the absence of such change. Notional funding offices
may be selected by each Lender without regard to a Lender's actual methods of
making, maintaining or funding the Revolving Credit Loans or any sources of
funding actually used by or available to such Lender.

          (b) Actual Funding. Each Lender shall have the right from time to time
to make or maintain any Revolving Credit Loan by arranging for a branch,
subsidiary or affiliate of such Lender to make or maintain such Revolving Credit
Loan subject to the last sentence of this Section 10.17(b). If any Lender causes
a branch, subsidiary or affiliate to make or maintain any part of the Revolving
Credit Loans hereunder, all terms and conditions of this Agreement shall, except
where the context clearly requires otherwise, be applicable to such part of the
Revolving Credit Loans to the same extent as if such Revolving Credit Loans were
made or maintained by such Lender but in no event shall any Lender's use of such
a branch, subsidiary or affiliate to make or maintain any part of the Revolving
Credit Loans hereunder cause such Lender or such branch, subsidiary or affiliate
to incur any cost or expenses payable by the Borrower hereunder or require the
Borrower to pay any other compensation to any such Lender (including, without
limitation, any expenses incurred or payable pursuant to Section 2.08, 2.10,
2.11 or 2.12 hereof) which would otherwise not be incurred.

        10.18 WAIVER OF JURY TRIAL. THE BORROWER, EACH LENDER, THE AGENT, THE
L/C ISSUER AND THE SWINGLINE LENDER EACH HEREBY WAIVES THE RIGHT TO TRIAL BY
JURY IN ANY COURT AND IN ANY ACTION OR PROCEEDING OF ANY TYPE IN WHICH THE
BORROWER, THE LENDERS, THE AGENT, THE L/C ISSUER AND THE SWINGLINE LENDER OR ANY
OF THEIR RESPECTIVE SUCCESSORS OR ASSIGNS IS A PARTY, AS TO ALL MATTERS AND
THINGS ARISING OUT OF THIS AGREEMENT, THE NOTES OR THE OTHER LOAN DOCUMENTS.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

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<PAGE>
 
          IN WITNESS WHEREOF, the parties hereto, intending to be legally bound
hereby, have caused this Revolving Credit and Letter of Credit Issuance
Agreement to be executed by their respective duly authorized officers as of the
date first written above.

                              PITT-DES MOINES, INC.,
                              a Pennsylvania corporation


                              By: /s/  R.A. Byers                 (SEAL)
                                 ---------------------------------
                              Name:  R.A. Byers
                              Title: Vice President-Finance, Treasurer

                              PNC BANK, NATIONAL ASSOCIATION, in its capacities
                              as Agent, L/C Issuer, Swingline Lender and as a
                              Lender


                              By: /s/  David B. Gookin            (SEAL)
                                 ---------------------------------
                              Name:  David B. Gookin
                              Title: Vice President 


                              AMERICAN NATIONAL BANK

                              By: /s/  James R. Popp              (SEAL)
                                 ---------------------------------
                              Name:  James R. Popp
                              Title: 1st Vice President 


                              WELLS FARGO BANK, N.A.


                              By: /s/ Judy L. Pallios             (SEAL)
                                 ---------------------------------
                              Name:  Judy L. Pallios
                              Title: Vice President

 
                              LASALLE NATIONAL BANK


                              By: /s/ Kurt A. Gibson              (SEAL)
                                 ---------------------------------
                              Name:  Kurt A. Gibson
                              Title: Vice President

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