<PAGE>
 
                                                 Exhibit (4)-31
                                                 Unicom Corporation
                                                 Form 10-K File No. 1-11375

                                                         EXECUTION COPY





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



                           U.S. $200,000,000

                          AMENDED AND RESTATED
                            CREDIT AGREEMENT
                     Dated as of November 15, 1996


                                 Among


                        UNICOM ENTERPRISES INC.
                              as Borrower


                         THE BANKS NAMED HEREIN
                                as Banks


                                  and


                             CITIBANK, N.A.
                                as Agent





===========================================================================
<PAGE>
 
                              TABLE OF CONTENTS

Section                                                            Page
-------                                                            ----

                  ARTICLE I DEFINITIONS AND ACCOUNTING TERMS
1.01.  Certain Defined Terms.......................................   1
1.02.  Computation of Time Periods.................................  16
1.03.  Accounting Terms............................................  17

                 ARTICLE II AMOUNTS AND TERMS OF THE ADVANCES
2.01.  The Advances................................................  17
2.02.  Making the Advances.........................................  17
2.03.  Computations of Outstandings................................  19
2.04.  Fees........................................................  19
2.05.  Reduction of the Commitments................................  20
2.06.  Repayment of Advances.......................................  20
2.07.  Interest on Advances........................................  20
2.08.  Additional Interest on Eurodollar Advances..................  21
2.09.  Interest Rate Determination.................................  21
2.10.  Conversion of Advances......................................  23
2.11.  Optional Prepayments of Advances............................  23
2.12.  Mandatory Prepayments.......................................  24
2.13.  Increased Costs.............................................  25
2.14.  Illegality..................................................  26
2.15.  Payments and Computations...................................  27
2.16.  Taxes.......................................................  28
2.17.  Sharing of Payments, Etc....................................  30
2.18.  Extension of Termination Date...............................  31
2.19.  Advances Outstanding Under Existing Credit Agreement........  31

                        ARTICLE III LETTERS OF CREDIT
3.01.  LC Banks....................................................  32
3.02.  Letters of Credit...........................................  32
3.03.  LC Bank Fees................................................  33
3.04.  Reimbursement to LC Banks...................................  33
3.05.  Obligations Absolute........................................  34
3.06.  Liability of LC Banks and the Lenders.......................  35

                       ARTICLE IV CONDITIONS OF LENDING
4.01.  Condition Precedent to Initial Extension of Credit..........  36
4.02.  Conditions Precedent to Each Extension of Credit............  38
4.03.  Conditions Precedent to Certain Extensions of Credit........  38

                                  -i-
<PAGE>
 
Section                                                            Page
-------                                                            ----

4.04.  Reliance on Certificates....................................  39

                   ARTICLE V REPRESENTATIONS AND WARRANTIES
5.01.  Representations and Warranties of the Borrower..............  39

                     ARTICLE VI COVENANTS OF THE BORROWER
6.01.  Affirmative Covenants.......................................  42
6.02.  Negative Covenants..........................................  46

                        ARTICLE VII EVENTS OF DEFAULT
7.01.  Events of Default...........................................  49
7.02.  Remedies....................................................  53

                            ARTICLE VIII THE AGENT
8.01.  Authorization and Action....................................  54
8.02.  Agent's Reliance, Etc.......................................  54
8.03.  Citibank and Affiliates.....................................  55
8.04.  Lender Credit Decision......................................  55
8.05.  Indemnification.............................................  56
8.06.  Successor Agent.............................................  56

                           ARTICLE IX MISCELLANEOUS
9.01.  Amendments, Etc.............................................  57
9.02.  Notices, Etc................................................  57
9.03.  No Waiver; Remedies.........................................  58
9.04.  Costs, Expenses, Taxes and Indemnification..................  58
9.05.  Right of Set-Off............................................  60
9.06.  Binding Effect..............................................  60
9.07.  Assignments and Participations..............................  60
9.08.  WAIVER OF JURY TRIAL........................................  64
9.09.  Consent.....................................................  65
9.10.  Governing Law...............................................  65
9.11.  Relation of the Parties; No Beneficiary.....................  65
9.12.  Execution in Counterparts...................................  65
9.13.  Severability................................................  66
9.14.  Headings....................................................  66
9.15.  Entire Agreement............................................  66

                                  -ii-
<PAGE>
 
Section                                                            Page
-------                                                            ----

Schedule I     -     List of Applicable Lending Offices

Exhibit A      -     Form of Note

Exhibit B-1    -     Form of Notice of Borrowing

Exhibit B-2    -     Form of Notice of Conversion

Exhibit C      -     Form of Lender Assignment

Exhibit D      -     Form of LC Bank Agreement

Exhibit E      -     Form of Guaranty

Exhibit F      -     Form of Opinion of Counsel for the Borrower and the Parent

Exhibit G      -     Form of Opinion of Special New York Counsel to the Agent

Exhibit H      -     Terms of Subordination










                                 -iii-
<PAGE>
 
                          AMENDED AND RESTATED
                            CREDIT AGREEMENT

                     Dated as of November 15, 1996



     THIS AMENDED AND RESTATED CREDIT AGREEMENT is made by and among:

        (i)     Unicom Enterprises Inc., an Illinois corporation (the
                "BORROWER"),

        (ii)    the banks (the "BANKS") listed on the signature pages
                hereof and the other Lenders (as hereinafter defined)
                from time to time party hereto, and

        (iii)   Citibank, N.A. ("CITIBANK"), as agent (the "AGENT") for
                the Lenders hereunder.


                         PRELIMINARY STATEMENT

     The Borrower has requested Citibank and the other Banks to provide a
credit facility on the terms and conditions set forth herein.  The Banks have
so agreed on the terms and conditions set forth herein, and Citibank has
agreed to continue to act as agent for the Lenders on such terms and
conditions.

     Accordingly, the parties hereto hereby agree as follows:



                               ARTICLE I
                    DEFINITIONS AND ACCOUNTING TERMS

     SECTION 1.01.  Certain Defined Terms.  As used in this Agreement, the
following terms shall have the following meanings (such meanings to be equally
applicable to both the singular and plural forms of the terms defined):

     "ADVANCE" means an advance by a Lender to the Borrower pursuant to
Section 2.01 (or deemed made pursuant to Section 3.04(d)) as part of a
Borrowing and refers to an Alternate Base Rate Advance or a Eurodollar Rate
Advance, each of which shall be a "Type" of Advance.  All Advances by a Lender
of the same Type, having the same Interest
<PAGE>
 
                                                                             2

Period and made or Converted on the same day shall be deemed to be a single
Advance by such Lender until repaid or next Converted.

     "AFFILIATE" means, with respect to any Person, any other Person directly
or indirectly controlling (including but not limited to all directors and
officers of such Person), controlled by, or under direct or indirect common
control with such Person.  A Person shall be deemed to control another entity
if such Person possesses, directly or indirectly, the power to direct or cause
the direction of the management and policies of such entity, whether through
the ownership of voting securities, by contract, or otherwise.

     "ALTERNATE BASE RATE" means a fluctuating interest rate per annum as
shall be in effect from time to time which rate per annum shall at all times
be equal to the highest of:

          (a)     the rate of interest announced publicly by Citibank in New
        York, New York, from time to time, as Citibank's base rate;

          (b)     1/2 of one percent per annum above the latest three-week
        moving average of secondary market morning offering rates in the United
        States for three-month certificates of deposit of major United States
        money market banks, such three-week moving average being determined
        weekly by the Agent on the basis of such rates reported by certificate
        of deposit dealers to and published by the Federal Reserve Bank of New
        York or, if such publication shall be suspended or terminated, on the
        basis of quotations for such rates received by the Agent from three New
        York certificate of deposit dealers of recognized standing selected by
        the Agent, in either case adjusted to the nearest 1/4 of one percent
        or, if there is no nearest 1/4 of one percent, to the next higher 1/4
        of one percent; and

          (c)     1/2 of one percent per annum above the Federal Funds Rate.

Each change in the Alternate Base Rate shall take effect concurrently with any
change in such base rate, such moving average or the Federal Funds Rate.
<PAGE>
 
                                                                             3

     "ALTERNATE BASE RATE ADVANCE" means an Advance that bears interest as
provided in Section 2.07(a).

     "APPLICABLE LAW" means, with respect to any matter or Person, any law,
rule, regulation, order, decree, or other requirement having the force of law
relating to such matter or Person and, where applicable, any interpretation
thereof by any authority having jurisdiction with respect thereto or charged
with the administration thereof.

     "APPLICABLE LENDING OFFICE" means, with respect to each Lender, such
Lender's Domestic Lending Office, in the case of an Alternate Base Rate
Advance, and such Lender's Eurodollar Lending Office, in the case of a
Eurodollar Rate Advance.

     "APPLICABLE MARGIN" means, on any date, as adjusted from time to time as
set forth below, for a Eurodollar Rate Advance or an Alternate Base Rate
Advance, the basis points (1 basis point equaling 0.01%) per annum set forth,
in the columns identified as Level 1, Level 2 or Level 3 below, opposite the
rate applicable to such Advance:


                  Level 1               Level 2               Level 3
                  -------               -------               -------
S&P            A- or better          BBB- or better          BB+ or below
Moody's        A3 or better          Baa3 or better          Ba1 or below
D&P            A- or better          BBB- or better          BB+ or below

Eurodollar
  Rate         50.00                 80.00                   125.00
Alternate Base
  Rate         0                     0                       0

                    (Basis Points Per Annum)

The Applicable Margin shall be determined on the basis of the two highest
ratings applicable to the First Mortgage Bonds at the time of determination;
provided, however, if there shall be ratings from only two Rating Agencies or
there is a "split" rating, the Applicable Margin shall be determined on the
basis of the lower of the two ratings then applicable; provided, further, that
if no Rating Agency shall then be rating the First Mortgage Bonds, then the
Applicable Margin shall be that corresponding to Level 3.

The Applicable Margins shall be increased or decreased in accordance with this
definition upon any change in the applicable ratings, and such increased or
decreased Applicable Margins shall be effective from the date
<PAGE>
 
                                                                             4

of announcement of such new ratings by the applicable Rating Agency.  The
Borrower agrees to notify the Agent promptly upon each change in any rating of
the First Mortgage Bonds.

In addition, each of the foregoing Applicable Margins applicable to Eurodollar
Rate Advances shall be increased by 5 basis points (0.05%) per annum in the
event that, and at all times during which, the principal amount outstanding
hereunder exceeds 50% of the aggregate amount of the Commitments.

          "APPLICABLE RATE" means:

     (i)     in the case of each Alternate Base Rate Advance, a rate per annum
equal at all times to the sum of the Alternate Base Rate plus the Applicable
Margin in effect from time to time; and

     (ii)     in the case of each Eurodollar Rate Advance comprising part of
the same Borrowing, a rate per annum during each Interest Period equal at all
times to the sum of the Eurodollar Rate for such Interest Period plus the
Applicable Margin in effect from time to time during such Interest Period.

     "AVAILABLE COMMITMENT" means, for each Lender on any day, the unused
portion of such Lender's Commitment, computed after giving effect to all
Extensions of Credit or prepayments to be made on such day and the application
of proceeds therefrom.

     "AVAILABLE COMMITMENTS" means the aggregate of the Lenders' Available
Commitments hereunder.

     "BANKRUPTCY CODE" means the Bankruptcy Reform Act of 1978, as amended, as
the same may be further amended, and any other applicable state or federal law
with respect to bankruptcy, liquidation, insolvency or reorganization.

     "BORROWING" means a borrowing consisting of simultaneous Advances of the
same Type, having the same Interest Period (in the case of Eurodollar Rate
Advances) and made or Converted on the same day by each of the Lenders,
ratably in accordance with their respective Percentages. Any Borrowing
consisting of Advances of a particular Type may be referred to as being a
Borrowing of such "Type".  All Advances of the same Type, having the same
Interest Period (in the case of
<PAGE>
 
                                                                             5

Eurodollar Rate Advances) and made or Converted on the same day shall be
deemed a single Borrowing hereunder until repaid or next Converted.

     "BUSINESS DAY" means a day of the year on which banks are not required or
authorized to close in New York City or Chicago, and, if the applicable
Business Day relates to any Eurodollar Rate Advance, on which dealings in
Dollar deposits are carried on in the London interbank market.

     "CAPITALIZED LEASE" means, with respect to any Person, any lease which,
in accordance with GAAP, has been, or should be, recorded as a capitalized
lease in such Person's financial statements.

     "CODE" means the Internal Revenue Code of 1986 or any successor statute,
and the regulations promulgated and rulings issued thereunder, each as in
effect and amended or modified from time to time.  References herein to
sections of the Code shall be deemed to refer to the corresponding sections of
any successor statute.

     "COMMITMENT" means, for each Lender, the obligation of such Lender to
make Advances to the Borrower and to participate in Extensions of Credit
resulting from the issuance (or extension, modification or amendment) of any
Letter of Credit in an aggregate amount no greater than the amount set forth
opposite such Lender's name on the signature pages hereof or, if such Lender
has entered into one or more Lender Assignments, set forth for such Lender in
the Register maintained by the Agent pursuant to Section 9.07(c), in each such
case as such amount may be reduced from time to time pursuant to Section
2.05.  "COMMITMENTS" means the total of the Lenders' Commitments hereunder.
The Commitments shall in no event exceed $200,000,000.

     "COMMITMENT FEE" means, with respect to any Lender, a fee that shall be
payable on the average daily Available Commitment of such Lender from time to
time, at the rate per annum set forth below.  As described below, the
Commitment Fee will be based upon the ratings of the First Mortgage Bonds as
set forth in the columns identified as Level 1, Level 2 or Level 3:

                Level 1                Level 2                Level 3
                -------                -------                -------
S&P          A- or better          BBB- or better          BB+ or below
Moody's      A3 or better          Baa3 or better          Ba1 orbelow
D&P          A- or better          BBB- or better          BB+ or below
             ------------          --------------          ------------

Commitment   20.00                 30.00                   40.00
  Fee                    (Basis Points Per Annum)
<PAGE>
 
                                                                             6

The Commitment Fee shall be determined on the basis of the two highest ratings
applicable to the First Mortgage Bonds at the time of determination; provided,
however, if there shall be ratings from only two Rating Agencies or there is a
"split" rating, the Commitment Fee shall be determined on the basis of the
lower of the two ratings then applicable; provided, further, that if no Rating
Agency shall then be rating the First Mortgage Bonds, then the Commitment Fee
shall be that corresponding to Level 3.

The Commitment Fee shall be increased or decreased in accordance with this
definition upon any change in the applicable ratings, and such increased or
decreased Commitment Fee shall be effective from the date of announcement of
such new ratings by the applicable Rating Agency.  The Borrower agrees to
notify the Agent promptly upon each change in any rating of the First Mortgage
Bonds.

     "COMMONWEALTH" means Commonwealth Edison Company, an Illinois
corporation.

     "CONTINGENT OBLIGATION" means, as to any Person, the undrawn face amount
of any letters of credit issued for the account of such Person and shall also
mean any monetary obligation of such Person guaranteeing or in effect
guaranteeing any Debt, leases, dividends, letters of credit, or other
obligations ("primary obligations") of any other Person (the "primary
obligor") in any manner, whether directly or indirectly, including, without
limitation, any obligation of such Person, whether or not contingent, (a) to
purchase any such primary obligation or any property constituting direct or
indirect security therefor, (b) to advance or supply funds (i) for the
purchase or payment of any such primary obligation or (ii) to maintain working
capital or equity capital of the primary obligor or otherwise to maintain the
net worth or solvency of the primary obligor, (c) to purchase property,
securities, or services primarily for the purpose of assuring the obligee
under any such primary obligation of the ability of the primary obligor to
make payment of such primary obligation, or (d) otherwise to assure or hold
harmless the obligee under such primary obligation against loss in respect
thereof; provided, however, that the term Contingent Obligation shall not
include endorsements of instruments for deposit or collection in the ordinary
course of business.  The amount of any Contingent Obligation shall be deemed
to be an amount equal to the stated or determinable amount of the primary
obligation or, where such Contingent Obligation is specifically limited to a
portion of any such
<PAGE>
 
                                                                             7

primary obligation, that portion to which it is limited or, if not stated or
determinable, the maximum reasonably anticipated liability in respect thereof
(assuming such Person is required to perform thereunder) as determined by such
Person in good faith.  For purposes of computing the consolidated Debt of any
Person, the amount of any primary obligation of any Subsidiary of such Person
and the amount of any Contingent Obligation of such Person corresponding to
such primary obligation shall only be counted once (i.e., without duplication).

     "CONVERT", "CONVERSION" AND "CONVERTED" each refers to a conversion of
Advances of one Type into Advances of another Type, or to the selection of a
new, or the renewal of the same, Interest Period for Eurodollar Rate Advances,
as the case may be, pursuant to Section 2.09 or 2.10.

     "D&P" means Duff & Phelps, Inc. or any successor thereto.

     "DEBT"  of a Person means (without duplication) (i) indebtedness of such
Person for borrowed money, (ii) obligations of such Person evidenced by bonds,
debentures, notes, or other similar instruments, (iii) obligations of such
Person to pay the deferred purchase price of property or services, (iv)
obligations of such Person as lessee under Capitalized Leases, (v)
indebtedness of such Person consisting of unpaid reimbursement obligations in
respect of all drafts drawn or demands for payment made under letters of
credit issued for the account of such Person, (vi) all Contingent Obligations
of such Person, (vii) liabilities of such Person in respect of unfunded vested
benefits under Pension Plans covered by Title IV of ERISA (other than
Multiemployer Plans), and (viii) withdrawal liability of such Person incurred
under ERISA to any Multiemployer Plan (including, without limitation, with
respect to each of the foregoing clauses (i) through (vi), any such
indebtedness, obligations, or liabilities that is non-recourse to the credit
of such Person but is secured by assets of such Person, and otherwise
excluding any such indebtedness, obligations or liabilities that is
non-recourse to the credit of such Person; provided, however, that Debt of the
Borrower shall not include any Contingent Obligations of the Borrower that are
non-recourse to the credit of the Borrower and are secured only by Liens
permitted by Section 6.02(e)(ii)).

     "DEFAULT RATE" means a rate per annum equal at all times to 2% per annum
above (i) in the case of a Eurodollar Rate Advance, the
<PAGE>
 
                                                                             8

Applicable Rate therefore immediately prior to such Default Rate becoming
applicable, and (ii) in all other cases, the Alternate Base Rate.

     "DOLLARS" and the sign "$" each means lawful money of the United States.

     "DOMESTIC LENDING OFFICE" means, with respect to any Lender, the office
or Affiliate of such Lender specified as its "Domestic Lending Office"
opposite its name on Schedule I hereto or in the Lender Assignment pursuant to
which it became a Lender, or such other office or Affiliate of such Lender as
such Lender may from time to time specify in writing to the Borrower and the
Agent.

     "EFFECTIVE DATE" means the date on which each of the conditions precedent
enumerated in Section 4.01 shall have been fulfilled to the satisfaction of
the Lenders, the Agent and the Borrower.

     "ELIGIBLE ASSIGNEE" means (a) any Lender; (b) any other commercial bank
or trust company organized under the laws of the United States, or any State
thereof; (c) any other commercial bank organized under the laws of any other
country that is a member of the OECD, or a political subdivision of any such
country, provided that such bank is acting through a branch or agency located
in the United States; (d) the central bank of any country that is a member of
the OECD; and (e) any other commercial bank or other financial institution
engaged generally in the business of extending credit or purchasing debt
instruments; provided, however, that (i) any such Person shall also (A) have
outstanding unsecured long-term indebtedness that is rated A-, A3 or A- or
better, or unsecured short-term indebtedness that is rated A-2, P-2 or D-2 or
better, by any two of S&P, Moody's or D&P, respectively, and (B) have combined
capital and surplus (as established in its most recent report of condition to
its primary regulator) of not less than $250,000,000 (or its equivalent in
foreign currency), (ii) any Person described in clause (c), (d), or (e),
above, shall, on the date on which it is to become a Lender hereunder, (A) be
entitled to receive payments hereunder without deduction or withholding of any
United States Federal income taxes (as contemplated by Section 2.16) and (B)
not be incurring any losses, costs or expenses of the type for which such
Person could demand payment under Section 2.13, and (iii) any Person described
in clause (b), (c), (d), or (e), above, shall, in addition, be reasonably
acceptable to the Agent and each LC Bank based upon its then-existing credit
criteria.
<PAGE>
 
                                                                             9

     "ENVIRONMENTAL LAWS" means any federal, state or local laws, ordinances
or codes, rules, orders, or regulations relating to pollution or protection of
the environment, including, without limitation, laws relating to Hazardous
Substances, laws relating to reclamation of land and waterways and laws
relating to emissions, discharges, releases or threatened releases of
pollutants, contaminants, chemicals, or industrial, toxic or hazardous
substances or wastes into the environment (including, without limitation,
ambient air, surface water, ground water, land surface or subsurface strata)
or otherwise relating to the manufacture, processing, distribution, use,
treatment, storage, disposal, transport or handling of pollution,
contaminants, chemicals, industrial or toxic wastes or other Hazardous
Substances.

     "ERISA" means the Employee Retirement Income Security Act of 1974, as
amended, and any successor statute of similar import, together with the
regulations thereunder, in each case as in effect from time to time.
References to sections of ERISA also refer to any successor sections.

     "ERISA AFFILIATE" of any Person means any trade or business (whether or
not incorporated) that is a member of a group of which such Person is a member
and that is under common control with such Person within the meaning of
Section 414 of the Code.

     "EUROCURRENCY LIABILITIES" has the meaning assigned to that term in
Regulation D of the Board of Governors of the Federal Reserve System, as in
effect from time to time.

     "EURODOLLAR LENDING OFFICE" means, with respect to any Lender, the office
or Affiliate of such Lender specified as its "Eurodollar Lending Office"
opposite its name on Schedule I hereto or in the Lender Assignment pursuant to
which it became a Lender (or, if no such office is specified, its Domestic
Lending Office), or such other office or Affiliate of such Lender as such
Lender may from time to time specify in writing to the Borrower and the Agent.

     "EURODOLLAR RATE" means, for each Interest Period for each Eurodollar
Rate Advance made as part of the same Borrowing, an interest rate per annum
equal to the average (rounded upward to the nearest whole multiple of 1/16 of
1% per annum, if such average is not such a multiple) of the rate per annum at
which deposits in Dollars are offered by the principal office of each of the
Reference Banks in London, England to prime banks in the London interbank
market at 11:00 A.M. (London time)
<PAGE>
 
                                                                            10
two Business Days before the first day of such Interest Period in an amount
substantially equal to such Reference Bank's Eurodollar Rate Advance made as
part of such Borrowing and for a period equal to such Interest Period.  The
Eurodollar Rate for the Interest Period for each Eurodollar Rate Advance made
as part of the same Borrowing shall be determined by the Agent on the basis of
applicable rates furnished to and received by the Agent from the Reference
Banks two Business Days before the first day of such Interest Period, subject,
however, to the provisions of Section 2.09.

     "EURODOLLAR RATE ADVANCE" means an Advance that bears interest as
provided in Section 2.07(b).

     "EURODOLLAR RESERVE PERCENTAGE" of any Lender for each Interest Period
for each Eurodollar Rate Advance means the reserve percentage applicable to
such Lender during such Interest Period (or if more than one such percentage
shall be so applicable, the daily average of such percentages for those days
in such Interest Period during which any such percentage shall be so
applicable) under Regulation D or other regulations issued from time to time
by the Board of Governors of the Federal Reserve System (or any successor) for
determining the maximum reserve requirement (including, without limitation,
any emergency, supplemental or other marginal reserve requirement) then
applicable to such Lender with respect to liabilities or assets consisting of
or including Eurocurrency Liabilities having a term equal to such Interest
Period.

     "EVENT OF DEFAULT" has the meaning assigned to that term in Section 7.01.

     "EXCHANGE ACT" means the Securities Exchange Act of 1934, and the
regulations promulgated thereunder, in each case as amended from time to time.

     "EXTENSION OF CREDIT" means (i) the making of a Borrowing (including,
without limitation, any Conversion), (ii) the issuance of a Letter of Credit,
or (iii) the amendment of any Letter of Credit having the effect of extending
the stated termination date thereof, increasing the LC Outstandings
thereunder, or otherwise altering any of the material terms or conditions
thereof.

     "FEDERAL FUNDS RATE" means, for any period, a fluctuating interest rate
per annum equal for each day during such period to the weighted
<PAGE>
 
                                                                            11
average of the rates on overnight Federal funds transactions with members of
the Federal Reserve System arranged by Federal funds brokers, as published for
such day (or, if such day is not a Business Day, for the next preceding
Business Day) by the Federal Reserve Bank of New York, or, if such rate is not
so published for any day which is a Business Day, the average of the quotations
for such day on such transactions received by the Agent from three Federal
funds brokers of recognized standing selected by it.

     "FEE LETTER" means that certain letter agreement, dated November 15, 1996
from Citibank to, and accepted by, the Borrower.

     "FIRST MORTGAGE BONDS" means the bonds issued by Commonwealth pursuant to
the Indenture.

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

     "GOVERNMENTAL APPROVAL" means any authorization, consent, approval,
license, franchise, lease, ruling, tariff, rate, permit, certificate,
exemption of, or filing or registration with, any governmental authority or
other legal or regulatory body required in connection with the execution,
delivery or performance of any Loan Document.

     "GUARANTY" means the Amended and Restated Guaranty, dated as of the date
hereof, by the Parent in favor of the Agent and the Lenders, in substantially
the form of Exhibit E hereto.

     "HAZARDOUS SUBSTANCE" means any waste, substance, or material identified
as hazardous, dangerous or toxic by any office, agency, department,
commission, board, bureau, or instrumentality of the United States or of the
State or locality in which the same is located having or exercising
jurisdiction over such waste, substance or material.

     "INDENTURE" means that certain Mortgage of Commonwealth to Harris Trust
and Savings Bank and D. Donovan (as successors to Bank of America NT & SA and
M.J. Kruge, respectively) as trustees, dated as of July 1, 1923, as the same
has been and may from time to time be amended or supplemented and in effect.

     "INTEREST PERIOD" means, for each Eurodollar Rate Advance made as part of
the same Borrowing, the period commencing on the date of such
<PAGE>
 
                                                                            12

Eurodollar Rate Advance or the date of the Conversion of any Advance into such
Eurodollar Rate Advance and ending on the last day of the period selected by
the Borrower pursuant to the provisions below and, thereafter, each subsequent
period commencing on the last day of the immediately preceding Interest Period
and ending on the last day of the period selected by the Borrower pursuant to
the provisions below.  The duration of each such Interest Period shall be 1, 2,
3 or 6 months, in each case as the Borrower may select, upon notice received by
the Agent not later than 11:00 A.M. on the third Business Day prior to the
first day of such Interest Period; provided, however, that:

          (i)      the Borrower may not select any Interest Period that ends
        after the Termination Date;

          (ii)     Interest Periods commencing on the same date for Eurodollar
        Rate Advances made as part of the same Borrowing shall be of the same
        duration;

          (iii)    if any Interest Period begins on a day for which there is no
        corresponding day in the calendar month during which such Interest
        Period is to end, such Interest Period shall end on the last Business
        Day of such month; and

          (iv)     whenever the last day of any Interest Period would otherwise
        occur on a day other than a Business Day, the last day of such Interest
        Period shall be extended to occur on the next succeeding Business Day,
        provided that if such extension would cause the last day of such
        Interest Period to occur in the next following calendar month, the last
        day of such Interest Period shall occur on the next preceding Business
        Day.

     "LC BANK" means a Lender designated by the Borrower, and acceptable to
the Agent, in accordance with Section 3.01 as the issuer of a Letter of Credit
pursuant to an LC Bank Agreement.

     "LC BANK AGREEMENT" means an agreement between an LC Bank and the
Borrower providing for the issuance of one or more Letters of Credit, in
substantially the form of Exhibit D hereto.

     "LC OUTSTANDINGS" means, for any Letter of Credit on any date of
determination, the maximum amount available to be drawn under such
<PAGE>
 
                                                                            13
Letter of Credit (assuming the satisfaction of all conditions for drawing
enumerated therein).

     "LC PAYMENT NOTICE" has the meaning assigned to that term in Section
3.04(b).

     "LENDER ASSIGNMENT" means an assignment and acceptance agreement entered
into by a Lender and an Eligible Assignee, and accepted by the Agent, in
substantially the form of Exhibit C hereto.

     "LENDERS" means the Banks listed on the signature pages hereof, each
Eligible Assignee that shall become a party hereto pursuant to Section 9.07
and, if and to the extent so provided in Section 3.04(c), each LC Bank.

     "LETTER OF CREDIT" means a letter of credit issued by an LC Bank pursuant
to Section 3.02, as such letter of credit may from time to time be amended,
modified or extended in accordance with the terms of this Agreement and the LC
Bank Agreement to which it relates.

     "LIEN"  has the meaning assigned to that term in Section 6.02(e).

     "LOAN DOCUMENTS" means this Agreement, the Notes, the Guaranty, each LC
Bank Agreement and all other agreements, instruments and documents now or
hereafter executed and delivered pursuant hereto or thereto.

     "MAJORITY LENDERS" means, on any date of determination, Lenders that,
collectively, on such date have in the aggregate at least 66-2/3% of the
Commitments (without giving effect to any termination in whole of the
Commitments pursuant to Section 7.02).  Any determination of those Lenders
constituting the Majority Lenders shall be made by the Agent and shall be
conclusive and binding on all parties, absent manifest error.

     "MATERIAL ADVERSE EFFECT" means, relative to any occurrence of whatever
nature (including, without limitation, any adverse determination in any
litigation, arbitration, or governmental investigation or proceeding), a
material adverse effect on:

                (a)     the consolidated business, assets, revenues, financial
        condition, results of operations, operations, or prospects of the
        Borrower and its Subsidiaries; or
<PAGE>
 
                                                                            14

                (b)     the ability of the Borrower to make any payment when
        due under this Agreement or to perform any of its other obligations
        under the Loan Documents.

     "MOODY'S" means Moody's Investors Service, Inc. or any successor thereto.

     "MULTIEMPLOYER PLAN" means a "multiemployer plan", as such term is
defined in Section 4001(a)(3) of ERISA, that is maintained for employees of
the Borrower or any ERISA Affiliate of the Borrower.

     "NORTHWIND" means Unicom Thermal Technologies Inc., an Illinois
corporation, all of whose common stock is on the date hereof owned by the
Borrower.

     "NOTE"  means a promissory note of the Borrower payable to the order of a
Lender, in substantially the form of Exhibit A hereto, evidencing the
aggregate indebtedness of the Borrower to such Lender resulting from the
Advances made by such Lender.

     "NOTICE OF BORROWING" has the meaning assigned to that term in Section
2.02(a).

     "NOTICE OF CONVERSION" has the meaning assigned to that term in Section
2.10(a).

     "OECD"  means the Organization for Economic Cooperation and Development.

     "PBGC"   means the Pension Benefit Guaranty Corporation (or any successor
entity) established under ERISA.

     "PARENT" means Unicom Corporation, an Illinois corporation.

     "PENSION PLAN" means a "pension plan", as such term is defined in Section
3(2) of ERISA, which is subject to Title IV of ERISA (other than a
Multiemployer Plan), and to which the Borrower or any ERISA Affiliate of the
Borrower may have any liability, including any liability by reason of having
been a substantial employer within the meaning of Section 4063 of ERISA at any
time during the preceding five years, or by reason of being deemed to be a
contributing sponsor under Section 4069 of ERISA.
<PAGE>
 
                                                                            15

     "PERCENTAGE"  means, for any Lender on any date of determination, the
percentage obtained by dividing such Lender's Commitment on such date by the
total of the Commitments on such date (in each case, without giving effect to
any termination of the Commitments pursuant to Section 7.02), and multiplying
the quotient so obtained by 100%.

     "PERSON"   means an individual, partnership, corporation (including a
business trust), joint stock company, trust, unincorporated association, joint
venture or other entity, or a government or any political subdivision or
agency thereof.

     "RATING AGENCY" means D&P, Moody's or S&P.

     "REFERENCE BANKS" means Citibank, Morgan Guaranty Trust Company of New
York and Toronto Dominion (Texas), Inc., or any additional or substitute
Lenders as may be selected from time to time to act as Reference Banks
hereunder by the Agent, the Majority Lenders and the Borrower.

     "REGISTER" has the meaning assigned to that term in Section 9.07(c).

     "REQUEST FOR ISSUANCE" has the meaning assigned to that term in Section
3.02(a).

     "S&P" means Standard & Poor's Ratings Group or any successor thereto.

     "SEC"  means the Securities and Exchange Commission and any entity
succeeding to its functions under the Securities Act of 1933, as amended, or
the Exchange Act.

     "SIGNIFICANT SUBSIDIARY" means Northwind and any other Subsidiary of the
Borrower that, on a consolidated basis with any of its Subsidiaries as of any
date of determination, accounts for more than 20% of the consolidated assets
(valued at book value) of the Borrower and its Subsidiaries.

     "SUBSIDIARY"  means, with respect to any Person, any corporation or
unincorporated entity of which more than 50% of the outstanding capital stock
(or comparable interest) having ordinary voting power (irrespective of whether
at the time capital stock (or comparable interest)
<PAGE>
 
                                                                            16
of any other class or classes of such corporation or entity shall or might have
voting power upon the occurrence of any contingency) is at the time directly or
indirectly owned by said Person (whether directly or through one of more other
Subsidiaries). In the case of an unincorporated entity, a Person shall be
deemed to have more than 50% of interests having ordinary voting power only if
such Person's vote in respect of such interests comprises more than 50% of the
total voting power of all such interests in the unincorporated entity.

     "TERMINATION DATE" means the earlier to occur of (i) the third
anniversary of the date hereof or such later date to which the Termination
Date is extended in accordance with Section 2.18, and (ii) the date of
termination or reduction in whole of the Commitments pursuant to Section 2.05
or 7.02.

     "TYPE"  has the meaning assigned to that term (i) in the definition of
"Advance" when used in such context and (ii) in the definition of "Borrowing"
when used in such context.

     "UNMATURED DEFAULT" means an event that, with the giving of notice or
lapse of time, or both, would constitute an Event of Default.

     "WELFARE PLAN" means a "welfare plan", as such term is defined in Section
3(1) of ERISA.

     SECTION 1.02.  COMPUTATION OF TIME PERIODS.  Unless otherwise indicated,
each reference in this Agreement to a specific time of day is a reference to
New York City time.  In the computation of periods of time under this
Agreement, any period of a specified number of days or months shall be
computed by including the first day or month occurring during such period and
excluding the last such day or month.  In the case of a period of time "from"
a specified date "to" or "until" a later specified date, the word "from" means
"from and including" and the words "to" and "until" each means "to but
excluding".

     SECTION 1.03.  ACCOUNTING TERMS.  All accounting terms not specifically
defined herein shall be construed in accordance with GAAP.
<PAGE>
 
                                                                            17
                                   ARTICLE II
                       AMOUNTS AND TERMS OF THE ADVANCES

     SECTION 2.01.   THE ADVANCES.  (a) Each Lender severally agrees, on the
terms and conditions hereinafter set forth, to make Advances to the Borrower
and to participate in the issuance of Letters of Credit (and the LC
Outstandings thereunder) from time to time on any Business Day during the
period from the Effective Date until the Termination Date in an aggregate
amount not to exceed on any day such Lender's Available Commitment (after
giving effect to all Extensions of Credit to be made on such day and the
application of the proceeds thereof).  Each Borrowing (other than a Borrowing
deemed made under Section 3.04(d)) shall be in an aggregate amount not less
than $5,000,000, or an integral multiple of $1,000,000 in excess thereof (or
such lesser amount as shall be equal to the total amount of the Available
Commitments on such date, after giving effect to all other Extensions of
Credit to be made on such date), and shall consist of Advances of the same
Type, having the same Interest Period (in the case of Eurodollar Rate
Advances) and made or Converted on the same day by the Lenders ratably
according to their respective Percentages.  Within the limits of each Lender's
Commitment and subject to the conditions hereinafter set forth, the Borrower
may request Extensions of Credit hereunder, prepay Advances, or reduce or
cancel Letters of Credit, and use the resulting increase in the Available
Commitments for further Extensions of Credit in accordance with the terms
hereof.

     (b)     In no event shall the Borrower be entitled to request or receive
any Extensions of Credit that would cause the principal amount outstanding
hereunder to exceed the Commitments.

     SECTION 2.02.  MAKING THE ADVANCES.   (a) Each Borrowing shall be made on
notice, given not later than 10:30 A.M., in the case of Alternate Base Rate
Advances, or 11:30 A.M., in the case of Eurodollar Rate Advances,  (i) on the
third Business Day prior to the date of the proposed Borrowing, in the case of
a Borrowing comprised of Eurodollar Rate Advances, and (ii) on the date of the
proposed Borrowing, in the case of a Borrowing comprised of Alternate Base
Rate Advances, in each case by the Borrower to the Agent, which shall give to
each Lender prompt notice thereof by telecopier, telex, or cable.  Each such
notice of a Borrowing (a "NOTICE OF BORROWING") shall be by telecopier, telex
or cable, in substantially the form of Exhibit B-1 hereto, specifying therein
the requested (A) date of such Borrowing, (B) Type of Advances comprising such
Borrowing, (C) aggregate amount of such Borrowing, and (D) in the case of a
Borrowing comprised of Eurodollar Rate Advances, the Interest Period for each
such Advance.  Each Lender shall, before 12:00 noon on the date of such
Borrowing,
<PAGE>
 
                                                                            18

make available for the account of its Applicable Lending Office to the Agent at
its address referred to in Section 9.02, in same day funds, such Lender's
ratable portion of such Borrowing.  After the Agent's receipt of such funds and
upon fulfillment of the applicable conditions set forth in Article IV, the
Agent will make such funds available to the Borrower at the Agent's aforesaid
address.

     (b)     Each Notice of Borrowing shall be irrevocable and binding on the
Borrower.  In the case of any Borrowing which the related Notice of Borrowing
specifies is to be comprised of Eurodollar Rate Advances, the Borrower shall
indemnify each Lender against any loss, cost or expense incurred by such
Lender as a result of any failure to fulfill, on or before the date specified
in such Notice of Borrowing for such Borrowing, the applicable conditions set
forth in Article IV, including, without limitation, any loss, cost, or expense
incurred by reason of the liquidation or reemployment of deposits or other
funds acquired by such Lender to fund the Advance to be made by such Lender as
part of such Borrowing when such Advance, as a result of such failure, is not
made on such date.

     (c)     Unless the Agent shall have received notice from a Lender prior
to the date of any Borrowing that such Lender will not make available to the
Agent such Lender's Advance as part of such Borrowing, the Agent may assume
that such Lender has made such Advance available to the Agent on the date of
such Borrowing in accordance with subsection (a) of this Section 2.02 and the
Agent may, in reliance upon such assumption, make available to the Borrower on
such date a corresponding amount.  If and to the extent that such Lender shall
not have so made such Advance available to the Agent, such Lender and the
Borrower severally agree to repay to the Agent forthwith on demand such
corresponding amount, together with interest thereon for each day from the
date such amount is made available to the Borrower until the date such amount
is repaid to the Agent, at (i) in the case of the Borrower, the interest rate
applicable at the time to Advances comprising such Borrowing and (ii) in the
case of such Lender, the Federal Funds Rate.  If such Lender shall repay to
the Agent such corresponding amount, such amount so repaid shall constitute
such Lender's Advance as part of such Borrowing for purposes of this
Agreement.

     (d)     The failure of any Lender to make the Advance to be made by it as
part of any Borrowing shall not relieve any other Lender of its obligation, if
any, hereunder to make its Advance on the date of such Borrowing, but no
Lender shall be responsible for the failure of any other Lender to make the
Advance to be made by such other Lender on the date of any Borrowing.
<PAGE>
 
                                                                            19

     (e)     Notwithstanding anything contained herein to the contrary,  (i)
not more than two Borrowings may be made on the same Business Day and (ii) not
more than seven Borrowings may be outstanding at any one time.

     SECTION 2.03.  COMPUTATIONS OF OUTSTANDINGS.  Whenever reference is made
in this Agreement to the principal amount outstanding on any date under this
Agreement, such reference shall refer to the sum of (i) the aggregate
principal amount of all Advances outstanding on such date plus (ii) the
aggregate LC Outstandings of all Letters of Credit outstanding on such date,
in each case after giving effect to all Extensions of Credit to be made on
such date and the application of the proceeds thereof.  References to the
unused portion of the Commitments shall refer to the excess, if any, of the
Commitments over the principal amount outstanding hereunder; and references to
the unused portion of any Lender's Commitment shall refer to such Lender's
Percentage of the unused Commitments.

     SECTION 2.04.  FEES.   (a) The Borrower agrees to pay to the Agent for the
account of each Lender the Commitment Fee from the date hereof, in the case of
each Bank, and from the effective date specified in the Lender Assignment
pursuant to which it became a Lender, in the case of each other Lender, until
the Termination Date, payable quarterly in arrears on the last day of each
March, June, September and December during the term of such Lender's
Commitment, commencing on the first such date to occur following the date
hereof, and on the Termination Date.

     (b)     The Borrower agrees to pay to the Agent for the account of each
Lender a commission on such Lender's Percentage of the average daily aggregate
amount of the LC Outstandings from the date hereof until the Termination Date
at a rate per annum equal to the Applicable Margin with respect to Eurodollar
Rate Advances from time to time, payable quarterly in arrears on the last day
of each March, June, September and December, commencing on the first such date
to occur following the date hereof, and on the Termination Date.

     (c)     In addition to the fees provided for in subsections (a) and (b)
above, the Borrower shall pay to the Agent, for the account of the Agent, such
other fees as are provided for in the Fee Letter, at the times and in the
manner set forth therein.

     SECTION 2.05.  REDUCTION OF THE COMMITMENTS.  The Borrower shall have the
right, upon at least three Business Days' notice to the Agent, to terminate in
whole or reduce ratably in part the unused portions of the respective
Commitments of the Lenders; provided that the aggregate amount of the
Commitments of the
<PAGE>
 
                                                                            20

Lenders shall not be reduced to an amount that is less than the aggregate
principal amount then outstanding hereunder; and provided, further, that each
partial reduction shall be in an aggregate amount equal to $5,000,000 and an
integral multiple of $1,000,000 in excess thereof.

     SECTION 2.06.  REPAYMENT OF ADVANCES.  The Borrower shall repay the
principal amount of each Advance made by each Lender in accordance with the
Note to the order of such Lender; provided, however, that the aggregate
principal amount outstanding of all Advances made by a Lender shall be due and
payable in full on the Termination Date.

     SECTION 2.07.  INTEREST ON ADVANCES.  The Borrower shall pay interest on
the unpaid principal amount of each Advance owing to each Lender from the date
of such Advance until such principal amount shall be paid in full, at the
Applicable Rate for such Advance (except as otherwise provided in this Section
2.07), payable as follows:

              (a)     ALTERNATE BASE RATE ADVANCES.  If such Advance is an
        Alternate Base Rate Advance, interest thereon shall be payable
        quarterly in arrears on the last day of each March, June, September and
        December, on the date of any Conversion of such Alternate Base Rate
        Advance and on the date such Alternate Base Rate Advance shall become
        due and payable or shall otherwise be paid in full; provided that any
        amount of principal that is not paid when due (whether at stated
        maturity, by acceleration, or otherwise) shall bear interest, from the
        date on which such amount is due until such amount is paid in full,
        payable on demand, at a rate per annum equal at all times to the
        Default Rate.

              (b)     EURODOLLAR RATE ADVANCES.  Subject to Section 2.08, if
        such Advance is a Eurodollar Rate Advance, interest thereon shall be
        payable on the last day of each Interest Period and, if the Interest
        Period for such Advance has a duration of six months, on the
        numerically corresponding day that occurs during such Interest Period
        three months from the first day of such Interest Period (or, if any
        such month does not have a numerically corresponding day, then on the
        last day of such month) and on the date such Eurodollar Rate Advance
        shall be Converted, shall become due and payable or shall otherwise be
        paid in full; provided that any amount of principal that is not paid
        when due (whether at stated maturity, by acceleration, or otherwise)
        shall bear interest, from the date on which such amount is due until
        such amount is paid in full, payable on demand, at a rate per annum
        equal at all times to the Default Rate.
<PAGE>
 
                                                                            21

     SECTION 2.08.  ADDITIONAL INTEREST ON EURODOLLAR ADVANCES. The Borrower
shall pay to the Agent for the account of each Lender any costs actually
incurred by such Lender which are attributable to such Lender's compliance
with regulations of the Board of Governors of the Federal Reserve System
requiring the maintenance of reserves with respect to liabilities or assets
consisting of or including Eurocurrency Liabilities.  Such costs shall be paid
to the Agent for the account of such Lender in the form of additional interest
on the unpaid principal amount of each Eurodollar Rate Advance of such Lender,
from the date of such Advance until such principal amount is paid in full, at
an interest rate per annum equal at all times to the remainder obtained by
subtracting  (i) the Eurodollar Rate for the Interest Period for such Advance
from (ii) the rate obtained by dividing such Eurodollar Rate by a percentage
equal to 100% minus the Eurodollar Reserve Percentage of such Lender for such
Interest Period, payable on each date on which interest is payable on such
Advance.  Such additional interest shall be determined by such Lender and
notified to the Borrower through the Agent.  A certificate as to the amount of
such additional interest, submitted to the Borrower and the Agent by such
Lender, shall be conclusive and binding for all purposes, absent manifest
error.

     SECTION 2.09.  INTEREST RATE DETERMINATION.   (a) Each Reference Bank
agrees to furnish to the Agent timely information for the purpose of
determining each Eurodollar Rate.  If any one or more of the Reference Banks
shall not furnish such timely information to the Agent for the purpose of
determining any such interest rate, the Agent shall determine such interest
rate on the basis of timely information furnished by the remaining Reference
Banks.

     (b)     The Agent shall give prompt notice to the Borrower and the
Lenders of the applicable interest rate determined by the Agent for purposes
of Section 2.07(a) or (b) and the applicable rate, if any, furnished by each
Reference Bank for the purpose of determining the applicable interest rate
under Section 2.07(b).

     (c)     If fewer than two Reference Banks furnish timely information to
the Agent for determining the Eurodollar Rate for any Eurodollar Rate
Advances, due to the unavailability of funds to such Reference Banks in the
relevant financial markets:

                (i)     the Agent shall forthwith notify the Borrower and the
        Lenders that the interest rate cannot be determined for such Eurodollar
        Rate Advances;
<PAGE>
 
                                                                            22

                (ii)     each such Advance will automatically, on the last day
        of the then existing Interest Period therefor, Convert into an
        Alternate Base Rate Advance (or if such Advance is then an Alternate
        Base Rate Advance, will continue as an Alternate Base Rate Advance);
        and

                (iii)     the obligation of the Lenders to make, or to Convert
        Advances into, Eurodollar Rate Advances, shall be suspended until the
        Agent shall notify the Borrower and the Lenders that the circumstances
        causing such suspension no longer exist.

     (d)     If, with respect to any Eurodollar Rate Advances, the Majority
Lenders notify the Agent that the Eurodollar Rate for any Interest Period for
such Advances will not adequately reflect the cost to such Majority Lenders of
making, funding, or maintaining their respective Eurodollar Rate Advances for
such Interest Period, the Agent shall forthwith so notify the Borrower and the
Lenders, whereupon:

                (i)      each Eurodollar Rate Advance will automatically, on the
        last day of the then existing Interest Period therefor, Convert into an
        Alternate Base Rate Advance; and

                (ii)     the obligation of the Lenders to make, or to Convert
        Advances into, Eurodollar Rate Advances shall be suspended until the
        Agent shall notify the Borrower and the Lenders that the circumstances
        causing such suspension no longer exist.

     (e)     If the Borrower shall fail to select the duration of any Interest
Period for any Eurodollar Rate Advances in accordance with the provisions
contained in the definition of "INTEREST PERIOD" in Section 1.01, the Agent
will forthwith so notify the Borrower and the Lenders and such Advances will
automatically, on the last day of the then existing Interest Period therefor,
Convert into Alternate Base Rate Advances.

     (f)     On the date on which the aggregate unpaid principal amount of
Advances comprising all Borrowings shall be reduced, by payment or prepayment
or otherwise, to less than $5,000,000, such Advances shall, if they are
Eurodollar Rate Advances, automatically Convert into Alternate Base Rate
Advances, and on and after such date the right of the Borrower to Convert such
Advances into Eurodollar Rate Advances shall be suspended until such time that
the aggregate unpaid principal amount of Advances comprising all Borrowings
shall equal or exceed $5,000,000.

<PAGE>
 
                                                                            23

     SECTION 2.10.  CONVERSION OF ADVANCES.  So long as no Event of Default or
Unmatured Default shall have occurred and be continuing, the Borrower may on
any Business Day, by delivering a notice of Conversion (a "Notice of
Conversion") to the Agent not later than 12:00 noon  (i) on the third Business
Day prior to the date of the proposed Conversion, in the case of a Conversion
to Eurodollar Rate Advances and (ii) on the date of the proposed Conversion, in
the case of a Conversion to Alternate Base Rate Advances, and subject to the
provisions of Sections 2.09 and 2.13, Convert all Advances of one Type
comprising the same Borrowing into Advances of another Type; provided,
however, that, in the case of any Conversion of any Eurodollar Rate Advances
into Advances of another Type on a day other than the last day of an Interest
Period for such Eurodollar Rate Advances, the Borrower shall be obligated to
reimburse the Lenders in respect thereof pursuant to Section 9.04(b).  Each
such Notice of Conversion shall be in substantially the form of Exhibit B-2
hereto and shall, within the restrictions specified above, specify (A) the
date of such Conversion, (B) the Advances to be Converted, (C) if such
Conversion is into Eurodollar Rate Advances, the duration of the Interest
Period for each such Advance, and (D) the aggregate amount of Advances
proposed to be Converted.

     SECTION 2.11.  OPTIONAL PREPAYMENTS OF ADVANCES.  The Borrower may, upon
at least three Business Days' notice to the Agent stating the proposed date
and aggregate principal amount of the prepayment, and if such notice is given
the Borrower shall, prepay the outstanding principal amounts of the Advances
comprising part of the same Borrowing in whole or ratably in part, together
with accrued interest to the date of such prepayment on the principal amount
prepaid; provided, however, that (i) each partial prepayment shall be in an
aggregate principal amount not less than $5,000,000 or an integral multiple of
$1,000,000 in excess thereof and (ii) in the case of any such prepayment of
Eurodollar Rate Advances, the Borrower shall be obligated to reimburse the
Lenders in respect thereof pursuant to Section 9.04(b) on the date of such
prepayment.  Except as provided in this Section 2.11, the Borrower shall have
no right to prepay any principal amount of any Advances.

     SECTION 2.12.  MANDATORY PREPAYMENTS.   (a) If and to the extent that the
aggregate principal amount outstanding on any date hereunder shall exceed the
aggregate amount of the Commitments hereunder on such date, the Borrower shall
pay or prepay for the ratable accounts of the Lenders so much of the principal
amount outstanding under this Agreement as shall be necessary in order that
the principal amount outstanding (after giving effect to such prepayment) will
not exceed the amount of Commitments on such date, together with (i) accrued
interest to the date of such prepayment on the principal amount repaid or
prepaid
<PAGE>
 
                                                                            24

and (ii) in the case of prepayments of Eurodollar Rate Advances, any amount
payable to the Lenders pursuant to Section 9.04(b).

     (b)     All prepayments required to be made pursuant to subsection (a),
above, shall be applied by the Agent:

                (i)     first, to the prepayment in whole or ratably in part of
        the principal amount of all outstanding Alternate Base Rate Advances
        (without reference to minimum dollar requirements);

               (ii)     second, to the prepayment in whole or ratably in part
        of the principal amount of all outstanding Eurodollar Rate Advances
        (without reference to minimum dollar requirements); and

              (iii)     third, to the cash collateralization of LC Outstandings
        by depositing such amounts in a special interest-bearing escrow account
        maintained by the Agent at the Agent's office and pledged to the Agent
        for the benefit of the Lenders pursuant to documentation reasonably
        satisfactory to the Borrower and the Agent.

     (c)     In lieu of prepaying any Eurodollar Rate Advances under any
provision (other than Sections 2.14 and 7.02) of this Agreement, the Borrower
may, upon notice to the Agent, deliver such funds to the Agent, to be held as
additional cash collateral securing the obligations hereunder and under the
Notes.  The Agent shall deposit all amounts delivered to it in a
non-interest-bearing special purpose cash collateral account, to be governed
by a cash collateral agreement in form and substance satisfactory to the
Borrower and the Agent, and shall apply all such amounts in such account
against such Advances, and such Advances shall be deemed prepaid, on the last
day of the Interest Period therefor.  The Agent shall promptly notify the
Lenders of any election by the Borrower to deliver funds to the Agent under
this subsection (c).

     SECTION 2.13.  INCREASED COSTS.  (a) If, due to either  (i) the
introduction of or any change (other than any change by way of imposition or
increase of reserve requirements, in the case of Eurodollar Rate Advances,
included in the Eurodollar Reserve Percentage) in or in the interpretation of
any law or regulation or (ii) the compliance with any guideline or request from
any central bank or other governmental authority (whether or not having the
force of law), there shall be any increase in (A) the cost to any Lender of
agreeing to make or making, funding or maintaining Eurodollar Rate Advances,
or of participating in the issuance, maintenance or funding of any Letter of
Credit, or (B) the cost to any LC Bank of issuing, maintaining or funding any
Letter of Credit, then the Borrower shall
<PAGE>
 
                                                                            25

from time to time, upon demand by such Lender or any LC Bank, as the case may
be (with a copy of such demand to the Agent), pay to the Agent for the account
of such Lender or LC Bank, as the case may be, additional amounts sufficient to
compensate such Lender or LC Bank, as the case may be, for such increased cost.
A certificate as to the amount of such increased cost, submitted to the
Borrower and the Agent by such Lender or LC Bank, shall be conclusive and
binding for all purposes, absent manifest error.

     (b)     If any Lender or LC Bank determines that compliance with any law
or regulation or any guideline or request from any central bank or other
governmental authority (whether or not having the force of law) affects or
would affect the amount of capital required or expected to be maintained by
such Lender or LC Bank or any corporation controlling such Lender or LC Bank
and that the amount of such capital is increased by or based upon (1) the
existence of such Lender's or LC Bank's commitment to lend or issue or
participate in any Letter of Credit hereunder or (2) the participation in or
issuance or maintenance of any Letter of Credit or Advance and (3) other
similar such commitments, then, upon demand by such Lender or LC Bank (with a
copy of such demand to the Agent), the Borrower shall immediately pay to the
Agent for the account of such Lender or LC Bank from time to time as specified
by such Lender or LC Bank additional amounts sufficient to compensate such
Lender or LC Bank or such corporation in the light of such circumstances, to
the extent that such Lender or LC Bank reasonably determines such increase in
capital to be allocable to the transactions contemplated hereby.  A
certificate as to such amounts submitted to the Borrower and the Agent by such
Lender or LC Bank, describing in reasonable detail the manner in which such
amounts have been calculated, shall be conclusive and binding for all
purposes, absent manifest error.

     (c)     Notwithstanding the provisions of subsection (a) or (b), above,
to the contrary, no Lender or LC Bank shall be entitled to demand compensation
or be compensated thereunder to the extent that such compensation relates to
any period of time more than 180 days prior to the date upon which such Lender
or LC Bank first notified the Borrower of the occurrence of the event
entitling such Lender to such compensation (unless, and to the extent, that
any such compensation so demanded shall relate to the retroactive application
of any event so notified to the Borrower).

     SECTION 2.14.  ILLEGALITY.  Notwithstanding any other provision of this
Agreement to the contrary, if any Lender (the "AFFECTED LENDER") shall notify
the Agent and the Borrower that the introduction of or any change in or in the
interpretation of any law or regulation makes it unlawful, or any central bank
or other governmental authority asserts that it is unlawful, for the Affected
Lender
<PAGE>
 
                                                                            26
or its Eurodollar Lending Office to perform its obligations hereunder to make
Eurodollar Rate Advances or to fund or maintain Eurodollar Rate Advances
hereunder,  (i) all Eurodollar Rate Advances of the Affected Lender shall, on
the fifth Business Day following such notice from the Affected Lender (or
sooner if required by such law, regulation, central bank or other governmental
authority), automatically be Converted into a like number of Alternate Base
Rate Advances, each in the amount of the corresponding Eurodollar Rate Advance
of the Affected Lender being so Converted (each such Advance, as so Converted,
being an "AFFECTED LENDER ADVANCE"), and the obligation of the Affected Lender
to make, maintain, or Convert Advances into Eurodollar Rate Advances shall
thereupon be suspended until the Agent shall notify the Borrower and the
Lenders that the circumstances causing such suspension no longer exist, or the
Affected Lender has been replaced pursuant to Section 9.07(g), and (ii) in the
event that, on the last day of each of the then-current Interest Periods for
each Eurodollar Rate Advance (each such Advance being an "UNAFFECTED LENDER
ADVANCE") of each of the other Lenders (each such Lender being an "UNAFFECTED
LENDER"), the Agent shall have yet to notify the Borrower and the Lenders that
the circumstances causing such suspension of the Affected Lender's obligations
as aforesaid no longer exist, or the Affected Lender has not yet been replaced
pursuant to Section 9.07(g), such Unaffected Lender Advances shall be Converted
into Alternate Base Rate Advances, and the obligation of each such Unaffected
Lender to make, maintain, or Convert Advances into Eurodollar Rate Advances
shall be suspended until the Agent shall so notify the Borrower and the
Lenders, or the Affected Lender shall be so replaced.  For purposes of any
prepayment under this Agreement, each Affected Lender Advance shall be deemed
to continue to be part of the same Borrowing as the Unaffected Lender Advances
to which it corresponded at the time of the Conversion of such Affected Lender
Advance pursuant to clause (i), above.

     SECTION 2.15.  PAYMENTS AND COMPUTATIONS.    (a) The Borrower shall make
each payment hereunder and under the Notes not later than 1:00 P.M. on the day
when due in Dollars to the Agent at its address referred to in Section 9.02 in
same day funds.  Any payment that is received by the Agent after 1:00 P.M. on
any Business Day shall be deemed received on the immediately succeeding
Business Day.  The Agent will promptly thereafter cause to be distributed like
funds relating to the payment of principal or interest or fees ratably (other
than amounts payable pursuant to Section 2.02(c), 2.04(c), 2.08, 2.13, 2.16,
9.04(b) or 9.04(c)) (in accordance with their respective Percentages) to the
Lenders for the account of their respective Applicable Lending Offices, and
like funds relating to the payment of any other amount payable to any Lender
to such Lender for the account of its Applicable Lending Office, in each case
to be applied in accordance with the terms of this Agreement.  Upon its
acceptance of a Lender Assignment
<PAGE>
 
                                                                            27

and recording of the information contained therein in the Register pursuant to
Section 9.07(d), from and after the effective date specified in such Lender
Assignment, the Agent shall make all payments hereunder and under the Notes in
respect of the interest assigned thereby to the Lender assignee thereunder, and
the parties to such Lender Assignment shall make all appropriate adjustments in
such payments for periods prior to such effective date directly between
themselves.

     (b)     The Borrower hereby authorizes each Lender and LC Bank, if and to
the extent payment owed to such Lender or LC Bank is not made when due
hereunder or under any Note held by such Lender, to charge from time to time
against any or all of the Borrower's accounts with such Lender or LC Bank, as
the case may be, any amount so due.

     (c)     All computations of interest based on the Alternate Base Rate and
of fees shall be made by the Agent on the basis of a year of 365 or 366 days,
as the case may be, and all computations of interest based on the Eurodollar
Rate and the Federal Funds Rate shall be made by the Agent, and all
computations of interest pursuant to Section 2.08 shall be made by a Lender,
on the basis of a year of 360 days, in each case for the actual number of days
(including the first day but excluding the last day) occurring in the period
for which such interest or fees are payable.  Each determination by the Agent
(or, in the case of Section 2.08, by a Lender) of an interest rate hereunder
shall be conclusive and binding for all purposes, absent manifest error.

     (d)     Whenever any payment hereunder, under the Notes, under an LC Bank
Agreement or under any other Loan Document shall be stated to be due on a day
other than a Business Day, such payment shall be made on the next succeeding
Business Day, and such extension of time shall in such case be included in the
computation of payment of interest or fees, as the case may be; provided,
however, that if such extension would cause payment of interest on or
principal of Eurodollar Rate Advances to be made in the next following
calendar month, such payment shall be made on the next preceding Business Day,
and such reduction of time shall in such case be taken into account in the
computation of interest or fees, as the case may be.

     (e)     Unless the Agent shall have received notice from the Borrower
prior to the date on which any payment is due to the Lenders hereunder that the
Borrower will not make such payment in full, the Agent may assume that the
Borrower has made such payment in full to the Agent on such date and the Agent
may, in reliance upon such assumption, cause to be distributed to each Lender
on such due date an amount equal to the amount then due such Lender.  If and to
the extent that the Borrower shall not have so made such payment in full to the
<PAGE>
 
                                                                            28

Agent, each Lender shall repay to the Agent forthwith on demand such amount
distributed to such Lender together with interest thereon, for each day from
the date such amount is distributed to such Lender until the date such Lender
repays such amount to the Agent, at the Federal Funds Rate.

     (f)     Notwithstanding anything to the contrary contained herein, any
amount payable by the Borrower hereunder or under any Note that is not paid
when due (whether at stated maturity, by acceleration or otherwise) shall (to
the fullest extent permitted by law) bear interest from the date when due
until paid in full at a rate per annum equal at all times to the Default Rate,
payable upon demand.

     SECTION 2.16.  TAXES.   (a) Any and all payments by the Borrower
hereunder and under the other Loan Documents shall be made, in accordance with
Section 2.15, free and clear of and without deduction for any and all present
or future taxes, levies, imposts, deductions, charges, or withholdings, and
all liabilities with respect thereto, excluding, in the case of each Lender,
each LC Bank and the Agent, taxes imposed on its overall net income and
franchise taxes imposed on it by the jurisdiction under the laws of which such
Lender, LC Bank or the Agent (as the case may be) is organized or any
political subdivision thereof and, in the case of each Lender, taxes imposed
on its overall net income and franchise taxes imposed on it by the
jurisdiction of such Lender's Applicable Lending Office or any political
subdivision thereof (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 other Loan Document to
any Lender, any LC Bank or the Agent,  (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 2.16) such
Lender, such LC Bank or the Agent (as the case may be) 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 pay the
full amount deducted to the relevant taxation authority or other authority in
accordance with applicable law.

     (b)     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 under any other
Loan Document or from the execution, delivery or registration of, or otherwise
with respect to, this Agreement or any other Loan Document (hereinafter
referred to as "OTHER TAXES").
<PAGE>
 
                                                                            29

     (c)     The Borrower will indemnify each Lender, each LC Bank and the
Agent 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 2.16) paid by such Lender, such LC Bank or the
Agent (as the case may be) 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 such Lender, such LC Bank or the
Agent (as the case may be) makes written demand therefor.

     (d)     Within 30 days after the date of any payment of Taxes, the
Borrower will furnish to the Agent, at its address referred to in Section
9.02, the original or a certified copy of a receipt evidencing payment
thereof.

     (e)     Each Lender which is organized under the laws of a jurisdiction
outside of the United States agrees that, on or prior to the date upon which
it shall become a party hereto, and upon the reasonable request from time to
time of the Borrower or the Agent, such Lender will deliver to the Borrower
and the Agent duly completed copies of such form or forms as may from time to
time be prescribed by the United States Internal Revenue Service indicating
that such Lender is entitled to receive payments without deduction or
withholding of any United States Federal income taxes, as permitted by the
Code.  Each Lender that delivers to the Borrower and the Agent the form or
forms referred to in the preceding sentence further undertakes to deliver to
the Borrower and the Agent further copies of such form or forms, or successor
applicable form or forms, as the case may be, as and when any previous form
filed by it hereunder shall expire or shall become incomplete or inaccurate in
any respect, unless such Lender is no longer permitted under United States law
to deliver such form or forms.  Each such Lender represents and warrants that
each such form supplied by it to the Agent and the Borrower pursuant to this
subsection (e), and not superseded by another form supplied by it, is or will
be, as the case may be, complete and accurate.

     (f)     Any Lender claiming any additional amounts payable pursuant to
this Section 2.16 shall use its best efforts (consistent with its internal
policy and legal and regulatory restrictions) to change the jurisdiction of
its Applicable Lending Office if the making of such a change would avoid the
need for, or reduce the amount of, any such additional amounts which may
thereafter accrue and would not, in the reasonable judgment of such Lender, be
otherwise disadvantageous to such Lender.
            
<PAGE>
 
                                                                            30

     (g)     Without prejudice to the survival of any other agreement of the
Borrower hereunder, the agreements and obligations of the Borrower contained
in this Section 2.16 shall survive the payment in full of principal and
interest hereunder and under the Notes.

     SECTION 2.17.  SHARING OF PAYMENTS, ETC.   If any Lender shall obtain any
payment (whether voluntary, involuntary, through the exercise of any right of
set-off, or otherwise) on account of the Advances made by it (other than
pursuant to Section 2.02(c), 2.08, 2.16, 9.04(b) or 9.07) in excess of its
ratable share of payments on account of the Advances obtained by all the
Lenders, such Lender shall forthwith purchase from the other Lenders such
participations in the Advances made by them as shall be necessary to cause
such purchasing Lender to share the excess payment ratably with each of them;
provided, however, that if all or any portion of such excess payment is
thereafter recovered from such purchasing Lender, such purchase from each
Lender shall be rescinded and such Lender shall repay to the purchasing Lender
the purchase price to the extent of such recovery, together with an amount
equal to such Lender's ratable share (according to the proportion of (i) the
amount of such Lender's required repayment to (ii) the total amount so
recovered from the purchasing Lender) of any interest or other amount paid or
payable by the purchasing Lender in respect of the total amount so recovered.
The Borrower agrees that any Lender so purchasing a participation from another
Lender pursuant to this Section 2.17 may, to the fullest extent permitted by
law, exercise all its rights of payment (including the right of set-off) with
respect to such participation as fully as if such Lender were the direct
creditor of the Borrower in the amount of such participation.

     SECTION 2.18.  EXTENSION OF TERMINATION DATE.   (a) At least 60 but not
more than 90 days before each anniversary of the date of this Agreement, the
Borrower may, by delivering a written request to the Agent (each such request
being irrevocable), request that each Lender extend for one year the
Termination Date.  The Agent shall, upon its receipt of such a request,
promptly notify each Lender thereof, and request that each Lender promptly
advise the Agent of its approval or rejection of such request.

     (b)     Upon receipt of such notification from the Agent, each Lender may
(but shall not be required to), in its sole and absolute discretion, agree to
extend the Termination Date with respect to its Commitment for a period of one
year, and shall (should it determine to do so), no later than 30 days
following its receipt of such notification, notify the Agent of its approval
concerning such request.  If any Lender shall not so notify the Agent, such
Lender shall be deemed not to have consented to such request.  The Agent shall
thereupon notify the Borrower as to the Lenders, if any, that have consented
to such request.
<PAGE>
 
                                                                            31

     (c)     If such request shall have been consented to by all the Lenders
(as determined after giving effect to the replacement of any Lender pursuant
to Section 9.07(g)), the Agent shall notify the Borrower in writing of such
consent, and such extension shall become effective upon the delivery by the
Borrower to the Agent and each Lender, on or prior to the then-effective
Termination Date, of (i) a certificate of a duly authorized officer of the
Borrower, dated such date, as to the accuracy, both before and after giving
effect to such proposed extension, of the representations and warranties set
forth in Section 5.01 and as to the absence, both before and after giving
effect to such proposed extension, of any Event of Default or any Unmatured
Default, (ii) certified copies of all corporate and governmental approvals, if
any, required to be obtained by the Borrower or the Parent in connection with
such extension and (iii) an opinion or opinions of counsel to the Borrower and
the Parent as to the matters set forth in paragraphs 1, 2, 3, 5, 6 and 8 of
Exhibit F after giving effect to such extension and such other matters as any
Lender, through the Agent, may reasonably request.

     SECTION 2.19.  ADVANCES OUTSTANDING UNDER EXISTING CREDIT AGREEMENT.  The
Agent, the Lenders and the Borrowers each hereby acknowledges and agrees that
any and all "Advances" outstanding under the Credit Agreement dated as of
November 22, 1994 among the Borrower, the banks named therein and Citibank,
N.A., as agent, shall constitute and be deemed for all purposes an Advance
outstanding under this Agreement and the Notes.

                                  ARTICLE III
                               LETTERS OF CREDIT

     SECTION 3.01.  LC BANKS.   (a) Subject to the terms and conditions hereof,
the Borrower may from time to time arrange for one or more Lenders to act as
an LC Bank hereunder.  Any such designation by the Borrower shall be notified
to the Agent at least five Business Days prior to the first date upon which
the Borrower proposes that such LC Bank issue its first Letter of Credit, so
as to provide adequate time for such proposed Letter of Credit to be approved
by the Agent hereunder; provided, that nothing contained herein shall be
deemed to require any Lender to agree to act as an LC Bank, if it does not so
desire.  Within two Business Days following the receipt of any such
designation of a proposed LC Bank together with the proposed form of such
Letter of Credit, the Agent shall notify the Borrower as to whether such
Letter of Credit complies with the requirements specified therefor in this
Agreement.

     (b)     The aggregate amount of all LC Outstandings in respect of all
Letters of Credit outstanding on any date of determination shall not exceed
$100,000,000.
<PAGE>
 
                                                                            32

     SECTION 3.02.  LETTERS OF CREDIT.  (a) Each Letter of Credit shall be
issued (or the stated maturity thereof extended or terms thereof modified or
amended) on not less than three Business Days' prior written notice thereof to
the Agent (which shall promptly distribute copies thereof to the Lenders) and
the relevant LC Bank.  Each such notice (a "REQUEST FOR ISSUANCE") shall
specify (i) the date (which shall be a Business Day) of issuance of such
Letter of Credit (or the date of effectiveness of such extension, modification
or amendment) and the stated expiry date thereof (which shall be no later than
the then-scheduled Termination Date), (ii) the proposed stated amount of such
Letter of Credit (which shall not be less than $1,000,000) and (iii) such
other information as shall demonstrate compliance by such Letter of Credit
with the requirements specified therefor in this Agreement and the relevant LC
Bank Agreement.  Each Request for Issuance shall be irrevocable unless
modified or rescinded by the Borrower not less than two days prior to the
proposed date of issuance (or effectiveness) specified therein.  Not later
than 12:00 noon on the proposed date of issuance (or effectiveness) specified
in such Request for Issuance, and upon fulfillment of the applicable
conditions precedent and the other requirements set forth herein and in the
relevant LC Bank Agreement, such LC Bank shall issue (or extend, amend or
modify) such Letter of Credit and provide notice and a copy thereof to the
Agent, which shall promptly furnish copies thereof to the Lenders.

     (b)     Each Lender severally agrees with such LC Bank to participate in
the Extension of Credit resulting from the issuance (or extension,
modification or amendment) of such Letter of Credit, in the manner and the
amount provided in Section 3.04(b), and the issuance of such Letter of Credit
shall be deemed to be a confirmation by such LC Bank and each Lender of such
participation in such amount.

     SECTION 3.03.  LC BANK FEES.  The Borrower shall pay directly to each LC
Bank the letter of credit fees, if any, specified to be paid pursuant to the
terms of the LC Bank Agreement to which such LC Bank is a party at the times
and in the manner specified in such LC Bank Agreement.

     SECTION 3.04.  REIMBURSEMENT TO LC BANKS.   (a) The Borrower hereby agrees
to pay to the Agent for the account of each LC Bank, on demand made by such LC
Bank to the Borrower and the Agent, on and after each date on which such LC
Bank shall pay any amount under the Letter of Credit issued by such LC Bank, a
sum equal to the amount so paid plus interest on such amount from the date so
paid by such LC Bank until repayment to such LC Bank in full at a fluctuating
interest rate per annum equal at all times to the interest rate hereunder for
Alternate Base Rate Advances.
<PAGE>
 
                                                                            33

     (b)     If any LC Bank shall not have been reimbursed in full for any
payment made by such LC Bank under the Letter of Credit issued by such LC Bank
on the date of such payment, such LC Bank shall give the Agent and  each
Lender notice thereof (an "LC PAYMENT NOTICE") no later than 12:00 noon on the
Business Day immediately succeeding the date of such payment by such LC Bank.
Each Lender severally agrees to purchase a participation in the reimbursement
obligation of the Borrower to such LC Bank under subsection (a), above, by
paying to the Agent for the account of such LC Bank an amount equal to such
Lender's Percentage of such unreimbursed amount paid by such LC Bank, plus
interest on such amount at a rate per annum equal to the Federal Funds Rate
from the date of such payment by such LC Bank to the date of payment to such
LC Bank by such Lender.  Each such payment by a Lender shall be made not later
than 3:00 P.M. on the later to occur of (i) the Business Day immediately
following the date of such payment by such LC Bank and (ii) the Business Day
on which such Lender shall have received an LC Payment Notice from such LC
Bank.  Each Lender's obligation to make each such payment to the Agent for the
account of such LC Bank shall be several and shall not be affected by the
occurrence or continuance of an Unmatured Default or Event of Default or the
failure of any other Lender to make any payment under this Section 3.04.  Each
Lender further agrees that each such payment shall be made without any offset,
abatement, withholding or reduction whatsoever.

     (c)     The failure of any Lender to make any payment to the Agent for
the account of an LC Bank in accordance with subsection (b), above, shall not
relieve any other Lender of its obligation to make payment, but no Lender
shall be responsible for the failure of any other Lender.  If any Lender shall
fail to make any payment to the Agent for the account of an LC Bank in
accordance with subsection (b), above, within five Business Days after the LC
Payment Notice relating thereto, then, for so long as such failure shall
continue, such LC Bank shall be deemed, for purposes of Section 2.17 and
Article VII hereof, to be a Lender hereunder owed an Advance in an amount
equal to the outstanding principal amount due and payable by such Lender to
the Agent for the account of such LC Bank pursuant to subsection (b), above.

     (d)     Each participation purchased by a Lender under subsection (b),
above, shall constitute an Alternate Base Rate Advance deemed made by such
Lender to the Borrower on the date of such payment by the relevant LC Bank
under the Letter of Credit issued by such LC Bank (irrespective of the
Borrower's noncompliance, if any, with the conditions precedent for Advances
hereunder); and all such payments by the Lenders in respect of any one such
payment by such LC Bank shall constitute a single Borrowing hereunder.
<PAGE>
 
                                                                            34

     SECTION 3.05.  OBLIGATIONS ABSOLUTE.  The payment obligations of each
Lender under Section 3.04(b) and of the Borrower under this Agreement in
respect of any payment under any Letter of Credit and any Advance made under
Section 3.04(d) shall be unconditional and irrevocable, and shall be paid
strictly in accordance with the terms of this Agreement under all
circumstances, including, without limitation, the following circumstances:

             (i)     any lack of validity or enforceability of any Loan
        Document or any other agreement or instrument relating thereto or to
        such Letter of Credit;

             (ii)    any amendment or waiver of, or any consent to departure
        from, all or any of the Loan Documents;

             (iii)   the existence of any claim, set-off, defense or other
        right that the Borrower may have at any time against any beneficiary,
        or any transferee, of such Letter of Credit (or any Persons for whom
        any such beneficiary or any such transferee may be acting), any LC
        Bank, or any other Person, whether in connection with this Agreement,
        the transactions contemplated herein or by such Letter of Credit, or
        any unrelated transaction;

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

             (v)     payment in good faith by any LC Bank under the Letter of
        Credit issued by such LC Bank against presentation of a draft or
        certificate which does not comply with the terms of such Letter of
        Credit; or

             (vi)    any other circumstance or happening whatsoever, whether or
        not similar to any of the foregoing.

     SECTION 3.06.  LIABILITY OF LC BANKS AND THE LENDERS.  The Borrower
assumes all risks of the acts and omissions of any beneficiary or transferee
of any Letter of Credit.  Neither the LC Bank that has issued such Letter of
Credit, the Lenders nor any of their respective officers, directors,
employees, agents or Affiliates shall be liable or responsible for (i) the use
that may be made of such Letter of Credit or any acts or omissions of any
beneficiary or transferee thereof in connection therewith; (ii) the validity,
sufficiency or genuineness of documents, or of any endorsement thereon, even
if such documents should prove to be in any
<PAGE>
 
                                                                            35

or all respects invalid, insufficient, fraudulent or forged; (iii) payment by
such LC Bank against presentation of documents that do not comply with the
terms of such Letter of Credit, including failure of any documents to bear any
reference or adequate reference to such Letter of Credit; or (iv) any other
circumstances whatsoever in making or failing to make payment under such Letter
of Credit, except that the Borrower and each Lender shall have the right to
bring suit against such LC Bank, and such LC Bank shall be liable to the
Borrower and any Lender, to the extent of any direct, as opposed to
consequential, damages suffered by the Borrower or such Lender which the
Borrower or such Lender proves were caused by such LC Bank's wilful misconduct
or gross negligence, including such LC Bank's wilful failure to make timely
payment under such Letter of Credit following the presentation to it by the
beneficiary thereof of a draft and accompanying certificate(s) that strictly
comply with the terms and conditions of such Letter of Credit.  In furtherance
and not in limitation of the foregoing, any LC Bank may accept sight drafts and
accompanying certificates presented under a Letter of Credit issued by such LC
Bank that appear on their face to be in order, without responsibility for
further investigation, regardless of any notice or information to the contrary.
Notwithstanding the foregoing, no Lender (in its capacity as Lender) shall be
obligated to indemnify the Borrower for damages caused by any LC Bank's wilful
misconduct or gross negligence, and the obligation of the Borrower to reimburse
the Lenders hereunder shall be absolute and unconditional, notwithstanding the
gross negligence or wilful misconduct of any LC Bank.


                                   ARTICLE IV
                             CONDITIONS OF LENDING

     SECTION 4.01.  CONDITION PRECEDENT TO INITIAL EXTENSION OF CREDIT.  The
obligation of each Lender to make its initial Extension of Credit is subject
to the satisfaction, prior to or concurrently with the making of such initial
Extension of Credit, of the condition precedent that the Agent shall have
received the following, each dated the same date (unless otherwise specified
below), in form and substance satisfactory to the Agent and each Lender and
(except for the Notes) in sufficient copies for each Lender:

             (i)     The Notes payable to the order of each of the Lenders,
        respectively, duly executed by the Borrower;

             (ii)    A copy of the Guaranty, duly executed by the Parent;
<PAGE>
 
                                                                            36

             (iii)   Certified copies of the resolutions of the Board of
        Directors of the Borrower approving this Agreement, the Notes, the
        other Loan Documents to which it is a party and the transactions
        contemplated hereby and thereby and any other documents to be delivered
        by the Borrower hereunder, and of all documents evidencing other
        necessary corporate action and all Governmental Approvals, if any, with
        respect to this Agreement, the Notes and the other Loan Documents;

             (iv)    Certified copies of the resolutions of the Board of
        Directors of the Parent approving the Guaranty and any other documents
        to be delivered by the Parent hereunder or thereunder, and of all
        documents evidencing other necessary corporate action and all
        Governmental Approvals, if any, with respect to the Guaranty;

             (v)     A certificate of the Secretary or an Assistant Secretary
        of the Borrower certifying (A) the names and true signatures of the
        officers of the Borrower authorized to sign this Agreement, the Notes
        and the other documents to be delivered hereunder and (B) that attached
        thereto are true and correct copies of the Certificate of Incorporation
        (or comparable charter document) and the By-laws of the Borrower, in
        each case as in effect on such date;

             (vi)    A certificate of the Secretary or an Assistant Secretary
        of the Parent certifying (A) the names and true signatures of the
        officers of the Parent authorized to sign the Guaranty and any other
        documents to be delivered by the Parent hereunder or thereunder and (B)
        that attached thereto are true and correct copies of the Certificate of
        Incorporation (or comparable charter document) and By-laws of the
        Parent, in each case as in effect on such date;

             (vii)   A good standing certificate issued by the Secretary of
        State of its incorporation for each of the Borrower and the Parent,
        each dated as of a date not more than five days prior to such date;

             (viii)  A certificate of the chief financial officer of the
        Borrower, or such other officer of the Borrower acceptable to the
        Agent, stating that (A) the representations and warranties contained in
        Section 5.01 of this Agreement are true and correct on and as of the
        date of such certificate as though made on and as of such date and (B)
        no Event of Default and no Unmatured Default has occurred and is
        continuing;
<PAGE>
 
                                                                            37

             (ix)    A certificate of the chief financial officer of the
        Parent, or such other officer of the Parent acceptable to the Agent,
        stating that the representations and warranties contained in Section 6
        of the Guaranty are true and correct on and as of the date of such
        certificate as though made on such date;

             (x)     A favorable opinion of Sidley & Austin, counsel for the
        Borrower and the Parent, substantially in the form of Exhibit F hereto
        and as to such other matters as the Majority Lenders through the Agent
        may reasonably request;

             (xi)    A favorable opinion of King & Spalding, special counsel
        for the Agent, substantially in the form of Exhibit G hereto; and

             (xii)   Such other approvals, opinions and documents as the
        Majority Lenders, through the Agent, may reasonably request.

     SECTION 4.02.  CONDITIONS PRECEDENT TO EACH EXTENSION OF CREDIT.  The
obligation of each Lender or LC Bank, as the case may be, to make an Extension
of Credit (including the initial Extension of Credit) shall be subject to the
further conditions precedent that, on the date of such Extension of Credit and
after giving effect thereto:

     (a)     The following statements shall be true (and each of the giving of
the applicable notice or request with respect thereto and the making of such
Extension of Credit shall constitute a representation and warranty by the
Borrower that, on the date of such Extension of Credit, such statements are
true):

             (i)     the representations and warranties contained in Section
        5.01 of this Agreement (other than those contained in subsections (e)
        and (f) thereof) and in Section 6 of the Guaranty (other than those
        contained in subsections (f) and (g) thereof) are true and correct on
        and as of the date of such Extension of Credit, before and after giving
        effect to such Extension of Credit and to the application of the
        proceeds thereof, as though made on and as of such date; and

             (ii)    no Event of Default has occurred and is continuing, or
        would result from such Extension of Credit or the application of the
        proceeds thereof.

     (b)     The Agent shall have received such other approvals, opinions and
documents as the Majority Lenders or any LC Bank, through the Agent, may
<PAGE>
 
                                                                           38

reasonably request as to the legality, validity, binding effect or
enforceability of the Loan Documents or the financial condition, results of
operations, operations, business, properties or prospects of the Borrower or of
the Parent and its Subsidiaries.

     SECTION 4.03.  CONDITIONS PRECEDENT TO CERTAIN EXTENSIONS OF CREDIT.  The
obligation of each Lender or LC Bank, as the case may be, to make an Extension
of Credit (including the initial Extension of Credit) that would (after giving
effect to all Extensions of Credit on such date and the application of
proceeds thereof) increase the principal amount outstanding hereunder, or to
make an Extension of Credit of the type described in clause (ii) or (iii) of
the definition thereof, shall be subject to the further conditions precedent
that, on the date of such Extension of Credit and after giving effect
thereto:

     (a)     the following statements shall be true (and each of the giving of
the applicable notice or request with respect thereto and the making of such
Extension of Credit shall constitute a representation and warranty by the
Borrower that, on the date of such Extension of Credit, such statements are
true):

             (i)     the representations and warranties contained in
        subsections (e) and (f) of Section 5.01 of this Agreement and in
        subsections (f) and (g) of Section 6 of the Guaranty are true and
        correct on and as of the date of such Extension of Credit, before and
        after giving effect to such Extension of Credit and to the application
        of the proceeds thereof, as though made on and as of such date; and

             (ii)    no Unmatured Default has occurred and is continuing, or
        would result from such Extension of Credit or the application of the
        proceeds thereof.

     (b)     The Agent shall have received such other approvals, opinions and
documents as the Majority Lenders or any LC Bank, through the Agent, may
reasonably request.

     SECTION 4.04.  RELIANCE ON CERTIFICATES.  The Lenders, the LC Banks and
the Agent shall be entitled to rely conclusively upon the certificates
delivered from time to time by officers of the Borrower and the Parent as to
the names, incumbency, authority and signatures of the respective persons
named therein until such time as the Agent may receive a replacement
certificate, in form acceptable to the Agent, from an officer of such Person
identified to the Agent as having authority to deliver such certificate,
setting forth the names and true signatures of
<PAGE>
 
                                                                            39

the officers and other representatives of such Person thereafter authorized to
act on behalf of such Person.


                                   ARTICLE V
                         REPRESENTATIONS AND WARRANTIES

     SECTION 5.01.  REPRESENTATIONS AND WARRANTIES OF THE BORROWER.  The
Borrower represents and warrants as follows:

     (a)     The Borrower is a corporation duly organized, validly existing
and in good standing under the laws of the State of Illinois, and is duly
qualified to do business and is in good standing as a foreign corporation in
each jurisdiction in which the nature of the business conducted or the
property owned, operated or leased by it requires such qualification and where
the failure to so qualify might have a Material Adverse Effect, and has full
power and authority to own and hold under lease its property and to conduct
its business substantially as presently conducted by it.

     (b)     The execution, delivery and performance by the Borrower of this
Agreement, the Notes and the other Loan Documents to which it is a party are
within the Borrower's corporate powers, have been duly authorized by all
necessary corporate action and do not, and will not,  (i) contravene the
Borrower's Certificate of Incorporation (or other comparable charter document)
or By-laws, law or any contractual or legal restriction binding on or
affecting the Borrower or its properties, (ii) result in a breach of, or
constitute a default under, any indenture or loan or credit agreement or any
other agreement, lease or instrument to which the Borrower is a party or by
which it or its properties may be bound or affected, or (iii) result in or
require the creation of any Lien upon or with respect to any of its
properties.

     (c)     No Governmental Approval is required for the due execution,
delivery and performance by the Borrower of this Agreement, the Notes or any
other Loan Document to which it is a party.

     (d)     This Agreement has been duly executed and delivered by the
Borrower and is, and the Notes and the other Loan Documents to which the
Borrower is a party when delivered hereunder will be, legal, valid and binding
obligations of the Borrower enforceable against the Borrower in accordance
with their respective terms.
<PAGE>
 
                                                                            40

     (e)     The balance sheets of the Borrower and its Subsidiaries as at
June 30, 1996, and the related statements of income, cash flows and retained
earnings of the Borrower and its Subsidiaries for the six-month period
(January 1, 1996 to June 30, 1996) then ended, copies of each of which have
been furnished to each Lender, fairly present (subject to year-end
adjustments) the financial condition of the Borrower and its Subsidiaries as
at such date and the results of the operations of the Borrower and its
Subsidiaries for the period ended on such date, all in accordance with GAAP
(except for the absence of notes thereto), and since June 30, 1996, there has
been no material adverse change in the financial condition, results of
operations, operations, business, properties or prospects of the Borrower and
its Subsidiaries, taken as a whole (other than operating losses resulting from
start-up operations of Subsidiaries of the Borrower), or in the Borrower's
ability to perform any of its obligations under this Agreement, the Notes and
the other Loan Documents to which it is a party.

     (f)     There is no pending or threatened action or proceeding affecting
the Borrower, the Parent or any of their respective Subsidiaries before any
court, governmental agency or arbitrator that may result in a Material Adverse
Effect, or that relates to this Agreement or the other Loan Documents or any
transaction contemplated hereby or thereby.

     (g)     No proceeds of any Advance will be used to acquire any equity
security of a class which is registered pursuant to Section 12 of the Exchange
Act or in any transaction subject to the requirements of Section 13 or 14 of
the Exchange Act.

     (h)     The Borrower is not engaged in the business of extending credit
for the purpose of buying or carrying margin stock (within the meaning of
Regulation U issued by the Board of Governors of the Federal Reserve System),
and no proceeds of any Advance and no Letter of Credit will be used to buy or
carry any margin stock or to extend credit to others for the purpose of buying
or carrying any margin stock.

     (i)     Neither the Borrower nor any Subsidiary of the Borrower is in
violation of any law or governmental regulation or court decree or order which
may result in a Material Adverse Effect.

     (j)     Each of the Borrower and its Subsidiaries has filed all tax
returns and reports required by law to have been filed by it and has paid all
taxes and governmental charges thereby shown to be owing, except any such taxes
or charges which are being contested in good faith by appropriate proceedings
and for which adequate reserves in accordance with GAAP shall have been set
aside
<PAGE>
 
                                                                            41

on its books.  No tax Liens have been filed with respect to the Borrower or any
of its Subsidiaries and, to the knowledge of the Borrower, no claims with
respect to any such taxes or charges are being asserted which, individually or
in the aggregate, could result in a Material Adverse Effect.

     (k)     During the preceding twelve-consecutive-month period, no steps
have been taken to terminate any Pension Plan, and no contribution failure has
occurred with respect to any Pension Plan sufficient to give rise to a Lien
under Section 302(f) of ERISA.  No condition exists or event or transaction
has occurred with respect to any Pension Plan which could result in the
incurrence by the Borrower of any material liability, fine, or penalty.  The
Borrower has no contingent liability with respect to any post-retirement
benefit under a Welfare Plan, other than liability for continuation coverage
described in Part 6 of Title I of ERISA.

     (l)     All factual information heretofore or contemporaneously furnished
by or on behalf of the Borrower in writing to any Lender or the Agent for
purposes of or in connection with this Agreement, any other Loan Document or
any transaction contemplated hereby is, and all other such factual information
hereafter furnished by or on behalf of the Borrower or Parent to the Agent or
any Lender will be, true and accurate in every material respect on the date as
of which such information is dated or certified, and not incomplete by
omitting to state any material fact necessary to make such information not
misleading.

     (m)     The Borrower is not (A) a "public utility holding company" within
the meaning of the Public Utility Holding Company Act of 1935, as amended, or
(B) an "investment company" or a company "controlled" by an "investment
company" within the meaning of the Investment Company Act of 1940, as amended,
or an "investment advisor" within the meaning of the Investment Advisors Act
of 1940, as amended.


                                   ARTICLE VI
                           COVENANTS OF THE BORROWER

     SECTION 6.01.  AFFIRMATIVE COVENANTS.  So long as any Note or any amount
payable by the Borrower hereunder shall remain unpaid, any Letter of Credit
shall remain outstanding or any Lender shall have any Commitment hereunder,
the Borrower will, unless the Majority Lenders shall otherwise consent in
writing:

     (a)     REPORTING REQUIREMENTS.  Furnish to each Lender:
<PAGE>
 
                                                                            42

             (i)     as soon as available and in any event within 60 days after
        the end of each of the first three quarters of each fiscal year of the
        Borrower, a consolidated balance sheet of the Borrower and its
        Subsidiaries as of the end of such quarter and consolidated statements
        of income, retained earnings and cash flows of the Borrower and its
        Subsidiaries for the period commencing at the end of the previous
        fiscal year and ending with the end of such quarter, all in reasonable
        detail and duly certified (subject to year-end audit adjustments) by
        the chief financial officer or the Treasurer of the Borrower as having
        been prepared in accordance with GAAP consistently applied, except for
        (A) the absence of notes thereto and (B) changes in accounting
        principles required by GAAP;

             (ii)    as soon as available and in any event within 90 days after
        the end of each fiscal year of the Borrower and its Subsidiaries, a
        consolidated balance sheet of the Borrower and its Subsidiaries as at
        the end of such fiscal year and consolidated statements of income,
        retained earnings and cash flows of the Borrower and its Subsidiaries
        for such fiscal year, certified in a manner acceptable to the Agent by
        Arthur Andersen LLP or another nationally-recognized independent public
        accounting firm selected by the Borrower and acceptable to the Agent;

             (iii)   concurrently with the financial statements for each
        quarterly accounting period and for each fiscal year of the Borrower
        furnished pursuant to paragraphs (i) and (ii), above, (A) a certificate
        of the chief financial officer, any vice president responsible for
        financial or accounting matters, or the Treasurer of the Borrower
        stating that (1)  the Borrower has performed and observed all of, and
        the Borrower is not in default in the performance or observance of any
        of, the terms, covenants, agreements and conditions of this Agreement
        or any other Loan Document or, if the Borrower shall be in default,
        specifying all such defaults and the nature thereof, of which the
        signer of such certificate may have knowledge, and (2) the signer has
        obtained no knowledge of any Unmatured Default or Event of Default
        except as specified in such certificate, and (B) an analysis prepared
        and certified by the chief financial officer, any vice president
        responsible for financial or accounting matters, or the Treasurer of
        the Borrower of the covenant contained in Section 6.02(b) containing
        all information necessary for determining compliance by the Borrower
        with such covenant;

             (iv)    as soon as available and in any event within 90 days after
        the end of each fiscal year of the Borrower and concurrently with the
        financial statements furnished pursuant to paragraph (ii), above, a
        written
<PAGE>
 
                                                                            43

        statement of the independent public accountants that certified
        such financial statements stating that, in making the examination
        necessary for their certification of such financial statements, they
        have obtained no knowledge of any Unmatured Default or Event of Default
        by the Borrower in the observance of any of the covenants contained in
        Section 6.02 or, if such accountants shall have obtained knowledge of
        any such Unmatured Default or Event of Default, specifying all such
        Unmatured Defaults and Events of Defaults and the nature thereof, it
        being understood that they shall not be liable directly or indirectly
        for any failure to obtain knowledge of any Unmatured Default or Event
        of Default;

             (v)     as soon as possible and in any event within ten days after
        the commencement of litigation against the Borrower or any of its
        Subsidiaries that may result in a Material Adverse Effect or that
        questions the validity or enforceability of any Loan Document against
        the Borrower or the Parent, notice of such litigation describing in
        reasonable detail the facts and circumstances concerning such
        litigation and the Borrower's, or such Subsidiary's, as the case may
        be, proposed actions in connection therewith;

             (vi)    if the Borrower has any class of securities registered
        under the Exchange Act, then promptly after the sending or filing
        thereof, copies of all reports which the Borrower sends to any of its
        security holders, and copies of all reports and registration statements
        which the Borrower or any of its Subsidiaries files with the Securities
        and Exchange Commission or any national securities exchange;

             (vii)   promptly after the occurrence of the institution of any
        steps by the Borrower or any other Person to terminate any Pension
        Plan, or the failure to make a required contribution to any Pension
        Plan if such failure is sufficient to give rise to a Lien under Section
        302(f) of ERISA, or the taking of any action with respect to a Pension
        Plan which could result in the requirement that the Borrower or any of
        its Subsidiaries furnish a bond or other security to the PBGC or such
        Pension Plan, or the occurrence of any event with respect to any
        Pension Plan which could result in the incurrence by the Borrower or
        any of its Subsidiaries of any material liability, fine, or penalty, or
        any material increase in the contingent liability of the Borrower or
        any of its Subsidiaries with respect to any post-retirement Welfare
        Plan benefit, notice of such event and the action the Borrower proposes
        to take with respect thereto;
<PAGE>
 
                                                                            44

             (viii)  as soon as possible and in any event within ten days after
        the Borrower knows or should have reason to know of the occurrence of
        each Unmatured Default or Event of Default continuing on the date of
        such statement, a statement of the chief financial officer, any vice
        president responsible for financial or accounting matters, or the
        Treasurer of the Borrower setting forth details of such Unmatured
        Default or Event of Default and the action that the Borrower has taken
        and proposes to take with respect thereto; and

             (ix)    such other information respecting the business, assets,
        revenues, financial condition, results of operations, operations,
        business, properties or prospects of the Borrower or any of its
        Subsidiaries as the Agent or any Lender, through the Agent, may from
        time to time reasonably request.

     (b)     PRESERVATION OF CORPORATE EXISTENCE, ETC.  Preserve and maintain,
and cause each of its Subsidiaries to preserve and maintain, its legal
existence in the jurisdiction of its organization and qualify and remain
qualified as a foreign organization in each jurisdiction in which such
qualification is reasonably necessary in view of its business and operations
or the ownership of its properties, and preserve, renew and keep in full force
and effect the rights, privileges and franchises necessary or desirable in the
normal conduct of its business, except to the extent that the Borrower's chief
financial officer certifies to the Lenders that the loss of any such right,
privilege or franchise, both individually and together with all other rights,
privileges and franchises lost since the date hereof, would not have a
Material Adverse Effect.

     (c)     COMPLIANCE WITH LAWS, ETC.  Comply, and cause each of its
Subsidiaries to comply, in all material respects with all Applicable Laws,
such compliance to include compliance with ERISA and Environmental Laws.

     (d)     MAINTENANCE OF INSURANCE, ETC.  Maintain, and cause each of its
Subsidiaries to maintain, such insurance as may be required by law and such
other insurance, to the extent and against such hazards and liabilities, as is
customarily maintained by companies similarly situated.

     (e)     INSPECTION RIGHTS.  At any reasonable time and from time to time
as the Agent or any Lender may reasonably request, permit the Agent, each
Lender or any agents or representatives thereof to examine and make copies of
and abstracts from the records and books of account of, and visit the
properties of, the Borrower and any of its Subsidiaries, and to discuss the
affairs, finances
<PAGE>
 
                                                                            45

and accounts of the Borrower and any of its Subsidiaries with any of their
respective officers or directors.

     (f)     MAINTAINING OF BOOKS.  Maintain, and cause each of its
Subsidiaries to maintain, complete and accurate books of record and account in
which entries shall be made of all financial transactions and the assets and
business of the Borrower and each of its Subsidiaries in accordance with GAAP.

     (g)     MAINTENANCE OF PROPERTIES.  Cause all properties used or useful
in the conduct of the business of the Borrower or any of its Subsidiaries to
be maintained and kept in reasonable condition, repair and working order, and
cause to be made all necessary repairs, renewals, replacements, betterments
and improvements thereof, all as in the judgment of the Borrower may be
necessary so that the business carried on in connection therewith may be
properly and advantageously conducted at all times; provided, however, that
neither the Borrower nor any such Subsidiary shall be prevented from
discontinuing the operation and maintenance of any such properties if the
chief financial officer of the Borrower certifies that such discontinuance is
desirable in the conduct of the Borrower's or such Subsidiary's business and
such discontinuance, individually or with all such other discontinuances since
the date hereof, would not have a Material Adverse Effect.

     (h)     TAXES AND LIABILITIES.  Pay, and cause each of its Subsidiaries
to pay, when due all taxes, assessments, governmental charges and other
liabilities imposed upon it or its property, except to the extent contested in
good faith and by appropriate proceedings and in respect of which adequate
reserves for the payment thereof have been set aside by the Borrower or such
Subsidiary, as the case may be, in accordance with GAAP.

     (i)     USE OF PROCEEDS.  Use the proceeds of each Extension of Credit
hereunder for general corporate purposes, including, without limitation,
intercompany advances to the Parent in an aggregate amount not to exceed
$25,000,000 at any one time outstanding.

     (j)     ERISA.  Maintain, and cause each of its Subsidiaries to maintain,
each of its defined benefit plans in substantial compliance with all
applicable requirements of ERISA and of the Code and with all applicable
rulings and regulations issued under the provisions of ERISA and the Code.

     SECTION 6.02.  NEGATIVE COVENANTS.  So long as any Note or any amount
payable by the Borrower hereunder shall remain unpaid, any Letter of Credit
shall
<PAGE>
 
                                                                            46

remain outstanding or any Lender shall have any Commitment hereunder, the
Borrower will not, unless the Majority Lenders shall otherwise consent in
writing:

     (a)     BORROWER STOCK.  Permit any of its Subsidiaries to purchase,
redeem, retire, or otherwise acquire for value any shares of capital stock of
the Borrower, or any warrants, rights, or options to acquire any such shares,
now or hereafter outstanding.

     (b)     DEBT.  Create, incur, assume or suffer to exist any Debt, other
than (without duplication) (i) Debt hereunder and under the Notes and the
other Loan Documents, (ii) unsecured Contingent Obligations (other than in
respect of Letters of Credit issued pursuant to Article III hereof) in an
aggregate amount at any one time outstanding not to exceed the excess of (A)
$300,000,000 over (B) the amount of Contingent Obligations incurred by the
Parent pursuant to Section 8(c)(iii) of the Guaranty, and (iii) unsecured
intercompany advances from the Parent subordinated in all respects to any and
all Debt hereunder and under the Notes upon the terms set forth in Exhibit H
hereto; provided, however, that, notwithstanding the foregoing, the aggregate
amount of Debt of the Borrower and its Subsidiaries and of the Parent at any
one time outstanding shall not exceed $750,000,000.

     (c)     INVESTMENTS IN OTHER PERSONS.  Make, or permit any of its
Subsidiaries to make, any loan or advance to any Person or purchase or
otherwise acquire any capital stock, obligations or other securities of, make
any capital contribution to, or otherwise invest in, any Person, except that
(i) so long as no Unmatured Default or Event of Default has occurred and is
continuing, (A) the Borrower may make capital contributions and intercompany
advances to any of its Subsidiaries, and (B) the Borrower or any of its
Subsidiaries may make loans or advances to or other investments in any other
Person to the extent that foreclosure upon any such equity investment or the
stock or assets of the Person to which any such loan or advance was made would
not have a Material Adverse Effect and (ii) the Borrower may make intercompany
advances to the Parent in an aggregate amount not to exceed $25,000,000 at any
one time outstanding.

     (d)     DISTRIBUTIONS.  Upon the occurrence and during the continuance of
an Event of Default, declare or pay, directly or indirectly, any dividend,
payment or other distribution of assets, properties, cash, rights, obligations
or securities on account of any share of any class of capital stock of the
Borrower, or purchase, redeem, retire, or otherwise acquire for value any
shares of any class of capital stock of the Borrower or any warrants, rights,
or options to acquire any such shares, now or hereafter outstanding, or make
any distribution of assets to any of its shareholders.
<PAGE>
 
                                                                            47

     (e)     LIENS, ETC.  Create or suffer to exist, or permit any of its
Subsidiaries to create or suffer to exist, any lien, security interest, or
other charge or encumbrance, or any other type of preferential arrangement,
upon or with respect to any of its properties (including, without limitation,
the capital stock of or any other equity interest in any of its Subsidiaries),
whether now owned or hereafter acquired, or assign, or permit any of its
Subsidiaries to assign, any right to receive income, in each case to secure or
provide for the payment of any Debt of any Person (any of the foregoing being
referred to herein as a "LIEN"), other than (i) Liens imposed by law, such as
carriers', warehousemen's and mechanics' Liens and other similar Liens arising
in the ordinary course of business, (ii) Liens on the capital stock of or any
other equity interest in any of the Borrower's Subsidiaries or any such
Subsidiary's assets to secure the payment and performance of Debt obligations
in connection with any project financing for such Subsidiary (provided that
the obligee of such obligations shall have no recourse to the Borrower to
satisfy such obligations, other than pursuant to any such Liens on the
Borrower's equity interests in its Subsidiaries), (iii) Liens created in
connection with the acquisition by Subsidiaries of assets and the continuation
of such Liens in connection with any refinancing of the Debt secured by such
Liens, provided such Liens are limited to the assets so acquired, (iv) Liens on
the assets and/or rights to receive income of any Person that exist at the
time such Person becomes a Subsidiary and the continuation of such Liens in
connection with any refinancing or restructuring of the obligations secured by
such Liens, (v) Liens created in connection with the incurrence by
Subsidiaries from time to time of an amount not to exceed $375,000,000 of Debt
at any one time outstanding and the continuation of such Liens in connection
with any refinancing of such Debt and (vi) Liens on the capital stock or other
equity interest evidencing an investment permitted under Section
6.02(c)(i)(B), provided such Liens are created in connection with the
financing of the business of such Person.

     (f)     MERGERS; SALE OF ASSETS; ETC.  (i) Merge or consolidate with or
into any Person, or (ii) convey, transfer, lease or otherwise dispose of, or
permit any of its Subsidiaries to convey, transfer, lease or otherwise dispose
of, whether in one transaction or in a series of transactions, and whether in
a sale/leaseback transaction or otherwise, any assets of the Borrower and its
Subsidiaries (measured on a consolidated basis) (whether now owned or
hereafter acquired), unless (A) in the case of a merger involving the Borrower,
immediately after giving effect thereto, (1) no event shall occur and be
continuing that constitutes an Unmatured Default or an Event of Default, (2)
the Borrower is the surviving corporation, and (3) the Borrower and its
Subsidiaries shall not be liable with respect to any Debt or allow their
respective properties to be subject to any Lien which the Borrower or any such
Subsidiary could not become liable with respect to or allow its property to
become subject to under this Agreement on the date of such
<PAGE>
 
                                                                            48

transaction, or (B) in the case of any disposition of assets or any
sale/leaseback transaction, immediately after giving effect thereto, no event
shall have occurred and be continuing that constitutes an Unmatured Default or
an Event of Default (including, without limitation, any Unmatured Default or
Event of Default that would result from a breach by the Parent of Section 7(i)
of the Guaranty).

     (g)     OTHER AGREEMENTS.  Enter into, or permit any of its Subsidiaries
to enter into, any agreement containing any provision that would be violated
or breached by the performance of its obligations hereunder or under any
instrument or document delivered or to be delivered by the Borrower hereunder
or in connection herewith.

     (h)     REGULATION U.  Use or permit any Letter of Credit or any proceeds
of any Advance to be used, whether directly or indirectly, for the purpose,
whether immediate, incidental, or ultimate, of "buying or carrying any margin
stock" within the meaning of Regulation U of the Board of Governors of the
Federal Reserve System.

     (i)     TRANSACTIONS WITH AFFILIATES.  Enter into, or permit any of its
Subsidiaries to enter into, any transaction with an Affiliate of the Borrower,
unless such transaction is on terms no less favorable to the Borrower or such
Subsidiary, as the case may be, than if the transaction had been negotiated in
good faith on an arm's length basis with a Person that was not an Affiliate of
the Borrower; provided, however, that the foregoing restrictions shall not
apply to any transaction between the Borrower and any of its Subsidiaries or
between Commonwealth and the Borrower or any of the Borrower's Subsidiaries.


                                  ARTICLE VII
                               EVENTS OF DEFAULT

     SECTION 7.01.  EVENTS OF DEFAULT.  If any of the following events (each an
"EVENT OF DEFAULT") shall occur and be continuing after the applicable grace
period and notice requirement (if any), the Agent and the Lenders shall be
entitled to exercise the remedies set forth in Section 7.02:

     (a)     the Borrower shall fail to pay any principal of any Note, or any
reimbursement obligation in respect of any drawing under any Letter of Credit,
when the same becomes due and payable; or
<PAGE>
 
                                                                            49

     (b)     the Borrower shall fail to pay any interest on any Note, any fees
or any other amount due under this Agreement for two Business Days after the
same becomes due and payable; or

     (c)     any representation or warranty made or deemed made by the
Borrower herein or in any of the other Loan Documents or by the Borrower (or
any of its officers) in connection with this Agreement or any of the Loan
Documents, or any representation or warranty made or deemed made by the Parent
in the Guaranty or by the Parent (or any of its officers) in connection with
the Guaranty, shall prove to have been incorrect in any material respect when
made or deemed made; or

     (d)      (i) the Borrower shall fail to perform or observe any term,
covenant, or agreement contained in Section 6.01(i) or Section 6.02; (i) the
Parent shall fail to perform or observe any term, covenant or agreement
contained in Section 7(i), Section 7(j), Section 7(l) or Section 8 of the
Guaranty; (ii) the Borrower shall fail to perform or observe any other term,
covenant, or agreement contained in this Agreement or in any other Loan
Document on its part to be performed or observed (and not constituting an
Event of Default under any of the other provisions of this Section 7.01) if
such failure shall remain unremedied for 30 days; or (iii) the Parent shall fail
to perform or observe any other term, covenant, or agreement contained in the
Guaranty on its part to be performed or observed (and not constituting an
Event of Default under any of the other provisions of this Section 7.01) if
such failure shall remain unremedied for 30 days; or

     (e)     Commonwealth shall fail to pay any principal of or premium or
interest on any of its Debt which is outstanding in a principal amount of at
least $25,000,000 in the aggregate, when the same becomes due and payable
(whether by scheduled maturity, required prepayment, acceleration, demand, or
otherwise), and such failure shall continue after the applicable grace period,
if any, specified in the agreement or instrument relating to such Debt; or any
other event shall occur or condition shall exist under any agreement or
instrument relating to any such Debt and shall continue after the applicable
grace period, if any, specified in such agreement or instrument, if the effect
of such event or condition is to accelerate, or to permit the acceleration of,
the maturity of such Debt; or any such Debt shall be declared to be due and
payable, or required to be prepaid (other than by a regularly scheduled
required prepayment), prior to the stated maturity thereof; or

     (f)     the Parent shall fail to pay any principal of or premium or
interest on any of its Debt which is outstanding in a principal amount of at
least
<PAGE>
 
                                                                            50

$5,000,000 in the aggregate, when the same becomes due and payable (whether by
scheduled maturity, required prepayment, acceleration, demand, or otherwise),
and such failure shall continue after the applicable grace period, if any,
specified in the agreement or instrument relating to such Debt; or any other
event shall occur or condition shall exist under any agreement or instrument
relating to any such Debt and shall continue after the applicable grace period,
if any, specified in such agreement or instrument, if the effect of such event
or condition is to accelerate, or to permit the acceleration of, the maturity
of such Debt; or any such Debt shall be declared to be due and payable, or
required to be prepaid (other than by a regularly scheduled required
prepayment), prior to the stated maturity thereof; or

     (g)     the Borrower or any of its Subsidiaries shall fail to pay any
principal of or premium or interest on any of its Debt (excluding Debt
evidenced by the Notes and any Debt secured by a Lien of the type referred to
in Section 6.02(e)(ii)) which is outstanding in a principal amount of at least
$5,000,000 in the aggregate, when the same becomes due and payable (whether by
scheduled maturity, required prepayment, acceleration, demand, or otherwise),
and such failure shall continue after the applicable grace period, if any,
specified in the agreement or instrument relating to such Debt; or any other
event shall occur or condition shall exist under any agreement or instrument
relating to any such Debt and shall continue after the applicable grace
period, if any, specified in such agreement or instrument, if the effect of
such event or condition is to accelerate, or to permit the acceleration of,
the maturity of such Debt; or any such Debt shall be declared to be due and
payable, or required to be prepaid (other than by a regularly scheduled
required prepayment), prior to the stated maturity thereof; or

     (h)     either (i) the Parent, Commonwealth, the Borrower or any
Significant Subsidiary shall generally fail to pay, or admit in writing its
inability to pay, its debts as they become due, or shall voluntarily commence
any proceeding or file any petition under any bankruptcy, insolvency, or
similar law seeking dissolution, liquidation, or reorganization or the
appointment of a receiver, trustee, custodian, or liquidator for itself or a
substantial portion of its property, assets, or business, or to effect a plan
or other arrangement with its creditors, or shall file any answer admitting
the jurisdiction of the court and the material allegations of any involuntary
petition filed against it in any bankruptcy, insolvency, or similar
proceeding, or shall be adjudicated bankrupt, or shall make a general
assignment for the benefit of creditors, or shall consent to, or acquiesce in
the appointment of, a receiver, trustee, custodian, or liquidator for itself
or a substantial portion of its property, assets, or business, or (ii)
corporate action shall be taken by the Parent, Commonwealth, the Borrower or
any Significant Subsidiary for the purpose of effectuating any of the
foregoing; or
<PAGE>
 
                                                                            51

     (i)     involuntary proceedings or an involuntary petition shall be
commenced or filed against the Parent, Commonwealth, the Borrower or any
Significant Subsidiary under any bankruptcy, insolvency, or similar law or
seeking the dissolution, liquidation, or reorganization of the Parent,
Commonwealth, the Borrower or such Significant Subsidiary (as the case may be)
or the appointment of a receiver, trustee, custodian, or liquidator for the
Parent, Commonwealth, the Borrower or such Significant Subsidiary (as the case
may be) or of a substantial part of the property, assets, or business of the
Parent, Commonwealth, the Borrower or such Significant Subsidiary (as the case
may be), or any writ, judgment, warrant of attachment, execution, or similar
process shall be issued or levied against a substantial part of the property,
assets, or business of the Parent, Commonwealth, the Borrower or any
Significant Subsidiary, and such proceedings or petition shall not be
dismissed, or such writ, judgment, warrant of attachment, execution, or
similar process shall not be released, vacated, or fully bonded, within 45
days after commencement, filing, or levy, as the case may be; or

     (j)     any judgment or order for the payment of money in excess of (i)
$5,000,000 shall be rendered against the Parent or the Borrower or any
Subsidiary of the Borrower or any of their respective properties, or (ii)
$20,000,000 shall be rendered against Commonwealth or any of its properties,
and either (A) enforcement proceedings shall have been commenced by any
creditor upon such judgment or order, or (B) there shall be any period during
which a stay of enforcement of such judgment or order, by reason of a pending
appeal or otherwise, shall not be in effect; or

     (k)      (i) the institution of any steps by the Borrower or any sponsor
of a Pension Plan to terminate a Pension Plan, if as a result of such
termination the Borrower or any of its Subsidiaries could be required to make
a contribution to such Pension Plan, or could incur a liability or obligation
to such Pension Plan, in excess of $5,000,000, or (ii) a contribution failure
occurs with respect to any Pension Plan sufficient to give rise to a Lien
under Section 302(f) of ERISA; or

     (l)     the Borrower or any of its Subsidiaries shall default in the
payment when due, or in the performance or observance of, any Debt described
in clause (iii), (vii), or (viii) of the definition of "Debt" or any material
obligation of, or material condition agreed to by, the Borrower or such
Subsidiary with respect to any material purchase or lease of goods or services
(subject to any applicable grace period and except as waived or to the extent
that the existence of any such default is being contested in good faith by
appropriate proceedings and reserves therefor are being maintained in
accordance with GAAP); or
<PAGE>
 
                                                                            52

     (m)     the Parent shall fail to own directly 100% of the issued and
outstanding shares of capital stock of the Borrower or 80% of the issued and
outstanding shares of voting capital stock of Commonwealth; or

     (n)     any provision of the Guaranty or any of the subordination
provisions of any Debt incurred by the Borrower pursuant to Section
6.02(b)(iii) shall for any reason (except pursuant to the terms thereof) cease
to be valid and binding on the Parent or the Parent shall so assert in
writing; or

     (o)     any provision of any Loan Document to which the Borrower is a
party shall for any reason (except pursuant to the terms thereof) cease to be
valid and binding on the Borrower or the Borrower shall so assert in writing;
or

     (p)     at any time any LC Bank shall have been served with or otherwise
subjected to a court order, injunction, or other process or decree issued or
granted at the instance of the Borrower restraining or seeking to restrain
such LC Bank from paying any amount under any Letter of Credit issued by it
and either (i) there has been a drawing under such Letter of Credit which such
LC Bank would otherwise be obligated to pay or (ii) the stated expiration date
or any reduction of the stated amount of such Letter of Credit has occurred
but the right of the beneficiary to draw thereunder has been extended in
connection with the pendency of the related court action or proceeding; or

     (q)     the Parent shall receive cash dividends from its Subsidiaries in
any two consecutive fiscal quarters of the Parent in an aggregate amount less
than $150,000,000.

     SECTION 7.02.  REMEDIES.  If any Event of Default has occurred and is
continuing, then the Agent shall at the request, or may with the consent, of
the Majority Lenders, upon notice to the Borrower (i) declare the Commitments
and the obligation of each Lender to make Advances (other than Advances under
Section 3.04 hereof) and of any LC Bank to issue a Letter of Credit to be
terminated, whereupon the same shall forthwith terminate, (ii) declare the
Notes, all interest thereon and all other amounts payable under this Agreement
and the other Loan Documents to be forthwith due and payable, whereupon the
Notes, all such interest and all such amounts shall become and be forthwith
due and payable, without presentment, demand, protest or further notice of any
kind, all of which are hereby expressly waived by the Borrower, and (iii) make
demand upon the Borrower to, and forthwith upon such demand the Borrower
shall, deposit with the Agent in same day funds in a special interest-bearing
cash escrow account maintained by the Agent at the Agent's office and pledged
to the Agent for the benefit of the Lenders pursuant to documentation
satisfactory to the Agent, an
<PAGE>
 
                                                                            53

amount equal to the aggregate LC Outstandings, such cash escrow to be held for
the benefit of the LC Banks and the Lenders as security for the payment
obligations of the Borrower under this Agreement, the Notes and the other Loan
Documents; provided, however, that in the event of an actual or deemed entry of
an order for relief with respect to the Borrower under the Bankruptcy Code, (A)
the Commitments and the obligation of each Lender to make Advances and of any
LC Bank to issue any Letter of Credit shall automatically be terminated and (B)
the Notes, all such interest and all such amounts shall automatically become
and be due and payable, without presentment, demand, protest or any notice of
any kind, all of which are hereby expressly waived by the Borrower.
Notwithstanding anything to the contrary contained herein, no notice given or
declaration made by the Agent pursuant to this Section 7.02 shall affect (i)
the obligation of any LC Bank to make any payment under any Letter of Credit
issued by such LC Bank in accordance with the terms of such Letter of Credit or
(ii) the participatory interest of each Lender in each such payment thereunder.


                                  ARTICLE VIII
                                   THE AGENT

     SECTION 8.01.  AUTHORIZATION AND ACTION.  Each Lender and LC Bank hereby
appoints and authorizes the Agent to take such action as agent on its behalf
and to exercise such powers under this Agreement and the other Loan Documents
as are delegated to the Agent by the terms hereof and thereof, together with
such powers as are reasonably incidental thereto.  As to any matters not
expressly provided for by this Agreement or any other Loan Document
(including, without limitation, enforcement or collection of the Notes), the
Agent shall not be required to exercise any discretion or take any action, but
shall be required to act or to refrain from acting (and shall be fully
protected in so acting or refraining from acting) upon the instructions of the
Majority Lenders, and such instructions shall be binding upon all Lenders and
all holders of Notes; provided, however, 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 applicable law.  The Agent agrees to give to
each Lender prompt notice of each notice given to it by the Borrower pursuant
to the terms of this Agreement.

     SECTION 8.02.  AGENT'S RELIANCE, ETC.  Neither the Agent nor any of its
directors, officers, agents, or employees shall be liable to any Lender, any
LC Bank or the Borrower for any action taken or omitted to be taken by it or
them under or in connection with this Agreement or any other Loan Document,
except for its or their own gross negligence or wilful misconduct. Without
limitation of the generality of the foregoing, the Agent:   (a) may treat the
payee of any Note
<PAGE>
 
                                                                            54

as the holder thereof until the Agent receives and accepts a Lender Assignment
entered into by the Lender which is the payee of such Note, as assignor, and an
Eligible Assignee, as assignee, as provided in Section 9.07; (b) may consult
with legal counsel (including counsel for the Borrower), independent public
accountants and other experts selected by it and shall not be liable for any
action taken or omitted to be taken in good faith by it in accordance with the
advice of such counsel, accountants or experts; (c) makes no warranty or
representation to any Lender or LC Bank and shall not be responsible to any
Lender or LC Bank for any statements, warranties, or representations (whether
written or oral) made in or in connection with this Agreement or any other Loan
Document; (d) shall not have any duty to ascertain or to inquire as to the
performance or observance of any of the terms, covenants or conditions of this
Agreement or any other Loan Document on the part of the Borrower or the Parent
or to inspect the property (including the books and records) of the Borrower or
the Parent; (e) shall not be responsible to any Lender or LC Bank for the due
execution, legality, validity, enforceability, genuineness, sufficiency, or
value of this Agreement, any other Loan Document, or any other instrument or
document furnished pursuant hereto or thereto; and (f) shall incur no liability
under or in respect of this Agreement or any other Loan Document by acting upon
any notice, consent, certificate, or other instrument or writing (which may be
by telecopier, telegram, cable, or telex) believed by it to be genuine and
signed or sent by the proper party or parties.

     SECTION 8.03.  CITIBANK AND AFFILIATES.  With respect to its Commitment,
the Advances made by it and the Notes issued to it, Citibank shall have the
same rights and powers under this Agreement as any other Lender and may
exercise the same as though it were not the Agent; and the term "Bank" or
"Banks" and "Lender" or "Lenders" shall, unless otherwise expressly indicated,
include Citibank in its individual capacity.  Citibank and its Affiliates may
accept deposits from, lend money to, act as trustee under indentures of, and
generally engage in any kind of business with, the Borrower, any of its
Subsidiaries and any Person who may do business with or own securities of the
Borrower or any such Subsidiary, all as if Citibank were not the Agent and
without any duty to account therefor to the Lenders.

     SECTION 8.04.  LENDER CREDIT DECISION.  Each Lender acknowledges that it
has, independently and without reliance upon the Agent or any other Lender and
based on the financial statements referred to in Section 5.01(e) and such other
documents and information as it has deemed appropriate, made its own credit
analysis and decision to enter into this Agreement.  Each Lender also
acknowledges that it will, independently and without reliance upon the Agent or
any other Lender and based on such documents and information as it shall deem
<PAGE>
 
                                                                            55

appropriate at the time, continue to make its own credit decisions in taking or
not taking action under this Agreement.

     SECTION  8.05.  INDEMNIFICATION.  The Lenders agree to indemnify the Agent
(to the extent not reimbursed by the Borrower), ratably according to the
respective principal amounts of the Notes then held by each of them (or if no
Notes are at the time outstanding or if any Notes are held by Persons which
are not Lenders, ratably according to the respective Percentages of the
Lenders), from and against any and all liabilities, obligations, losses,
damages, penalties, actions, judgments, suits, costs, expenses, or
disbursements of any kind or nature whatsoever which may be imposed on,
incurred by, or asserted against the Agent in any way relating to or arising
out of this Agreement or any action taken or omitted by the Agent under this
Agreement, provided that no Lender shall be liable for any portion of such
liabilities, obligations, losses, damages, penalties, actions, judgments,
suits, costs, expenses, or disbursements resulting from the Agent's gross
negligence or wilful misconduct.  Without limitation of the foregoing, each
Lender agrees to reimburse the Agent promptly upon demand for its ratable
share of any out-of-pocket expenses (including counsel fees) incurred by the
Agent in connection with the preparation, execution, delivery, administration,
modification, amendment, or enforcement (whether through negotiations, legal
proceedings or otherwise) of, or legal advice in respect of rights or
responsibilities under, this Agreement, to the extent that the Agent is not
reimbursed for such expenses by the Borrower.

     SECTION 8.06.  SUCCESSOR AGENT.  The Agent may resign at any time by giving
written notice thereof to the Lenders and the Borrower and may be removed at
any time with or without cause by the Majority Lenders, with any such
resignation or removal to become effective only upon the appointment of a
successor Agent pursuant to this Section 8.06.  Upon any such resignation or
removal, the Majority Lenders shall have the right to appoint a successor
Agent, which shall be another commercial bank or trust company reasonably
acceptable to the Borrower organized under the laws of the United States or of
any State thereof.  If no successor Agent shall have been so appointed by the
Majority Lenders, and shall have accepted such appointment, within 30 days
after the retiring Agent's giving of notice of resignation or the Majority
Lenders' removal of the retiring Agent, then the retiring Agent may, on behalf
of the Lenders, appoint a successor Agent, which shall be another commercial
bank or trust company organized under the laws of the United States of any
State thereof reasonably acceptable to the Borrower.  Upon the acceptance of
any appointment as Agent hereunder by a successor Agent, such successor Agent
shall thereupon succeed to and become vested with all the rights, powers,
privileges and duties of the retiring Agent, and the retiring Agent shall be
discharged from its duties and
<PAGE>
 
                                                                            56

obligations under this Agreement.  After any retiring Agent's resignation or
removal hereunder as Agent, the provisions of this Article VIII shall inure to
its benefit as to any actions taken or omitted to be taken by it while it was
Agent under this Agreement. Notwithstanding the foregoing, the Borrower shall
not have any approval rights with respect to any successor Agent if, at the
time of appointment of such successor Agent, an Unmatured Default or an Event
of Default shall have occurred and be continuing.


                                   ARTICLE IX
                                 MISCELLANEOUS

     SECTION 9.01.  AMENDMENTS, ETC.  No amendment or waiver of any provision
of any Loan Document, nor consent to any departure by the Borrower therefrom,
shall in any event be effective unless the same shall be in writing and signed
by the Majority Lenders and, in the case of any amendment, the Borrower, and
then such waiver or consent shall be effective only in the specific instance
and for the specific purpose for which given; provided, however, that no
amendment, waiver or consent shall, unless in writing and signed by all the
Lenders, do any of the following:  (a) waive, modify or eliminate any of the
conditions specified in Article IV, (b) increase the Commitments of any of the
Lenders or subject any of the Lenders to any additional obligations, (c)
except as otherwise provided in Section 2.18, extend the term of the
Commitments of any of the Lenders, (d) reduce the principal of, or interest
on, the Notes, any Applicable Margin or any fees or other amounts payable
hereunder, (e) postpone any date fixed for any payment of principal of, or
interest on, the Notes or any fees or other amounts payable hereunder, (f)
change the Percentage of the Commitments or of the aggregate unpaid principal
amount of the Notes, or the number of Lenders, which shall be required for the
Lenders or any of them to take any action hereunder, (g) amend any Loan
Document in a manner intended to prefer one or more Lenders, (h) release the
Parent from its guaranty obligations under the Guaranty or (i) amend this
Section 9.01; and provided, further, that no amendment, waiver or consent
shall, unless in writing and signed by the Agent in addition to the Lenders
required above to take such action, affect the rights or duties of the Agent
under this Agreement or any other Loan Document.

     SECTION 9.02.  NOTICES, ETC.  All notices and other communications provided
for hereunder and under the other Loan Documents shall be in writing (including
telecopier, telegraphic, telex or cable communication) and mailed, telecopied,
telegraphed, telexed, cabled, or delivered, if to the Borrower, at its address
at P.O. Box A-3005, 10 South Dearborn Street, 38th Floor, Chicago, Illinois
60690-3005, Attention: Treasurer (Telephone:  312-394-3153 or 312-394-
<PAGE>
 
                                                                            57

8203; and Telecopier:  312-394-4082); if to any Bank, at its Domestic Lending
Office specified opposite its name on Schedule I hereto; if to any other
Lender, at its Domestic Lending Office specified in the Lender Assignment
pursuant to which it became a Lender; and if to the Agent, at its address at
One Court Square, 7th Floor, Zone 1, Long Island City, New York 11120,
Attention:  Bank Loan Syndications (Telephone: 718-248-4505; Telecopier:
718-248-4844); or, as to each party, at such other address as shall be
designated by such party in a written notice to the other parties. All such
notices and communications shall, when mailed, telecopied, telegraphed, telexed
or cabled, be effective five days after being deposited in the mails, or when
delivered to the telegraph company, telecopied, confirmed by telex answerback
or delivered to the cable company, respectively, except that notices and
communications to the Agent pursuant to Article II or VIII shall not be
effective until received by the Agent.

     SECTION 9.03.  NO WAIVER; REMEDIES.  No failure on the part of any Lender,
any LC Bank or the Agent to exercise, and no delay in exercising, any right
hereunder or under any other Loan Document shall operate as a waiver thereof;
nor shall any single or partial exercise of any such right preclude any other
or further exercise thereof or the exercise of any other right.  The remedies
herein provided are cumulative and not exclusive of any remedies provided by
law.

     SECTION 9.04.  COSTS, EXPENSES, TAXES AND INDEMNIFICATION.   (a) The
Borrower agrees to pay on demand all costs and expenses of the Agent in
connection with the preparation (including, without limitation, printing
costs), negotiation, execution, delivery, administration, modification and
amendment of this Agreement and the other Loan Documents, and the other
documents and instruments to be delivered hereunder and thereunder, including,
without limitation, the reasonable fees and out-of-pocket expenses of counsel
for the Agent with respect thereto and with respect to advising the Agent as to
its rights and responsibilities under this Agreement and the other Loan
Documents.  The Borrower further agrees to pay on demand all costs and
expenses, if any (including, without limitation, reasonable counsel fees and
expenses of outside counsel and internal counsel), of the Agent, the Lenders
and the LC Banks in connection with the enforcement (whether through
negotiations, legal proceedings, or otherwise) of this Agreement and the other
Loan Documents and the other documents and instruments to be delivered
hereunder
<PAGE>
 
                                                                            58

and thereunder, including, without limitation, reasonable counsel fees and
expenses in connection with the enforcement of rights under this Section
9.04(a).  In addition, the Borrower shall pay any and all stamp and other taxes
payable or determined to be payable in connection with the execution and
delivery of this Agreement and the other Loan Documents, and the other
documents and instruments to be delivered hereunder and thereunder, and agrees
to save the Agent and each Lender harmless from and against any and all
liabilities with respect to or resulting from any delay in paying or omission
to pay such taxes.

     (b)     If any payment of principal of, or Conversion of any Eurodollar
Rate Advance is made other than on the last day of the Interest Period for
such Advance or as a result of a payment or Conversion pursuant to Section
2.09(f), 2.10, 2.11, 2.12 or 2.14 or acceleration of the maturity of the Notes
pursuant to Section 7.02 or for any other reason, the Borrower shall, upon
demand by any Lender (with a copy of such demand to the Agent), pay to the
Agent for the account of such Lender any amounts required to compensate such
Lender for any additional losses, costs, or expenses which it may reasonably
incur as a result of such payment or Conversion, including, without
limitation, any loss, cost, or expense incurred by reason of the liquidation
or reemployment of deposits or other funds acquired by any Lender to fund or
maintain such Advance.

     (c)     The Borrower hereby agrees to indemnify and hold harmless each
Lender, each LC Bank, the Agent, counsel to the Agent and their respective
officers, directors, partners, employees and Affiliates (each, an "INDEMNIFIED
PERSON") from and against any and all claims, damages, losses, liabilities,
costs, or expenses (including reasonable attorney's fees and expenses, whether
or not such Indemnified Person is named as a party to any proceeding or is
otherwise subjected to judicial or legal process arising from any such
proceeding) which any of them may incur or which may be claimed against any of
them by any Person:

                  (i)     by reason of or in connection with the execution,
        delivery, or performance of any of the Loan Documents or any
        transaction contemplated thereby, or the use by the Borrower of the
        proceeds of any Extension of Credit; and

                  (ii)    in connection with or resulting from the utilization,
        storage, disposal, treatment, generation, transportation, release, or
        ownership of any Hazardous Substance (i) at, upon, or under any
        property of the Borrower or any of its Affiliates or (ii) by or on
        behalf of the Borrower or any of its Affiliates at any time and in any
        place.

     (d)     The Borrower's obligations under this Section 9.04 shall survive
the repayment of all amounts owing to the Lenders, the LC Banks and the Agent
under the Loan Documents and the termination of the Commitments.  If and to
the extent that the obligations of the Borrower under this Section 9.04 are
unenforceable for any reason, the Borrower agrees to make the maximum
<PAGE>
 
                                                                            59

contribution to the payment and satisfaction thereof which is permissible under
applicable law.

     SECTION 9.05.  RIGHT OF SET-OFF.   (a) Upon  (i) the occurrence and during
the continuance of any Event of Default and (ii) the making of the request or
the granting of the consent specified by Section 7.02 to authorize the Agent
to declare the Notes due and payable pursuant to the provisions of Section
7.02, each Lender and LC Bank is hereby authorized at any time and from time
to time, to the fullest extent permitted by law, to set off and apply any and
all deposits (general or special, time or demand, provisional, or final) at
any time held and other indebtedness at any time owing by such Lender or LC
Bank to or for the credit or the account of the Borrower against any and all
of the obligations of the Borrower now or hereafter existing under any Loan
Document and any Note held by such Lender, irrespective of whether or not such
Lender or LC Bank shall have made any demand under such Loan Document or such
Note and although such obligations may be unmatured.  Each Lender and LC Bank
agrees promptly to notify the Borrower after any such set-off and application
made by such Lender or LC Bank, provided that the failure to give such notice
shall not affect the validity of such set-off and application.  The rights of
each Lender and LC Bank under this Section 9.05 are in addition to other
rights and remedies (including, without limitation, other rights of set-off)
which such Lender or LC Bank may have.

     (b)     The Borrower agrees that it shall have no right of set-off,
deduction, or counterclaim in respect of its obligations hereunder, and that
the obligations of the Lenders hereunder are several and not joint.  Nothing
contained herein shall constitute a relinquishment or waiver of the Borrower's
rights to any independent claim that the Borrower may have against the Agent,
any Lender or any LC Bank for the Agent's, such Lender's or such LC Bank's, as
the case may be, gross negligence or wilful misconduct, but no Lender or LC
Bank shall be liable for the conduct of the Agent, any other Lender or any
other LC Bank, and the Agent shall not be liable for the conduct of any Lender
or LC Bank.

     SECTION 9.06.  BINDING EFFECT.  This Agreement shall become effective when
it shall have been executed by the Borrower and the Agent and when the Agent
shall have been notified in writing by each Bank that such Bank has executed
it and thereafter shall be binding upon and inure to the benefit of the
Borrower, the Agent, each LC Bank and each Lender and their respective
successors and assigns, except that the Borrower shall not have the right to
assign its rights or obligations hereunder or any interest herein without the
prior written consent of the Lenders.
<PAGE>
 
                                                                            60

     SECTION 9.07.  ASSIGNMENTS AND PARTICIPATIONS.   (a) Each Lender may, with
the consent of the Borrower (such consent not to be unreasonably withheld or
delayed), assign to one or more banks or other entities all or a portion of
its rights and obligations under this Agreement and the other Loan Documents
(including, without limitation, all or a portion of its Commitment, the
Advances owing to it and the Note or Notes held by it); provided, however,
that  (i) each such assignment shall be of a constant, and not a varying,
percentage of all of the assigning Lender's rights and obligations under this
Agreement, (ii) after giving effect to any partial assignment, the amount of
the Commitment of each of the assigning and the assignee Lender shall in no
event be less than $10,000,000, (iii) each such assignment shall be to an
Eligible Assignee, and (iv) the parties to each such assignment shall execute
and deliver to the Agent a duly completed Lender Assignment, together with any
Note or Notes subject to such assignment and a processing and recordation fee
of $2,500; and provided, further, however, that the consent of the Borrower
shall not be required for any assignments (A) by a Lender to any of its
Affiliates or (B) made during the continuance of an Event of Default.
Promptly following its receipt of such Lender Assignment, Note or Notes and
fee, the Agent shall accept and record such Lender Assignment in the
Register.  Upon such execution, delivery, acceptance and recording, from and
after the effective date specified in each Lender Assignment, which effective
date shall be at least five Business Days after the execution thereof, (x) the
assignee thereunder shall be a party hereto and, to the extent that rights and
obligations hereunder have been assigned to it pursuant to such Lender
Assignment, have the rights and obligations of a Lender hereunder and (y) the
Lender assignor thereunder shall, to the extent that rights and obligations
hereunder have been assigned by it to an Eligible Assignee pursuant to such
Lender Assignment, relinquish its rights and be released from its obligations
under this Agreement (and, in the case of a Lender Assignment covering all or
the remaining portion of an assigning Lender's rights and obligations under
this Agreement, such Lender shall cease to be a party hereto); provided,
however, that the limitation set forth in clause (ii), above, shall not apply
if an Event of Default shall have occurred and be continuing and the Agent
shall have declared all Advances to be immediately due and payable hereunder.
In addition to, and notwithstanding, the foregoing, any Lender may at any time
pledge or assign for security purposes its rights to receive payments
hereunder (or any part thereof) to any Federal Reserve Bank; provided,
however, that no such pledge or assignment shall relieve the pledging or
assigning Lender from its obligations hereunder or grant to such Federal
Reserve Bank any right to direct such Lender with respect to any action which
such Lender would be entitled to take or omit to take hereunder but for the
existence of such pledge or assignment.
<PAGE>
 
                                                                            61

     (b)     By executing and delivering a Lender Assignment, the Lender
assignor thereunder and the assignee thereunder confirm to and agree with each
other and the other parties hereto as follows:   (i) other than as provided in
such Lender Assignment, such assigning Lender makes no representation or
warranty and assumes no responsibility with respect to any statements,
warranties or representations made in or in connection with any Loan Document
or any other instrument or document furnished pursuant thereto or the
execution, legality, validity, enforceability, genuineness, sufficiency, or
value of any Loan Document or any other instrument or document furnished
pursuant thereto; (ii) such assigning Lender makes no representation or
warranty and assumes no responsibility with respect to the financial condition
of the Borrower or the Parent or the performance or observance by the Borrower
or the Parent of any of their obligations under any Loan Document or any other
instrument or document furnished pursuant thereto; (iii) such assignee confirms
that it has received a copy of each Loan Document, together with such other
documents and information as it has deemed appropriate to make its own credit
analysis and decision to enter into such Lender Assignment; (iv) such assignee
will, independently and without reliance upon the Agent, such assigning Lender
or any other Lender and based on such documents and information as it shall
deem appropriate at the time, continue to make its own credit decisions in
taking or not taking action under the Loan Documents; (v) such assignee
confirms that it is an Eligible Assignee; (vi) such assignee appoints and
authorizes the Agent to take such action as agent on its behalf and to
exercise such powers under the Loan Documents as are delegated to the Agent by
the terms thereof, together with such powers as are reasonably incidental
thereto; and (vii) such assignee agrees that it will perform in accordance with
their terms all of the obligations which by the terms of the Loan Documents
are required to be performed by it as a Lender.

     (c)     The Agent shall maintain at its address referred to in Section
9.02 a copy of each Lender Assignment delivered to and accepted by it and a
register for the recordation of the names and addresses of the Lenders and the
Commitment of, and principal amount of the Advances owing to, each Lender from
time to time (the "REGISTER").  The entries in the Register shall be
conclusive and binding for all purposes, absent manifest error, and the
Borrower, the Agent and the Lenders may treat each Person whose name is
recorded in the Register as a Lender hereunder for all purposes of this
Agreement.  The Register shall be available for inspection by the Borrower or
any Lender at any reasonable time and from time to time upon reasonable prior
notice.

     (d)     Upon its receipt of a Lender Assignment executed by an assigning
Lender and an assignee representing that it is an Eligible Assignee, together
with any Note or Notes subject to such assignment, the Agent shall, if such
Lender
<PAGE>
 
                                                                            62

Assignment has been completed and is in substantially the form of Exhibit C
hereto,  (i) accept such Lender Assignment, (ii) record the information
contained therein in the Register and (iii) give prompt notice thereof to the
Borrower.  Within 15 Business Days after its receipt of such notice, the
Borrower shall execute and deliver to the Agent in exchange for the surrendered
Note or Notes a new Note to such Eligible Assignee in an amount equal to the
Commitment assumed by it pursuant to such Lender Assignment and, if the
assigning Lender has retained a Commitment hereunder, a new Note to the
assigning Lender in an amount equal to the Commitment retained by it hereunder.
Such new Note or Notes shall be in an aggregate principal amount equal to the
aggregate principal amount of such surrendered Note or Notes and shall be dated
the effective date of such Lender Assignment and shall otherwise be in
substantially the form of Exhibit A hereto.

     (e)     Each Lender may sell participations to one or more banks,
financial institutions, or other entities in all or a portion of its rights
and obligations under the Loan Documents (including, without limitation, all
or a portion of its Commitment, the Advances owing to it and the Note or Notes
held by it); provided, however, that  (i) such Lender's obligations under this
Agreement (including, without limitation, its Commitment to the Borrower
hereunder) shall remain unchanged, (ii) such Lender shall remain solely
responsible to the other parties hereto for the performance of such
obligations, (iii) such Lender shall remain the holder of any such Note for all
purposes of this Agreement, (iv) the Borrower, the Agent and the other Lenders
shall continue to deal solely and directly with such Lender in connection with
such Lender's rights and obligations under this Agreement, (v) such Lender
shall not agree with any such participant (other than an Affiliate of such
Lender) that such Lender shall take directions from such participant with
respect to any action which such Lender shall be entitled to take or omit to
take hereunder or under or in respect of the other Loan Documents, other than,
in the case of a participant in an Advance or a Commitment, actions under
Section 2.18 and Section 9.01(a), (b), (c), (d), or (g), and (vi) such
participant shall be entitled to the cost protection provisions contained in
Sections 2.08 and 2.13 only if the Lender from which such participant acquired
its participation would have been entitled to such cost protection provisions
had such Lender not sold such participation hereunder.

     (f)     Any Lender may, in connection with any assignment or
participation or proposed assignment or participation pursuant to this Section
9.07, disclose to the assignee or participant or proposed assignee or
participant, any information relating to the Borrower furnished to such Lender
by or on behalf of the Borrower; provided, that, prior to any such disclosure,
the assignee or participant or proposed assignee or participant shall agree to
preserve the confidentiality of any confidential information received by it
from such Lender.
<PAGE>
 
                                                                            63

     (g)     If any Lender (or any bank, financial institution, or other
entity to which such Lender has sold a participation) shall (i) make any
demand for payment under Section 2.08 or 2.13, (ii) give notice to the Agent
pursuant to Section 2.14, (iii) either (A) not have outstanding unsecured
long-term indebtedness rated at or above "investment grade" by at least two of
Moody's, S&P and D&P, or (B) not have outstanding short-term unsecured
indebtedness rated at or above A-2, P-2, or D-2 by at least two of Moody's,
S&P and D&P, or (iv) determine not to extend the Termination Date in response
to any request by the Borrower pursuant to Section 2.18, then (1) in the case
of any demand made under clause (i) or the occurrence of the event described
in clause (ii), within 30 days after any such demand (if, but only if, in the
case of any demanded payment described in clause (i), such demanded payment
has been made by the Borrower), (1) in the case of the occurrence of any event
described in clause (iii), at any time thereafter, and (1) in the case of the
occurrence of any event described in clause (iv), at any time prior to the
then-scheduled Termination Date, the Borrower may, with the approval of the
Agent (which approval shall not be unreasonably withheld), and provided that
no Event of Default or Unmatured Default shall then have occurred and be
continuing, demand that such Lender assign in accordance with this Section
9.07 to one or more Eligible Assignees designated by the Borrower all (but not
less than all) of such Lender's Commitment and the Advances owing to it within
the period ending on the later to occur of the last day in the period
described in clause (1), (2), or (3), above, as applicable, and the last day
of the longest of the then current Interest Periods for such Advances.  If any
such Eligible Assignee designated by the Borrower shall fail to consummate
such assignment on terms acceptable to such Lender, or if the Borrower shall
fail to designate any such Eligible Assignees for all or part of such Lender's
Commitment or Advances, then such demand by the Borrower shall become
ineffective; it being understood for purposes of this subsection (g) that such
assignment shall be conclusively deemed to be on terms acceptable to such
Lender, and such Lender shall be compelled to consummate such assignment to an
Eligible Assignee designated by the Borrower, if such Eligible Assignee (x)
shall agree to such assignment by entering into a Lender Assignment with such
Lender, (y) shall offer compensation to such Lender in an amount equal to all
amounts then owing by the Borrower to such Lender hereunder and under the Note
made by the Borrower to such Lender, whether for principal, interest, fees,
costs or expenses (other than the demanded payment referred to above and
payable by the Borrower as a condition to the Borrower's right to demand such
assignment), or otherwise, and (z) shall pay to the Agent the $2,500
processing and recordation fee referred to in Section 9.07(a)(iii).

     SECTION 9.08.  WAIVER OF JURY TRIAL.  THE AGENT, THE LENDERS, THE LC BANKS
AND THE BORROWER HEREBY KNOWINGLY,
<PAGE>
 
                                                                            64

VOLUNTARILY AND INTENTIONALLY WAIVE ANY RIGHTS THEY MAY HAVE TO A TRIAL BY JURY
IN RESPECT OF ANY LITIGATION BASED HEREON, OR ARISING OUT OF, UNDER, OR IN
CONNECTION WITH, THIS AGREEMENT OR ANY OTHER LOAN DOCUMENT, OR ANY COURSE OF
CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN), OR ACTIONS
OF THE AGENT, SUCH LENDERS, SUCH LC BANKS OR THE BORROWER.  THIS PROVISION IS A
MATERIAL INDUCEMENT FOR THE AGENT, THE LC BANKS AND THE LENDERS ENTERING INTO
THIS AGREEMENT.

     SECTION 9.09.  CONSENT.  Unless otherwise specified as being within the
sole discretion of the Agent, the Lenders, the LC Banks, the Majority Lenders
or the Borrower, whenever the consent or approval of the Agent, the Lenders,
the Majority Lenders, or the Borrower, respectively, is required herein, such
consent or approval shall not be unreasonably withheld or delayed.

     SECTION 9.10.  GOVERNING LAW.  This Agreement and the other Loan
Documents shall be governed by, and construed in accordance with, the laws of
the State of New York.  Each of the Borrower, the Lenders, the LC Banks and
the Agent  (i) irrevocably submits to the non-exclusive jurisdiction of any
New York State Court or Federal court sitting in New York City in any action
arising out of any Loan Document, (ii) agrees that all claims in such action
may be decided in such court, (iii) waives, to the fullest extent it may
effectively do so, the defense of an inconvenient forum and any objection to
venue and (iv) consents to the service of process by mail.  A final judgment in
any such action shall be conclusive and may be enforced in other
jurisdictions.  Nothing herein shall affect the right of any party to serve
legal process in any manner permitted by law or affect its right to bring any
action in any other court.

     SECTION 9.11.  RELATION OF THE PARTIES; NO BENEFICIARY.  No term,
provision or requirement, whether express or implied, of any Loan Document, or
actions taken or to be taken by any party thereunder, shall be construed to
create a partnership, association, or joint venture between such parties or
any of them.  No term or provision of the Loan Documents shall be construed to
confer a benefit upon, or grant a right or privilege to, any Person other than
the parties thereto.

     SECTION 9.12.  EXECUTION IN COUNTERPARTS.  This Agreement may be executed
in any number of counterparts and by different parties hereto in separate
counterparts, each of which when so executed shall be deemed to be an original
and all of which taken together shall constitute one and the same agreement.
<PAGE>
 
                                                                            65

     SECTION 9.13.  SEVERABILITY.  Any provision of this Agreement or anyother
Loan Document that is prohibited, unenforceable or invalid in any jurisdiction
shall, as to such jurisdiction, be ineffective to the extent of such
prohibition, unenforceability or invalidity without invalidating the remaining
provisions hereof or thereof or affecting the validity, enforceability or
legality of such provision in any other jurisdiction.

     SECTION 9.14.  HEADINGS.  Article and Section headings and the Table of
Contents used herein are for convenience of reference only, are not part of
this Agreement and are not to affect the construction of, or to be taken into
consideration in interpreting, this Agreement.

     SECTION 9.15.  ENTIRE AGREEMENT.  This Agreement, the Exhibits and
Schedules hereto and the other Loan Documents constitute the entire agreement
and understanding among the parties hereto and thereto relative to the subject
matter hereof and thereof.  Any previous agreement among the parties with
respect to the subject matter hereof and thereof is superseded by this
Agreement, the Exhibits and Schedules hereto and the other Loan Documents.
Nothing in this Agreement or in the other Loan Documents, expressed or implied,
is intended to confer upon any party other than the parties hereto and thereto
any rights, remedies, obligations, or liabilities under or by reason of this
Agreement or the other Loan Documents.
<PAGE>
 
                                                                            66

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


                    UNICOM ENTERPRISES INC.




                    By Dennis F. O'Brien
                       ----------------------------
                       Name: Dennis F. O'Brien
                       Title:   Treasurer


                    CITIBANK, N.A., as Agent




                    By Anita J. Brickell
                       ----------------------------
                       Name:  Anita J. Brickell
                       Title:    Attorney-in-Fact
<PAGE>
 
                                   SCHEDULE I

                            UNICOM ENTERPRISES INC.


     Amended and Restated Credit Agreement, dated as of November 15, 1996,
                         among Unicom Enterprises Inc.,
 the Banks listed therein and other Lenders from time to time parties thereto,
                          and Citibank, N.A., as Agent




                             Domestic                Eurodollar
Name of Lender               Lending Office          Lending Office
--------------               --------------          --------------
<PAGE>
 
                                   EXHIBIT A

                                  FORM OF NOTE



U.S.$______________                                    Dated: _________, 19__




     FOR VALUE RECEIVED, the undersigned, UNICOM ENTERPRISES INC., an Illinois
corporation (the "BORROWER"), HEREBY PROMISES TO PAY to the order of
___________________________ (the "LENDER") for the account of its Applicable
Lending Office (such term and other capitalized terms herein being used as
defined in the Credit Agreement referred to below) the principal sum of
U.S.$[amount of the Lender's Commitment in figures] or, if less, the aggregate
principal amount of the Advances made by the Lender to the Borrower pursuant
to the Credit Agreement outstanding on the Termination Date.

     The Borrower promises to pay interest on the unpaid principal amount of
each Advance from the date of such Advance until such principal amount is paid
in full, at such interest rates, and payable at such times, as are specified
in the Credit Agreement.

     Both principal and interest are payable in lawful money of the United
States of America to Citibank, N.A., as Agent, at 399 Park Avenue, New York,
New York 10043, in same day funds.  Each Advance made by the Lender to the
Borrower pursuant to the Credit Agreement, and all payments made on account of
principal thereof, shall be recorded by the Lender and, prior to any transfer
hereof, endorsed on the grid attached hereto which is part of this Promissory
Note, provided that the failure to so record any Advance or any payment on
account thereof shall not affect the payment obligations of the Borrower
hereunder or under the Credit Agreement.

     This Promissory Note is one of the Notes referred to in, and is entitled
to the benefits of, the Amended and Restated Credit Agreement, dated as of
November 15, 1996  (as amended, modified or supplemented from time to time, the
"CREDIT AGREEMENT"), among the Borrower, the Lender and certain other banks
parties thereto, and Citibank, N.A., as Agent for the Lender and such other
banks.  The Credit Agreement, among other things, (i) provides for the making
of Advances by the Lender to the Borrower from time to time in an aggregate

                                       ii
<PAGE>
 
amount not to exceed at any time outstanding the U.S. dollar amount first above
mentioned, the indebtedness of the Borrower resulting from each such Advance
being evidenced by this Promissory Note, and (ii) contains provisions for
acceleration of the maturity hereof upon the happening of certain stated events
and also for prepayments on account of principal hereof prior to the maturity
hereof upon the terms and conditions therein specified.

     The Borrower hereby waives presentment, demand, protest and notice of any
kind.  No failure to exercise, and no delay in exercising, any rights
hereunder on the part of the holder hereof shall operate as a waiver of such
rights.

     THIS PROMISSORY NOTE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE
WITH, THE LAWS OF THE STATE OF NEW YORK.


                                         UNICOM ENTERPRISES INC.





                                        By
                                           -------------------------------
                                           Name:
                                           Title:



                                      iii
<PAGE>
 
      ADVANCES, INTEREST PERIODS AND PAYMENTS OF PRINCIPAL
-------------------------------------------------------------------

                      Interest                      Amount of
                      Period          Principal     Unpaid
        Amount of     (if any) of     Paid or       Principal     Notation
Date    Advance       Advance         Prepaid       Balance       Made By

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

-------------------------------------------------------------------

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<PAGE>
 
                                  EXHIBIT B-1

                          FORM OF NOTICE OF BORROWING




Citibank, N.A., as Agent
  for the Lenders parties
  to the Credit Agreement
  referred to below
399 Park Avenue
New York, New York 10043


                                                 [Date]


     Attention:     Utilities Department
                    North American Finance Group


Ladies and Gentlemen:

     The undersigned, Unicom Enterprises Inc., refers to the Amended and
Restated Credit Agreement, dated as of November 15, 1996 (as amended, modified
or supplemented from time to time, the "CREDIT AGREEMENT", the terms defined
therein being used herein as therein defined), among the undersigned, certain
Lenders parties thereto and Citibank, N.A., as Agent for said Lenders, and
hereby gives you notice, irrevocably, pursuant to Section 2.02 of the Credit
Agreement that the undersigned hereby requests a Borrowing under the Credit
Agreement, and in that connection sets forth below the information relating to
such Borrowing (the "PROPOSED BORROWING") as required by Section 2.02(a) of
the Credit Agreement:

              (i)     The Business Day of the Proposed Borrowing is
     __________________, 19__.

             (ii)     The Type of Advances to be made in connection with the
     Proposed Borrowing is [Alternate Base Rate Advances] [Eurodollar Rate
     Advances].

                                       ii
<PAGE>
 
             (iii)   The aggregate principal amount of the Proposed Borrowing
     is $____________.

             [(iv)   The Interest Period for each Advance made as part of the
     Proposed Borrowing is ____ month[s].]*

     The undersigned hereby certifies that the following statements are true
on the date hereof, and will be true on the date of the Proposed Borrowing:

             (A)     the representations and warranties contained in Section
     5.01 of the Credit Agreement are true and correct, before and after giving
     effect to the Proposed Borrowing and to the application of the proceeds
     thereof, as though made on and as of such date; and

             (B)     no event has occurred and is continuing, or would result
     from such Proposed Borrowing or from the application of the proceeds
     thereof, that constitutes an Event of Default or Unmatured Default.


                                   Very truly yours,

                                   UNICOM ENTERPRISES INC.



                                   By
                                      -------------------------------
                                      Name:
                                      Title:



-----------------------------
*For Eurodollar Rate Advances only.

                                      iii
<PAGE>
 
                                  EXHIBIT B-2

                          FORM OF NOTICE OF CONVERSION


Citibank, N.A., as Agent
  for the Lenders parties
  to the Credit Agreement
  referred to below
399 Park Avenue
New York, New York 10043


                                                 [Date]


     Attention:     Utilities Department
                    North American Finance Group


Ladies and Gentlemen:

     The undersigned, Unicom Enterprises Inc., refers to the Amended and
Restated Credit Agreement, dated as of November 15, 1996 (as amended, modified
or supplemented from time to time, the "CREDIT AGREEMENT", the terms defined
therein and not otherwise defined herein being used herein as therein
defined), among the Borrower, the Lenders named therein and the Agent, and
hereby gives you notice, irrevocably, pursuant to Section 2.10 of the Credit
Agreement that the undersigned hereby requests a Conversion under the Credit
Agreement, and in that connection sets forth below the information relating to
such Conversion (the "PROPOSED CONVERSION") as required by Section 2.10 of the
Credit Agreement:

                 (i)     The Business Day of the Proposed Conversion
        is ______________________, ________.

                (ii)     The Type of Advances to be subject to the Proposed
        Conversion is [Alternate Base Rate Advances] [Eurodollar Rate
        Advances].

               (iii)     The aggregate principal amount of the Advances to be
        subject to the Proposed Conversion is  $ _________________ .

                                       iv
<PAGE>
 
                (iv)     The Type of Advances to which such Advances are
        proposed to be Converted is [Alternate Base Rate Advances] [Eurodollar
        Rate Advances].

                [(v)     The Interest Period for each Advance made as part of
        the Proposed Conversion is ____ month(s).]**

     The undersigned hereby certifies that the Borrower's request for the
Proposed Conversion is made in compliance with Sections 2.01, 2.09 and 2.10 of
the Credit Agreement.

     The undersigned hereby further certifies that the following statements
are true on the date hereof, and will be true on the date of the Proposed
Conversion:

                (i)     The representations and warranties contained in Section
        5.01 of the Credit Agreement (other than those contained in subsections
        (e) and (f) thereof) and in Section 6 of the Guaranty (other than those
        contained in subsections (f) and (g) thereof) are true and correct,
        before and after giving effect to the Proposed Conversion, as though
        made on and as of such date; and

                (ii)     No Unmatured Default or Event of Default has occurred
        and is continuing, or would result from the Proposed Conversion.

                                   Very truly yours,

                                   UNICOM ENTERPRISES INC.


                                   By
                                      --------------------------
                                      Title:





------------------------------
**Delete for Base Rate Advances

                                       v
<PAGE>
 
                                   EXHIBIT C


                           FORM OF LENDER ASSIGNMENT


                           ASSIGNMENT AND ACCEPTANCE

                            Dated ___________, 19__




     Reference is made to the Amended and Restated Credit Agreement, dated as
of November 15, 1996 (as amended, modified or supplemented from time to time,
the "CREDIT AGREEMENT"), among Unicom Enterprises Inc., an Illinois
corporation (the "BORROWER"), the Lenders named therein and from time to time
parties thereto and Citibank, N.A., as Agent for the Lenders (the "Agent").
Terms defined in the Credit Agreement and not otherwise defined herein are
used herein with the same meaning.

     _____________ (the "ASSIGNOR") and ____________ (the "ASSIGNEE") agree as
follows:

     (1)     The Assignor hereby sells and assigns without recourse to the
Assignee, and the Assignee hereby purchases and assumes from the Assignor,
that interest in and to all of the Assignor's rights and obligations under the
Credit Agreement as of the date hereof which represents the percentage
interest specified on Schedule 1 of all outstanding rights and obligations
under the Credit Agreement, including, without limitation, such interest in
the Assignor's Commitment, the Advances owing to the Assignor, the Assignor's
participation in Letters of Credit, and the Note[s] held by the Assignor.
After giving effect to such sale and assignment, the Assignee's Commitment and
the amount of the Advances owing to the Assignee will be as set forth in
Section 2 of Schedule 1.

     (2)     The Assignor (i) represents and warrants that it is the legal and
beneficial owner of the interest being assigned by it hereunder and that such
interest is free and clear of any adverse claim; (ii) makes no representation
or warranty and assumes no responsibility with respect to any statements,
warranties or representations made in or in connection with any Loan Document
or any other instrument or document furnished pursuant thereto or the
execution, legality, validity, enforceability, genuineness, sufficiency or
value of any Loan Document

                                       vi
<PAGE>
 
or any other instrument or document furnished pursuant thereto; (iii) makes no
representation or warranty and assumes no responsibility with respect to the
financial condition of the Borrower or the performance or observance by the
Borrower of any of its obligations under the Credit Agreement or any other
instrument or document furnished pursuant thereto; and (iv) attaches the Note[s]
referred to in paragraph 1 above and requests that the Agent exchange such
Note[s] for a new Note payable to the order of the Assignee in an amount equal
to the Commitment assumed by the Assignee pursuant hereto or new Notes payable
to the order of the Assignee in an amount equal to the Commitment assumed by
the Assignee pursuant hereto and the Assignor in an amount equal to the
Commitment retained by the Assignor under the Credit Agreement, respectively,
as specified on Schedule 1 hereto.

     (3)     The Assignee (i) confirms that it has received a copy of the
Credit Agreement, together with copies of the financial statements referred to
in Section 5.01(e) thereof and such other documents and information as it has
deemed appropriate to make its own credit analysis and decision to enter into
this Assignment and Acceptance; (ii) agrees that it will, independently and
without reliance upon the Agent, the Assignor or any other Lender and based on
such documents and information as it shall deem appropriate at the time,
continue to make its own credit decisions in taking or not taking action under
the Credit Agreement; (iii) confirms that it is an Eligible Assignee; (iv)
appoints and authorizes the Agent to take such action as agent on its behalf
and to exercise such powers under the Credit Agreement as are delegated to the
Agent by the terms thereof, together with such powers as are reasonably
incidental thereto; (v) agrees that it will perform in accordance with their
terms all of the obligations which by the terms of the Credit Agreement are
required to be performed by it as a Lender; [and] (vi) specifies as its
Domestic Lending Office (and address for notices) and Eurodollar Lending
Office the offices set forth beneath its name on the signature pages hereof
[and (vi) attaches the forms prescribed by the Internal Revenue Service of the
United States certifying that it is exempt from United States withholding
taxes with respect to all payments to be made to the Assignee under the Credit
Agreement and the Notes].***

     (4)     Following the execution of this Assignment and Acceptance by the
Assignor, the Assignee and, if required pursuant to Section 9.07(a) of the
Credit Agreement, the Borrower, it will be delivered to the Agent for
acceptance and recording by the Agent.  The effective date of this Assignment
and Acceptance shall be the date of acceptance thereof by the Agent, unless
otherwise specified on Schedule 1 hereto (the "EFFECTIVE ASSIGNMENT DATE").


---------------------
*** If the Assignee is organized under the laws of a jurisdiction outside the
United States.

                                      vii
<PAGE>
 
     (5)     Upon such acceptance and recording by the Agent, as of the
Effective Assignment Date, (i) the Assignee shall be a party to the Credit
Agreement and, to the extent provided in this Assignment and Acceptance, have
the rights and obligations of a Lender thereunder and (ii) the Assignor shall,
to the extent provided in this Assignment and Acceptance, relinquish its
rights and be released from its obligations under the Credit Agreement.

     (6)     Upon such acceptance and recording by the Agent, from and after
the Effective Assignment Date, the Agent shall make all payments under the
Credit Agreement and the Notes in respect of the interest assigned hereby
(including, without limitation, all payments of principal, interest and fees
with respect thereto) to the Assignee.  The Assignor and Assignee shall make
all appropriate adjustments in payments under the Credit Agreement and the
Notes for periods prior to the Effective Assignment Date directly between
themselves.

     (7)     This Assignment and Acceptance shall be governed by, and
construed in accordance with, the laws of the State of New York.

     IN WITNESS WHEREOF, the parties hereto have caused this Assignment and
Acceptance to be executed by their respective officers thereunto duly
authorized, as of the date first above written, such execution being made on
Schedule 1 hereto.

                                      viii
<PAGE>
 
                                   Schedule 1
                                       to
                           Assignment and Acceptance

                             Dated __________, 19__


Section 1.
----------

     Percentage Interest:                                    ____ %

Section 2.
----------

     Assignee's Commitment:                                 $____

     Aggregate Outstanding Principal
       Amount of Advances owing to the Assignee:            $____

     A Note payable to the order of the Assignee
                           Dated:   _________, 19__

                                     Principal amount:      $____

     A Note payable to the order of the Assignor
                           Dated:   _________, 19__

                                     Principal amount:      $____

Section 3.
----------

     Effective Assignment Date*:          _________, 19__


                         [NAME OF ASSIGNOR]




-------------------
* This date should be no earlier than the date of acceptance by the Agent.
<PAGE>
 
                         [NAME OF ASSIGNEE]



                         By _____________________________
                            Name:
                            Title:


                         Domestic Lending Office (and
                           address for notices):
                                [Address]

                         Eurodollar Lending Office:
                                [Address]

Consented to as of the
date first above written:

UNICOM ENTERPRISES INC.




By ________________________________
   Name:
   Title:


Accepted this ____ day
of ____________, 19__

CITIBANK, N.A.


By ________________________________
   Name:
   Title:



                                       ii
<PAGE>
 
     EXHIBIT D


                           FORM OF LC BANK AGREEMENT



     LETTER OF CREDIT BANK AGREEMENT (the "AGREEMENT"), dated as of
__________, 19___, between UNICOM ENTERPRISES INC., an Illinois corporation
(the "BORROWER"), and _____________________ (the "LC BANK").


                             PRELIMINARY STATEMENTS

     (1)     The Borrower has entered into an Amended and Restated Credit
Agreement, dated as of November 15, 1996 (said agreement, as amended, modified
or supplemented from time to time, being the "CREDIT AGREEMENT"), with certain
lenders named therein and from time to time parties thereto (the "LENDERS")
and Citibank, N.A., as Agent.  Unless otherwise defined herein, capitalized
terms used herein shall have the meanings assigned to such terms in the Credit
Agreement.

     (2)     Pursuant to Section 3.01 of the Credit Agreement, the Borrower
may from time to time identify and arrange for one or more Lenders to act as
an LC Bank thereunder and issue one or more Letters of Credit (as defined
below) in an aggregate stated amount not exceeding $100,000,000.  The Borrower
desires to designate ________________ as an LC Bank under the Credit
Agreement.  Subject to the terms and conditions hereof and of the Credit
Agreement, ______________ has agreed to act as an LC Bank and to issue an
irrevocable letter of credit in favor of ________________________ (the
"BENEFICIARY") in the amount of $__________ (the "LC COMMITMENT") for the
account of the Borrower.

     (3)     [PURPOSE OF THE LETTER OF CREDIT TO BE ISSUED HEREUNDER.]

     NOW, THEREFORE, in consideration of the premises and in order to induce
the LC Bank to issue the Letter of Credit, the parties hereto agree as
follows:




                                      iii
<PAGE>
 
                                   ARTICLE I
                                  DEFINITIONS


     SECTION 1.01.  CERTAIN DEFINED TERMS.  As used in this Agreement, the
following terms shall have the following meanings (such meanings to be equally
applicable to both the singular and plural forms of the terms defined):

             "BENEFICIARY" has the meaning assigned to that term in Preliminary
        Statement (2).

             "ISSUANCE TERMINATION DATE" has the meaning assigned to that term
        in Section 3.01 hereof.

             "LC COMMITMENT" has the meaning assigned to that term in
        Preliminary Statement (2).

             "LETTER OF CREDIT" means the letter of credit issued by the LC
        Bank pursuant to Section 3.02 hereof, as such letter of credit may from
        time to time be amended, modified or extended in accordance with the
        terms of the Credit Agreement and this Agreement, in form and substance
        satisfactory to the LC Bank, the Borrower and the Agent.

             "STATED TERMINATION DATE" means ___________________________;
        provided, however, that the Stated Termination Date of the Letter of
        Credit upon its date of issuance shall be no later than the latest
        then-scheduled Termination Date; and provided further, however, that if
        the aggregate amount of the Commitments on any scheduled Termination
        Date (after giving effect to any scheduled reductions in the
        Commitments on such date) will be less than the LC Commitment, the
        Stated Termination Date of the Letter of Credit shall be no later than
        such Termination Date.

     SECTION 1.02.  COMPUTATION OF TIME PERIODS.  Computation of a period of 
time from a specified date to a later specified date shall be made in accordance
with the Credit Agreement.

     SECTION 1.03.  ACCOUNTING TERMS.  All accounting terms not specifically
defined herein or in the Credit Agreement shall be construed in accordance
with generally accepted United States accounting principles as in effect as of
the date hereof consistently applied, except as otherwise stated herein.

                                       iv
<PAGE>
 
                                   ARTICLE II
                              THE CREDIT AGREEMENT


     SECTION 2.01.  CREDIT AGREEMENT.  a. The parties hereto acknowledge and
agree that this Agreement is an "LC Bank Agreement" under the Credit
Agreement, and that the parties hereto shall be entitled to the rights and
remedies, and bound by the obligations, accorded to the parties in interest to
an "LC Bank Agreement" as so provided in the Credit Agreement.  The parties
hereto hereby further acknowledge and agree that the Agent, the Lenders and
the Beneficiary, as the case may be, are intended third-party beneficiaries
hereof and are entitled (acting through the Agent, in the case of the Lenders)
to the rights and benefits accorded hereunder.

     b.     The LC Bank hereby acknowledges and agrees that it is an "LC Bank"
under the Credit Agreement, that, by its execution and delivery hereof, it is
deemed a party to the Credit Agreement as if it were a signatory thereof in
such capacity and that it assumes all obligations, and acquires all rights and
remedies, of an "LC Bank" under the Credit Agreement.

     c.     In the event of any conflict between the terms of this Agreement
and the Credit Agreement (unless such conflict arises solely as a result of an
amendment to the Credit Agreement made after the date hereof without the
written consent of the LC Bank thereto), the terms of the Credit Agreement
shall control and such conflicting terms hereunder shall be of no force or
effect.


                                  ARTICLE III
                         AMOUNT AND TERMS OF THE LETTER
                                   OF CREDIT


     SECTION 3.01.  THE LETTER OF CREDIT.  The LC Bank agrees, on the terms and
conditions hereinafter set forth, and subject, at all times, to Sections
3.01(b) and 2.12(a) of the Credit Agreement, to issue the Letter of Credit to
the Beneficiary on any Business Day during the period from the date hereof to
and including ________________, 19__ (the "ISSUANCE TERMINATION DATE") in an
amount not to exceed the LC Commitment and expiring on or before the Stated
Termination Date.

     SECTION 3.02.  ISSUING THE LETTER OF CREDIT.  The Letter of Credit shall be
issued (or the stated maturity thereof extended or terms thereof modified or

                                       v
<PAGE>
 
amended) on not less than three Business Days' prior written notice thereof to
the Agent and the LC Bank pursuant to, and in accordance with, Section 3.02 of
the Credit Agreement.

     SECTION 3.03.  FEES.

     (a).     The Borrower hereby agrees to pay to the LC Bank, upon the
issuance of the Letter of Credit hereunder, an issuance fee in an amount equal
to [___% of the initial stated amount thereof] [$________].

     (b).     The Borrower hereby agrees to pay to the LC Bank, upon each
drawing made by the Beneficiary under the Letter of Credit, a drawing fee in
an amount equal to $______.

     (c).     The Borrower hereby agrees to pay to the LC Bank, upon each
amendment to the Letter of Credit, an amendment fee in an amount equal to
$______.

     [(d).    The Borrower hereby agrees to pay to the LC Bank a fronting fee
equal to ___% of the average daily amount of the stated amount of the Letter
of Credit from the date of issuance of the Letter of Credit until the date of
expiry of the Letter of Credit, payable on the last day of each __________,
__________, __________ and __________ during such period and on such date of
expiry.]

     SECTION 3.04.  PAYMENTS AND COMPUTATIONS.  The Borrower shall make each
payment hereunder not later than 12:00 noon (New York City time) on any day
when due in U.S. Dollars.  Any such payment shall be made to the Agent for the
account of the LC Bank at the Agent's office set forth in Section 9.02 of the
Credit Agreement.  The Borrower hereby authorizes the LC Bank, if and to the
extent payment is not made when due hereunder, to charge from time to time
against any or all of the Borrower's accounts with the LC Bank any amount so
due.  Computations of the fees hereunder shall be made by the LC Bank on the
basis of a year of 360 days for the actual number of days (including the first
day but excluding the last day) elapsed.

     SECTION 3.05.  EXTENSION OF THE STATED TERMINATION DATE.  At least 30 but
not more than 60 days before the Stated Termination Date of the Letter of
Credit, the Borrower may request the LC Bank in writing (with a copy of each
such request to the Agent) to extend the Stated Termination Date of the Letter
of Credit for purposes of this Agreement and the Letter of Credit to any date
not later than the then-scheduled Termination Date. If the Borrower shall make
such a request, the LC Bank shall, on or before the 15th Business Day after its
receipt of such
                                       vi
<PAGE>
 
request, notify the Borrower in writing whether or not the LC Bank consents to
such request and, if the LC Bank does so consent, the conditions of such
consent (including conditions relating to legal documentation and the consent
of the Beneficiary thereof).  If the LC Bank shall not so notify the Borrower,
the LC Bank shall be deemed not to have consented to such request.  Any such
extension shall be effective only if and when made in accordance with Articles
III and IV of the Credit Agreement.


                                   ARTICLE IV
                             CONDITIONS OF ISSUANCE


     SECTION 4.01.  CONDITIONS PRECEDENT TO ISSUANCE OF THE LETTER OF CREDIT.
The obligation of the LC Bank to issue the Letter of Credit is subject to the
satisfaction of the applicable conditions precedent set forth in Article IV of
the Credit Agreement.


                                   ARTICLE V
                         REPRESENTATIONS AND WARRANTIES


     SECTION 5.01.  REPRESENTATIONS AND WARRANTIES OF THE BORROWER.  The 
Borrower hereby represents and warrants for the benefit of the LC Bank that the
representations and warranties of the Borrower set forth in Article V of the
Credit Agreement are true and correct on the date hereof, on each date of
issuance of the Letter of Credit and on each date on which the term thereof is
extended in accordance with Section 3.05 hereof, as if made on and as of such
date.


                                   ARTICLE VI
                                 MISCELLANEOUS


     SECTION 6.01.  AMENDMENTS, ETC.  No amendment or waiver of any provision of
this Agreement, nor consent to any departure by the Borrower therefrom, shall
in any event be effective unless the same shall be in writing, signed by the
LC Bank and the Borrower and consented to by the Agent on behalf of the
Majority Lenders, and then such waiver or consent shall be effective only in
the specific instance and for the specific purpose for which given.

                                      vii
<PAGE>
 
     SECTION 6.02.  NOTICES, ETC.  All notices and other communications provided
for hereunder shall be made in accordance with Section 9.02 of the Credit
Agreement and sent, if to the LC Bank, at its address set forth on the
signature page hereof.

     SECTION 6.03.  NO WAIVER; REMEDIES.  No failure on the part of the Borrower
or LC Bank to exercise, and no delay in exercising, any right hereunder or
under the Credit Agreement shall operate as a waiver thereof; nor shall any
single or partial exercise of any right hereunder or thereunder preclude any
other or further exercise thereof or the exercise of any other right.  The
remedies herein and therein provided are cumulative and not exclusive of any
remedies provided by law.

     SECTION 6.04.  COSTS, EXPENSES AND TAXES.  The Borrower agrees to pay on
demand all costs and expenses incurred by the LC Bank, including, without
limitation, the reasonable counsel fees and expenses of counsel to the LC
Bank, in connection with the preparation, execution, delivery and
administration of this Agreement and any other documents that may be delivered
in connection with this Agreement and any proposed modification, amendment or
consent relating to this Agreement, including, without limitation, fees and
out-of-pocket expenses of counsel for the LC Bank with respect thereto and
with respect to advising the LC Bank as to its rights and responsibilities
under this Agreement.  The Borrower further agrees to pay on demand all costs
and expenses, if any (including, without limitation, counsel fees and expenses
of outside counsel and of internal counsel), incurred by the LC Bank in
connection with (i) the enforcement (whether through negotiations, legal
proceedings or otherwise) of this Agreement and such other documents that may
be delivered in connection with this Agreement and (ii) any action or
proceeding relating to a court order, injunction, or other process or decree
restraining or seeking to restrain the LC Bank from paying any amount under
the Letter of Credit.  In addition, the Borrower shall pay any and all stamp
and other taxes and fees payable or determined to be payable in connection
with the execution and delivery of this Agreement or the Letter of Credit or
any such other documents, and agrees to save the LC Bank harmless from and
against any and all liabilities with respect to or resulting from any delay in
paying or omission to pay such taxes and fees.

     SECTION 6.05.  BINDING EFFECT.  This Agreement shall become effective when
it shall have been executed by the Borrower and the LC Bank and consented to
in writing by the Agent (for itself as the Agent and on behalf of the
Lenders); and thereafter shall be binding upon and inure to the benefit of the
Borrower, the LC Bank, the Agent, the Lenders and their respective successors
and assigns, except that the Borrower shall not have the right to assign its
rights hereunder or

                                      viii
<PAGE>
 
any interest herein without the prior written consent of the Lenders and the LC
Bank shall not have the right to assign its rights hereunder or any interest
herein without the prior written consent of the Lenders.

     SECTION 6.06.  SEVERABILITY.  Any provision of this Agreement which is
prohibited, unenforceable or not authorized in any jurisdiction shall, as to
such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of
such provision in any other jurisdiction.

     SECTION 6.07.  WAIVER OF JURY TRIAL.  EACH OF THE LC BANK AND THE BORROWER
HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING
OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE LETTER OF
CREDIT, OR ANY OTHER INSTRUMENT OR DOCUMENT DELIVERED HEREUNDER OR THEREUNDER.

     SECTION 6.08.  GOVERNING LAW; SUBMISSION TO JURISDICTION.  This Agreement
shall be governed by, and construed in accordance with, the laws of the State
of New York.  Each of the Borrower and the LC Bank (i) irrevocably submits to
the jurisdiction of any New York State court or Federal court sitting in New
York City in any action arising out of this Agreement or the Letter of Credit,
(ii) agrees that all claims in such action may be decided in such court, (iii)
waives, to the fullest extent it may effectively do so, the defense of an
inconvenient forum and any objections to venue and (iv) consents to the
service of process by mail.  A final judgment in any such action shall be
conclusive and may be enforced in other jurisdictions.  Nothing herein shall
affect the right of any party to serve legal process in any manner permitted
by law or affect its right to bring any action in any other court.

     SECTION 6.09.  HEADINGS.  Section headings in this Agreement are included
herein for convenience of reference only and shall not constitute a part of
this Agreement for any other purpose.

     SECTION 6.10.  EXECUTION IN COUNTERPARTS.  This Agreement may be executed
and consented to in any number of counterparts and by different parties hereto
in separate counterparts, each of which when so executed or consented to shall
be deemed to be an original and all of which taken together shall constitute
one and the same instrument.

                                       ix
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed and delivered by their respective officers thereunto duly
authorized as of the date first above written.

                         UNICOM ENTERPRISES INC.




                          By
                             ------------------------------------
                             Name:
                             Title:


                         [INSERT LC BANK], as LC Bank




                          By
                             ------------------------------------
                             Name:
                             Title:


Consented to as of the date
first above written:

CITIBANK, N.A., as Agent on
  behalf of the Lenders




By
   ----------------------
   Name:
   Title:





                                       x
<PAGE>
 
EXHIBIT E


                                FORM OF GUARANTY


     AMENDED AND RESTATED GUARANTY, dated as of November 15, 1996, made by
UNICOM CORPORATION, a corporation organized and existing under the laws of the
State of Illinois (the "GUARANTOR"), in favor of the Lenders (the "LENDERS")
and the LC Banks parties to the Credit Agreement (as defined below) and
Citibank, N.A., as agent (in such capacity, the "AGENT") for the Lenders.


                             PRELIMINARY STATEMENTS

     (1)     The Lenders and the Agent have entered into an Amended and
Restated Credit Agreement, dated as of the date hereof (said Agreement, as it
may hereafter be amended or otherwise modified from time to time, being the
"CREDIT AGREEMENT", the terms defined therein and not otherwise defined herein
being used herein as therein defined), with Unicom Enterprises Inc., a
corporation organized and existing under the laws of the State of Illinois
(the "BORROWER").  The Guarantor will derive substantial direct and indirect
benefit from the transactions contemplated by the Credit Agreement, the Notes
and the other Loan Documents.

     (2)     The Borrower is a wholly-owned Subsidiary of the Guarantor.

     (3)     It is a condition precedent to the making of Advances by the
Lenders under the Credit Agreement and the issuance of Letters of Credit by
the LC Banks pursuant to the Credit Agreement that the Guarantor shall have
executed and delivered this Guaranty.

     NOW, THEREFORE, in consideration of the premises and in order to induce
the Lenders to make Advances and each LC Bank to issue Letters of Credit under
the Credit Agreement, the Guarantor hereby agrees as follows:

     SECTION 1.  CERTAIN DEFINED TERMS.  As used in this Guaranty, the
following terms shall have the following meanings (such meanings to be equally
applicable to both the singular and plural forms of the terms defined):

                                       xi
<PAGE>
 
     "CONSOLIDATED CAPITALIZATION" means, at any date of determination, the
sum of (i) common equity of the Guarantor and its Consolidated Subsidiaries,
(ii) preferred and preference stock of the Guarantor and its Consolidated
Subsidiaries, (iii) Consolidated Debt of the Guarantor and its Consolidated
Subsidiaries and (iv) without duplication, Subordinated Deferrable Securities
Obligations.

     "CONSOLIDATED DEBT" means, at any date of determination, the sum of Debt
of the Guarantor and its Consolidated Subsidiaries and Contingent Obligations
of the Guarantor and its Consolidated Subsidiaries, excluding, however,
Subordinated Deferrable Securities Obligations.

     "CONSOLIDATED SUBSIDIARY" means, as to any Person, any Subsidiary of such
Person whose accounts are or are required to be consolidated with the accounts
of such Person in accordance with GAAP.

     "CONTINGENT OBLIGATION" means, as to any Person, the undrawn face amount
of any letters of credit issued for the account of such Person and shall also
mean any monetary obligation of such Person guaranteeing or in effect
guaranteeing any Debt, leases, dividends, letters of credit, or other
obligations ("primary obligations") of any other Person (the "primary
obligor") in any manner, whether directly or indirectly, including, without
limitation, any obligation of such Person, whether or not contingent, (a) to
purchase any such primary obligation or any property constituting direct or
indirect security therefor, (b) to advance or supply funds (i) for the
purchase or payment of any such primary obligation or (ii) to maintain working
capital or equity capital of the primary obligor or otherwise to maintain the
net worth or solvency of the primary obligor, (c) to purchase property,
securities, or services primarily for the purpose of assuring the obligee
under any such primary obligation of the ability of the primary obligor to
make payment of such primary obligation, or (d) otherwise to assure or hold
harmless the obligee under such primary obligation against loss in respect
thereof; provided, however, that the term Contingent Obligation shall not
include endorsements of instruments for deposit or collection in the ordinary
course of business.  The amount of any Contingent Obligation shall be deemed
to be an amount equal to the stated or determinable amount of the primary
obligation or, where such Contingent Obligation is specifically limited to a
portion of any such primary obligation, that portion to which it is limited
or, if not stated or determinable, the maximum reasonably anticipated
liability in respect thereof (assuming such Person is required to perform
thereunder) as determined by such Person in good faith.  For purposes of
computing the

                                      xii
<PAGE>
 
consolidated Debt of any Person, the amount of any primary obligation of any
Subsidiary of such Person and the amount of any Contingent Obligation of such
Person corresponding to such primary obligation shall only be counted once
(i.e., without duplication).

     "SUBORDINATED DEFERRABLE SECURITIES OBLIGATIONS" means all obligations of
the Guarantor and its Subsidiaries in respect of "ComEd- Obligated Mandatorily
Redeemable Preferred Securities of Subsidiary Trust", as set forth from time
to time in the consolidated balance sheets of the Guarantor and its
Consolidated Subsidiaries delivered pursuant to Section 7(a) hereof.

     "TANGIBLE NET WORTH" means, at any time of determination, with respect to
any Person, the excess of such Person's total assets over its total
liabilities, with total assets and total liabilities each to be determined in
accordance with GAAP consistently applied, excluding, however, from the
determination of total assets (i) goodwill, organizational expenses, research
and development expenses, trademarks, trade names, copyrights, patents, patent
applications, licenses and rights in any thereof, and other similar
intangibles, (ii) all prepaid expenses, deferred charges or unamortized debt
discount and expense, (iii) all reserves carried and not deducted from assets,
(iv) securities that are not readily marketable, (v) cash held in a sinking or
other analogous fund established for the purpose of redemption, retirement or
prepayment of capital stock or Debt, (vi) any write-up in the book value of
any asset resulting from a revaluation thereof subsequent to September 30,
1994, and (vii) any items not included in clauses (i) through (vi), above,
that are treated as intangibles in conformity with GAAP.

     SECTION 2.  GUARANTY.  The Guarantor hereby absolutely, unconditionally
and irrevocably guaranties the punctual payment when due, whether at stated
maturity, by acceleration or otherwise, of all obligations of the Borrower now
or hereafter existing under the Credit Agreement, the Notes and any other Loan
Documents, whether for principal, reimbursement obligations, interest, fees,
expenses or otherwise (all such obligations being the "OBLIGATIONS"), and
agrees to pay any and all expenses (including counsel fees and expenses)
incurred by the Agent, the LC Banks or the Lenders in enforcing any rights
under this Guaranty.  Without limiting the generality of the foregoing, the
Guarantor's liability shall extend to all amounts that constitute part of the
Obligations and would be owed by the Borrower to the Agent, the LC Banks or
the Lenders under the Credit Agreement, the Notes and the other Loan Documents
but for the fact that they are unenforceable or not allowable due to the
existence of a bankruptcy, reorganization or similar proceeding involving the
Borrower.

                                      xiii
<PAGE>
 
     SECTION 3.  GUARANTY ABSOLUTE.  The Guarantor guarantees that the
Obligations will be paid strictly in accordance with the terms of the Credit
Agreement, the Notes and the other Loan Documents, regardless of any law,
regulation or order now or hereafter in effect in any jurisdiction affecting
any of such terms or the rights of the Agent, the LC Banks or the Lenders with
respect thereto.  The obligations of the Guarantor under this Guaranty are
independent of the Obligations, and a separate action or actions may be
brought and prosecuted against the Guarantor to enforce this Guaranty,
irrespective of whether any action is brought against the Borrower or whether
the Borrower is joined in any such action or actions.  The liability of the
Guarantor under this Guaranty shall be absolute, unconditional and irrevocable
irrespective of:

             (i)     any lack of validity or enforceability of the Credit
        Agreement, the Notes, any other Loan Document, any Advance, or any
        other agreement or instrument relating thereto;

             (ii)     any change in the time, manner or place of payment of, or
        in any other term of, all or any of the Obligations, or any other
        amendment or waiver of, or any consent to departure from, the Credit
        Agreement, the Notes or any other Loan Document, including, without
        limitation, any increase in the Obligations resulting from the
        extension of additional credit to the Borrower or otherwise and any
        extension of the Termination Date;

             (iii)     any manner of application of collateral, or proceeds
        thereof, to all or any of the Obligations, or any manner of sale or
        other disposition of, any release or impairment of, or any failure to
        perfect, any lien on or security interest in any collateral for all or
        any of the Obligations or any other assets of the Borrower or any of
        its Subsidiaries, or any release or discharge of any Person liable for
        any or all of the Obligations;

             (iv)     any change, restructuring or termination of the corporate
        structure or existence of the Borrower or any of its Subsidiaries or
        any bankruptcy, insolvency, liquidation or similar proceeding
        instituted by or against the Borrower or any of its Subsidiaries; or

             (v)     any other circumstance that might otherwise constitute a
        defense available to, or a discharge of, the Borrower or a guarantor.

As against the Guarantor, this Guaranty shall continue to be effective or be
reinstated, as the case may be, if at any time any payment of any of the
Obligations is rescinded or must otherwise be returned by the Agent, any LC
Bank

                                      xiv
<PAGE>
 
or any Lender upon the insolvency, bankruptcy or reorganization of the Borrower
or otherwise, all as though such payment had not been made.

     SECTION 4.  WAIVER.  The Guarantor hereby waives promptness, diligence,
presentment, protest, notice of protest, notice of dishonor, notice of
acceptance and any other notice with respect to any of the Obligations and
this Guaranty and any requirement that the Agent, any LC Bank or any Lender
protect, secure, perfect or insure any security interest or lien on any
property subject thereto or exhaust any right or take any action against the
Borrower or any other person or entity or any collateral.

     SECTION 5.  WAIVER OF RIGHTS OF SUBROGATION.  The Guarantor hereby
expressly and irrevocably waives with respect to the Borrower and its
successors and assigns and any other Person, any and all rights at law or in
equity, by agreement or otherwise, to subrogation, reimbursement, exoneration,
contribution, setoff, share in any collateral or any other rights that could
accrue to a surety against a principal, to a guarantor against a maker or
obligor, to an accommodation party against the party accommodated, or to a
holder or transferee against a maker, and that the Guarantor may have or
hereafter acquire against the Borrower, any of its Affiliates, or any other
Person in connection with or as a result of the Guarantor's execution,
delivery or performance hereunder.  In furtherance of the foregoing, the
Guarantor agrees that any payment by the Guarantor to the Agent, the LC Banks
or the Lenders pursuant to this Guaranty shall be deemed a contribution to the
capital of the Borrower, and no such payment shall constitute the Guarantor a
creditor of the Borrower.  The Guarantor hereby acknowledges and agrees that
the foregoing waivers are intended to benefit the Borrower, the Agent, the LC
Banks and the Lenders and shall not limit or otherwise affect the Guarantor's
liability hereunder or the enforceability hereof.  If, notwithstanding the
foregoing, any amount shall be paid to the Guarantor on account of such
subrogation rights at any time when all of the Obligations shall not have been
paid in full, such amount shall be held by the Guarantor in trust for the
Agent, the LC Banks and the Lenders, segregated from other funds of the
Guarantor, and shall, forthwith upon receipt by the Guarantor, be turned over
to the Agent in the exact form received by the Guarantor (duly endorsed by the
Guarantor to the Agent), to be applied against the Obligations, whether
matured or unmatured, in such order as the Agent may determine.

     SECTION 6.  REPRESENTATIONS AND WARRANTIES.  The Guarantor hereby
represents and warrants as follows:

     (a)     CORPORATE EXISTENCE AND POWER.  It is a corporation duly
incorporated, validly existing and in good standing under the laws of the State
of

                                       xv
<PAGE>
 
Illinois, is duly qualified to do business as a foreign corporation in, and is
in good standing under the laws of, each state in which the ownership of its
properties or the conduct of its business makes such qualification necessary,
except where the failure to be so qualified would not have a material adverse
effect on its business, assets, revenues, financial condition, results of
operations, operations or prospects or its ability to perform its obligations
under this Guaranty, and has all corporate powers and all governmental
licenses, authorizations, consents and approvals required to own or lease its
property and to carry on its business as now conducted.

     (b)     CORPORATE AUTHORIZATION.  The execution, delivery and performance
by it of this Guaranty have been duly authorized by all necessary corporate
action on its part and do not, and will not, require the consent or approval
of its shareholders, or any trustee or holder of any Debt or other obligation
of the Guarantor.

     (c)     NO VIOLATION, ETC.  The execution and delivery by the Guarantor
of this Guaranty, and the performance by the Guarantor of its obligations
hereunder, (i) are within the Guarantor's corporate powers, (ii) have been
duly authorized by all necessary corporate action and (iii) do not and will
not (A) violate any provision of the charter or by-laws of the Guarantor or of
law, (B) violate any legal restriction binding on or affecting the Guarantor,
(C) result in a breach of, or constitute a default under, any indenture or
loan or credit agreement or any other agreement, lease or instrument to which
the Guarantor is a party or by which it or its properties may be bound or
affected, or (D) result in or require the creation of any lien or security
interest upon or with respect to any of its properties.

     (d)     GOVERNMENTAL ACTIONS.  No authorization or approval or other
action by, and no notice to or filing with, any governmental authority or
regulatory body is required for the due execution, delivery and performance by
the Guarantor of this Guaranty.

     (e)     EXECUTION AND DELIVERY.  This Guaranty has been duly executed and
delivered by the Guarantor, and is the legal, valid and binding obligation of
the Guarantor enforceable against it in accordance with its terms, subject,
however, to the application by a court of general principles of equity and to
the effect of any applicable bankruptcy, insolvency, reorganization,
moratorium or similar laws affecting creditors' rights generally.

     (f)     LITIGATION.  There is no pending or threatened action or
proceeding (including, without limitation, any proceeding relating to, or
arising out of, any

                                      xvi
<PAGE>
 
Environmental Laws) affecting it or any of its Subsidiaries before any court,
governmental agency or arbitrator, that may have a material adverse effect on
the business, assets, revenues, financial condition, results of operations,
operations or prospects of the Guarantor or the Guarantor and its Subsidiaries,
taken as a whole, or on the Guarantor's ability to perform its obligations
under this Guaranty, or that questions the validity or enforceability of this
Guaranty or any other Loan Document against the Guarantor or the Borrower.

     (g)     FINANCIAL STATEMENTS; MATERIAL ADVERSE CHANGE.  The consolidated
balance sheet of the Guarantor and its Consolidated Subsidiaries as at
December 31, 1995, and the consolidated balance sheet of the Guarantor and its
Consolidated Subsidiaries as at June 30, 1996 and the related consolidated
statements of income, retained earnings and cash flows for the six-month
period then ended, together with the report thereon of Arthur Andersen LLP
included in the Guarantor's Quarterly Report on Form 10-Q for the quarterly
period ended June 30, 1996, copies of each of which have been furnished to
each Lender, fairly present (subject, in the case of such balance sheet and
statements of income, retained earnings and cash flows for the six months
ended June 30, 1996, to year-end adjustments) the financial condition of the
Guarantor and its Consolidated Subsidiaries as at such dates and the results
of operations of the Guarantor and its Consolidated Subsidiaries for the
periods ended on such dates, all in accordance with GAAP consistently applied
(except for such changes in accounting methods described in such report of
Arthur Andersen LLP).  Since December 31, 1995, there has been no material
adverse change in the business, assets, revenues, financial condition, results
of operations, operations or prospects of the Guarantor and its Subsidiaries,
taken as a whole, or the Borrower and its Subsidiaries, taken as a whole
(other than operating losses resulting from start-up operations of
Subsidiaries of the Borrower), or in the Guarantor's ability to perform any of
its obligations hereunder.

     (h)     ERISA.  During the preceding twelve-consecutive-month period, no
steps have been taken to terminate any Pension Plan, and no contribution
failure has occurred with respect to any Pension Plan sufficient to give rise
to a Lien under Section 302(f) of ERISA.  No condition exists or event or
transaction has occurred with respect to any Pension Plan which could result
in the incurrence by the Guarantor or any of its Subsidiaries of any material
liability, fine, or penalty.  The Guarantor has no contingent liability with
respect to any post-retirement benefit under a Welfare Plan, other than
liability for continuation coverage described in Part 6 of Title I of ERISA.

     (i)     TAXES.  The Guarantor and each of its Subsidiaries have filed all
tax returns (federal, state and local) required to be filed and paid all taxes
shown

                                      xvii
<PAGE>
 
thereon to be due, including interest and penalties, or provided adequate
reserves for payment thereof other than such taxes that the Guarantor or such
Subsidiary is contesting in good faith by appropriate legal proceedings and in
respect of which the Guarantor or such Subsidiary, as the case may be, has
established adequate reserves in conformity with GAAP.

     (j)     VIOLATION OF LAW.  Neither the Guarantor nor any of its
Subsidiaries is in violation of any law or governmental regulation or court
decree or order which may result in a material adverse effect on the business,
assets, revenues, financial condition, results of operations, operations or
prospects of the Guarantor and its Subsidiaries, taken as a whole, or the
Borrower and its Subsidiaries, taken as a whole, or on the Guarantor's ability
to perform any of its obligations hereunder.

     (k)     INVESTMENT COMPANY.  The Guarantor is not an "investment company"
or a company "controlled" by an "investment company" within the meaning of the
Investment Company Act of 1940, as amended, or an "investment advisor" within
the meaning of the Investment Advisers Act of 1940, as amended.

     (l)     HOLDING COMPANY.  The Guarantor is a "holding company" within the
meaning of the Public Utility Holding Company Act of 1935, as amended, but the
Guarantor and its Subsidiaries are exempt from the provisions of that Act,
except Section 9(a)(2) thereof, by virtue of an order issued by the Securities
and Exchange Commission on July 22, 1994.  Such exemption is in full force and
effect and the Guarantor is not aware of any existing or proposed proceedings
contemplating the revocation or modification of such exemption.

     (m)     INFORMATION.  All factual information heretofore or
contemporaneously furnished by or on behalf of the Guarantor in writing to the
Agent or any Lender for purposes of or in connection with this Guaranty or any
transaction contemplated hereby is, and all other such factual information
hereafter furnished by or on behalf of the Guarantor to the Agent, any LC Bank
or any Lender will be, true and accurate in every material respect on the date
as of which such information is dated or certified, and not incomplete by
omitting to state any material fact necessary to make such information not
misleading.

     (n)     NO CONDITIONS PRECEDENT.  There are no conditions precedent to
the effectiveness of this Guaranty that have not been satisfied or waived.

     (o)     RELIANCE.  The Guarantor has, independently and without reliance
upon the Borrower and based on such documents and information as it has

                                     xviii
<PAGE>
 
deemed appropriate, made its own credit analysis and decision to enter into
this Guaranty.

     SECTION 7.  AFFIRMATIVE COVENANTS.  The Guarantor covenants and agrees
that, so long as any part of the Obligations shall remain unpaid or any Lender
shall have any Commitment, the Guarantor will:

     (a)     REPORTING REQUIREMENTS.  Furnish to each Lender:

             (i)     as soon as available and in any event within 60 days after
        the end of each of the first three quarters of each fiscal year of the
        Guarantor, a consolidated balance sheet of the Guarantor and its
        Consolidated Subsidiaries as of the end of such quarter and
        consolidated statements of income, retained earnings and cash flows of
        the Guarantor and its Consolidated Subsidiaries for the period
        commencing at the end of the previous fiscal year and ending with the
        end of such quarter, all in reasonable detail and duly certified
        (subject to year-end audit adjustments) by the chief financial officer
        or the Treasurer of the Guarantor as having been prepared in accordance
        with GAAP consistently applied, except for (A) the absence of notes
        thereto and (B) changes in accounting principles required by GAAP;

             (ii)     as soon as available and in any event within 90 days
        after the end of each fiscal year of the Guarantor and its Consolidated
        Subsidiaries, a copy of the annual report for such year for the
        Guarantor and its Consolidated Subsidiaries, containing a consolidated
        balance sheet of the Guarantor and its Consolidated Subsidiaries as at
        the end of such fiscal year and consolidated statements of income,
        retained earnings and cash flows of the Guarantor and its Consolidated
        Subsidiaries for such fiscal year, certified in a manner acceptable to
        the Agent by Arthur Andersen LLP or another nationally-recognized
        independent public accounting firm selected by the Guarantor and
        acceptable to the Agent;

             (iii)     concurrently with the financial statements for each
        quarterly accounting period and for each fiscal year of the Guarantor
        furnished pursuant to paragraphs (i) and (ii), above, (A) a certificate
        of the chief financial officer, any vice president responsible for
        financial or accounting matters, or the treasurer of the Guarantor
        stating that (1) the Guarantor has performed and observed all of, and
        the Guarantor is not in default in the performance or observance of any
        of, the terms, covenants, agreements and conditions of this Guaranty
        or, if the Guarantor shall be in default, specifying all such defaults
        and the nature thereof, of which the signer of

                                      xix
<PAGE>
 
        such certificate may have knowledge, and (2) the signer has obtained no
        knowledge of any Unmatured Default or Event of Default except as
        specified in such certificate, and (B) an analysis prepared and
        certified by the chief financial officer, any vice president
        responsible for financial or accounting matters, or the Treasurer of
        the Guarantor of the covenants contained in Sections 7(i) and (j),
        containing all information necessary for determining compliance by the
        Guarantor with such covenants;

             (iv)     as soon as available and in any event within 90 days
        after the end of each fiscal year of the Guarantor and concurrently
        with the financial statements furnished pursuant to paragraph (ii),
        above, a written statement of the independent public accountants that
        certified such financial statements stating that, in making the
        examination necessary for their certification of such financial
        statements, they have obtained no knowledge of any default by the
        Guarantor in the observance of any of the covenants contained in
        Section 7(i) or (j) or, if such accountants shall have obtained
        knowledge of any such default, specifying all such defaults and the
        nature thereof, it being understood that they shall not be liable
        directly or indirectly for any failure to obtain knowledge of any
        default;

             (v)     as soon as possible and in any event within ten days after
        the commencement of litigation against the Guarantor, the Borrower, or
        any of their respective Subsidiaries that could reasonably be expected
        to have a material adverse effect on the business, assets, revenues,
        financial condition, results of operations, operations or prospects of
        the Guarantor and its Subsidiaries, taken as a whole, or that questions
        the validity or enforceability of any of the Loan Documents again'st
        the Guarantor or the Borrower, notice of such litigation describing in
        reasonable detail the facts and circumstances concerning such
        litigation and the Guarantor's, the Borrower's or such Subsidiary's, as
        the case may be, proposed actions in connection therewith;

             (vi)     promptly after the sending or filing thereof, copies of
        all reports which the Guarantor sends to any of its security holders,
        and copies of all reports and registration statements (other than
        registration statements relating to (A) the offering of debt or
        preferred/preference stock equity securities and (B) employee benefit
        plans) which the Guarantor or any of its Subsidiaries files with the
        Securities and Exchange Commission or any national securities exchange;

             (vii)     promptly after the occurrence of the institution of any
        steps by the Guarantor or any other Person to terminate any Pension
        Plan, or the

                                       xx
<PAGE>
 
        failure to make a required contribution to any Pension Plan if such
        failure is sufficient to give rise to a Lien under Section 302(f) of
        ERISA, or the taking of any action with respect to a Pension Plan which
        could result in the requirement that the Guarantor or any of its
        Subsidiaries furnish a bond or other security to the PBGC or such
        Pension Plan, or the occurrence of any event with respect to any
        Pension Plan which could result in the incurrence by the Guarantor or
        any of its Subsidiaries of any material liability, fine, or penalty, or
        any material increase in the contingent liability of the Guarantor or
        any of its Subsidiaries with respect to any post-retirement Welfare
        Plan benefit, notice of such event and the action the Guarantor
        proposes to take with respect thereto;

             (viii)     as soon as possible and in any event within ten days
        after the Guarantor knows or should have reason to know of the
        occurrence of each Unmatured Default or Event of Default continuing on
        the date of such statement, a statement of the chief financial officer,
        any vice president responsible for financial or accounting matters, or
        the Treasurer of the Guarantor setting forth details of such Unmatured
        Default or Event of Default and the action that the Guarantor or the
        Borrower has taken and proposes to take with respect thereto; and

             (ix)     such other information (other than proprietary customer
        information) respecting the business, assets, revenues, financial
        condition, results of operations, operations or prospects of the
        Guarantor, the Borrower, or any of their respective Subsidiaries as the
        Agent or any Lender may from time to time reasonably request.

     (b)     PRESERVATION OF CORPORATE EXISTENCE, ETC.  Preserve and maintain,
and cause each of its Subsidiaries to preserve and maintain, its legal
existence in the jurisdiction of its organization and qualify and remain
qualified as a foreign organization in each jurisdiction in which such
qualification is reasonably necessary in view of its business and operations
or the ownership of its properties, and preserve, renew and keep in full force
and effect the rights, privileges and franchises necessary or desirable in the
normal conduct of its business, except to the extent that the Guarantor's
chief financial officer certifies to the Lenders that the loss of any such
right, privilege or franchise, both individually and together with all other
rights, privileges and franchises lost since the Effective Date, would not
have a Material Adverse Effect.

     (c)     COMPLIANCE WITH LAWS, ETC.  Comply, and cause each of its
Subsidiaries to comply, in all material respects with all Applicable Laws,
such compliance to include compliance with ERISA and Environmental Laws.

                                      xxi
<PAGE>
 
     (d)     MAINTENANCE OF INSURANCE, ETC.  Maintain, and cause each of its
Subsidiaries to maintain, such insurance as may be required by law and such
other insurance, to the extent and against such hazards and liabilities, as is
customarily maintained by companies similarly situated.

     (e)     INSPECTION RIGHTS.  At any reasonable time and from time to time
as the Agent or any Lender may reasonably request, permit the Agent, each
Lender or any agents or representatives thereof to examine and make copies of
and abstracts from the records and books of account of, and visit the
properties of, the Guarantor and any of its Subsidiaries (except in the case
of Commonwealth, as may be restricted by law), and to discuss the affairs,
finances and accounts of the Guarantor and any of its Subsidiaries with any of
their respective officers or directors.

     (f)     MAINTAINING OF BOOKS.  Maintain, and cause each of its
Subsidiaries to maintain, complete and accurate books of record and account in
which entries shall be made of all financial transactions and the assets and
business of the Guarantor and each of its Subsidiaries in accordance with
GAAP.

     (g)     MAINTENANCE OF PROPERTIES.  Cause all properties used or useful
in the conduct of the business of the Guarantor or any of its Subsidiaries to
be maintained and kept in reasonable condition, repair and working order, and
cause to be made all necessary repairs, renewals, replacements, betterments
and improvements thereof, all as in the judgment of the Guarantor may be
necessary so that the business carried on in connection therewith may be
properly and advantageously conducted at all times; provided, however, that
neither the Guarantor nor any such Subsidiary shall be prevented from
discontinuing the operation and maintenance of any such properties if the
chief financial officer of the Guarantor certifies that such discontinuance is
desirable in the conduct of the Guarantor's or such Subsidiary's business and
such discontinuance, individually or with all such other discontinuances since
the date hereof, would not have a material adverse effect on the business,
assets, revenues, financial condition, results of operations, operations or
prospects of the Guarantor and its Subsidiaries, taken as a whole.

     (h)     TAXES AND LIABILITIES.  Pay, and cause each of its Subsidiaries
to pay, when due all taxes, assessments, governmental charges and other
liabilities imposed upon it or its property, except to the extent contested in
good faith and by appropriate proceedings and in respect of which adequate
reserves for the payment thereof have been set aside by the Guarantor or such
Subsidiary, as the case may be, in accordance with GAAP.

                                      xxii
<PAGE>
 
     (i)     MAINTENANCE OF MINIMUM TANGIBLE NET WORTH.  Maintain at all times
an excess of (i) the Tangible Net Worth of the Guarantor and its Consolidated
Subsidiaries over (ii) the Tangible Net Worth of Commonwealth and its
Consolidated Subsidiaries, of at least $10,000,000.

     (j)     CONSOLIDATED LEVERAGE RATIO.  Maintain, on the last day of each
fiscal quarter, a ratio of (i) Consolidated Debt to (ii) Consolidated
Capitalization of not greater than 0.65 to 1.

     (k)     ERISA.  Maintain, and cause each of its Consolidated Subsidiaries
to maintain, each of its defined benefit plans in substantial compliance with
all applicable requirements of ERISA and of the Code and with all applicable
rulings and regulations issued under the provisions of ERISA and the Code.

     (l)     OWNERSHIP OF SUBSIDIARIES.  Maintain direct ownership of 100% of
the capital stock of the Borrower and at least 80% of the voting capital stock
of Commonwealth.

     SECTION 8.  NEGATIVE COVENANTS.  The Guarantor covenants and agrees that,
so long as any part of the Obligations shall remain unpaid or any Lender shall
have any Commitment, the Guarantor will not:

     (a)     LIENS, ETC.  Create or suffer to exist, or permit any of its
Subsidiaries to create or suffer to exist, any lien, security interest, or
other charge or encumbrance, or any other type of preferential arrangement,
upon or with respect to any of its properties (including, without limitation,
the capital stock of or any other equity interest in any of its Subsidiaries),
whether now owned or hereafter acquired, or assign, or permit any of its
Subsidiaries to assign, any right to receive income, in each case to secure or
provide for the payment of any Debt of any Person (any of the foregoing being
referred to herein as a "Lien"), other than (i) Liens imposed by law, such as
carriers', warehousemen's and mechanics' Liens and other similar Liens arising
in the ordinary course of business; (ii) Liens arising under the Indenture;
(iii) "permitted liens", as such term is defined in the Indenture; (iv) other
Liens permitted by Section 6.02(e) of the Credit Agreement; (v) Liens on the
capital stock of or any other equity interest in any of the Guarantor's
Subsidiaries or any such Subsidiary's assets to secure the payment and
performance of Debt obligations in connection with any project financing for
such Subsidiary (provided that the obligee of such obligations shall have no
recourse to the Guarantor to satisfy such obligations, other than pursuant to
any such Liens on the Guarantor's equity interests in its Subsidiaries), (vi)
Liens created in connection with the acquisition by Subsidiaries of assets and
the continuation of such Liens in connection with any refinancing of the Debt
secured

                                     xxiii
<PAGE>
 
by such Liens, provided such Liens are limited to the assets so acquired; and
(vii) Liens on the assets and/or rights to receive income of any Person that
exist at the time such Person becomes a Subsidiary and the continuation of such
Liens in connection with any refinancing or restructuring of the obligations
secured by such Liens;  provided, however, that, notwithstanding the foregoing,
if both before and after giving effect thereto no Unmatured Default or Event of
Default shall have occurred and be continuing, Commonwealth may sell, pledge or
otherwise dispose of its accounts receivable.

     (b)     MERGERS, ETC.  Merge or consolidate with or into any Person, or
convey, transfer, lease or otherwise dispose of (whether in one transaction or
in a series of transactions, and whether in a sale/leaseback transaction or
otherwise) more than 10% of its assets (whether now owned or hereafter
acquired), unless, in the case of a merger, immediately after giving effect
thereto, (i) no event shall occur and be continuing that constitutes an
Unmatured Default or an Event of Default, (ii) the Guarantor is the surviving
corporation, (iii) the Guarantor's Tangible Net Worth shall be equal to or
greater than its Tangible Net Worth immediately prior to such merger and (iv)
the Guarantor shall not be liable with respect to any Debt or allow its
property to be subject to any Lien which it could not become liable with
respect to or allow its property to become subject to under this Guaranty on
the date of such transaction.

     (c)     DEBT.  Create, incur, assume or suffer to exist any Debt, other
than (without duplication) (i) Debt to the Borrower in an amount not to exceed
$25,000,000 in the aggregate at any one time outstanding, (ii) Debt hereunder,
(iii) unsecured Contingent Obligations (other than in respect of this
Guaranty) in an aggregate amount at any one time outstanding not to exceed the
excess of (A) $300,000,000 over (B) the amount of Contingent Obligations
incurred by the Borrower and its Subsidiaries pursuant to Section 6.02(b)(ii)
of the Credit Agreement, and (iv) other unsecured Debt; provided, however,
that, notwithstanding the foregoing, the aggregate amount of Debt of the
Guarantor, the Borrower and Subsidiaries of the Borrower at any one time
outstanding shall not exceed $750,000,000.

     (d)     GUARANTOR AND SUBSIDIARIES' STOCK.  Permit any of its
Subsidiaries to purchase or otherwise acquire any shares of capital stock of
the Guarantor; or take any action, or permit any such Subsidiary to take any
action, that would result in a material decrease in the percentage of the
outstanding shares of capital stock of any "Significant Subsidiary" of the
Guarantor (within the meaning of Rule 1-02 of the Regulation S-X of the
Securities and Exchange Commission) owned by the Guarantor and its other
Subsidiaries; provided, however, that the Guarantor or Commonwealth may take
any such action with respect to the capital

                                      xxiv
<PAGE>
 
stock of Commonwealth, provided that, after giving effect to any such action,
the Guarantor is in compliance with Section 7(l) hereof.

     (e)     OTHER AGREEMENTS.  Enter into any agreement containing any
provision that would be violated or breached by the performance of its
obligations hereunder or under any instrument or document delivered or to be
delivered by the Guarantor hereunder or in connection herewith.

     (f)     TRANSACTIONS WITH AFFILIATES.  Enter into, or permit any of its
Subsidiaries to enter into, any transaction with an Affiliate of the
Guarantor, unless such transaction is on terms no less favorable to the
Guarantor or such Subsidiary, as the case may be, than if the transaction had
been negotiated in good faith on an arm's length basis with a Person that was
not an Affiliate of the Guarantor; provided, however, that the foregoing
restrictions shall not apply to any transaction between the Guarantor and any
of its Subsidiaries, between the Guarantor and Commonwealth, or between
Commonwealth and any of the Guarantor's other Subsidiaries.

     (g)     DISTRIBUTIONS.  Upon the occurrence and during the continuance of
an Event of Default, declare or pay, directly or indirectly, any dividend,
payment or other distribution of assets, properties, cash, rights, obligations
or securities on account of any share of any class of capital stock of the
Guarantor, or purchase, redeem, retire, or otherwise acquire for value, or
permit any of its Subsidiaries to purchase, redeem, retire, or otherwise
acquire for value, any shares of any class of capital stock of the Guarantor
or any warrants, rights, or options to acquire any such shares, now or
hereafter outstanding, or make any distribution of assets to any of its
shareholders; provided, however, that, notwithstanding the foregoing, the
Guarantor may, to the extent that it is legally required to do so, pay any
such dividend, payment or other distribution after the Guarantor has declared
such dividend, payment or other distribution.

     SECTION 9.  AMENDMENTS, ETC.  No amendment or waiver of any provision of
this Guaranty, and no consent to any departure by the Guarantor herefrom,
shall in any event be effective unless the same shall be in writing and signed
by the Agent and the Majority Lenders, and then such waiver or consent shall
be effective only in the specific instance and for the specific purpose for
which given, provided, however, that no amendment, waiver or consent shall,
unless in writing and signed by all of the Lenders, (i) limit the liability
of, or release, the Guarantor hereunder, (ii) postpone any date fixed for
payment hereunder, or (iii) change the number of Lenders required to take any
action hereunder.

                                      xxv
<PAGE>
 
     SECTION 10.  ADDRESSES FOR NOTICES.  All notices and other communications
provided for hereunder shall be in writing (including telecopier, telegraphic
or cable communication) and mailed, telecopied, telegraphed, cabled or
delivered to it, (i) if to the Guarantor, at its address at P.O. Box A-3005,
10 South Dearborn Street, 38th Floor, Chicago, Illinois 60690-3005, Attention:
Treasurer, Telecopy: (312) 394-4082, and (ii) if to the Agent, any LC Bank or
any Lender, at its address specified in the Credit Agreement or, as to any
party, at such other address as shall be designated by such party in a written
notice to each other party.  All such notices and other communications shall,
when mailed, telecopied, telegraphed or cabled, be effective when deposited in
the mails, telecopied, delivered to the telegraph company or delivered to the
cable company, respectively.

     SECTION 11.  NO WAIVER; REMEDIES.  No failure on the part of the Agent,
any LC Bank or any Lender to exercise, and no delay in exercising, any right
hereunder shall operate as a waiver thereof; nor shall any single or partial
exercise of any right hereunder preclude any other or further exercise thereof
or the exercise of any other right.  The remedies herein provided are
cumulative and not exclusive of any remedies provided by law.

     SECTION 12.  RIGHT OF SET-OFF.  Upon the occurrence and during the
continuance of any Event of Default, each Lender and LC Bank is hereby
authorized at any time and from time to time, to the fullest extent permitted
by law, to set off and apply any and all deposits of the Guarantor (general or
special, time or demand, provisional or final).  Each Lender and LC Bank
agrees promptly to notify the Agent and the Guarantor after any such set-off
and application made by such Lender, provided that the failure to give such
notice shall not affect the validity of such set-off and application.  The
rights of each Lender and LC Bank under this Section are in addition to other
rights and remedies (including, without limitation, other rights of set-off)
that such Lender or LC Bank may have.

     SECTION 13.  CONTINUING GUARANTY; ASSIGNMENTS UNDER CREDIT AGREEMENT.
This Guaranty is a continuing guaranty and shall (i) subject to the last
sentence of Section 3, remain in full force and effect until the later to
occur of (A) the payment in full of the Obligations and all other amounts
payable under this Guaranty and (B) the expiration or termination of the
Commitments, (ii) be binding upon the Guarantor, its successors and assigns
(provided, that the Guarantor may not assign any of its rights or obligations
hereunder without the prior written consent of the Lenders), and (iii) inure
to the benefit of, and be enforceable by, the Agent, the LC Banks, the Lenders
and their respective successors, transferees and assigns.  Without limiting
the generality of the foregoing clause (iii), any Lender may assign or
otherwise transfer all or any

                                      xxvi
<PAGE>
 
portion of its rights and obligations under the Credit Agreement (including,
without limitation, all or any portion of its Commitment, the Advances owing to
it and any Note held by it) to any other person or entity pursuant to Section
9.07 thereof, and such other person or entity shall thereupon become vested
with all the benefits in respect thereof granted to such Lender herein or
otherwise, subject, however, to the provisions of Article VIII (concerning the
Agent) of the Credit Agreement.

     SECTION 14.  GOVERNING LAW.  THIS GUARANTY SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

     SECTION 15.  CONSENT TO JURISDICTION; WAIVER OF JURY TRIAL.   (a)  The
Guarantor hereby irrevocably (i) submits to the non-exclusive jurisdiction of
any New York State or Federal court sitting in New York City and any appellate
court from any thereof in any action or proceeding arising out of or relating
to this Guaranty or any other Loan Document and (ii) agrees that all claims in
respect of such action or proceeding may be heard and determined in such New
York State court or in such Federal court.  The Guarantor hereby irrevocably
waives the defense of an inconvenient forum to the maintenance of such action
or proceeding and any objection to venue in connection therewith.  The
Guarantor also irrevocably consents to the service of any and all process in
any such action or proceeding by the mailing by certified mail of copies of
such process to the Guarantor at its address specified in Section 10.  The
Guarantor agrees that a final judgment in any such action or proceeding shall
be conclusive and may be enforced in other jurisdictions by suit on the
judgment or in any other manner provided by law.

     (b)     THE GUARANTOR HEREBY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY
ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS
GUARANTY, ANY OTHER LOAN DOCUMENT, OR ANY OTHER INSTRUMENT OR DOCUMENT
DELIVERED HEREUNDER OR THEREUNDER.

     SECTION 16.  EXECUTION IN COUNTERPARTS.   This Guaranty may be executed
in any number of counterparts and by different parties hereto in separate
counterparts, each of which counterparts when so executed shall be deemed to
be an original and all of which taken together shall constitute one and the
same agreement.

     SECTION 17.  SEVERABILITY.  Any provision of this Guaranty or any other
Loan Document that is prohibited, unenforceable or invalid in any jurisdiction

                                     xxvii
<PAGE>
 
shall, as to such jurisdiction, be ineffective to the extent of such
prohibition, unenforceability or invalidity without invalidating the remaining
provisions hereof or thereof or affecting the validity, enforceability or
legality of such provision in any other jurisdiction.

     SECTION 18.  HEADINGS.  Article and Section headings used herein are for
convenience of reference only, are not part of this Guaranty and are not to
affect the construction of, or to be taken into consideration in interpreting,
this Guaranty.

     SECTION 19.  ENTIRE AGREEMENT.  This Guaranty constitutes the entire
agreement and understanding among the Guarantor, the Lenders, the LC Banks and
the Agent relative to the subject matter hereof.  Any previous agreement by or
among such parties with respect to the subject matter hereof is superseded by
this Guaranty.  Nothing in this Guaranty, expressed or implied, is intended to
confer upon any party other than the Lenders, the LC Banks and the Agent any
rights, remedies, obligations, or liabilities under or by reason of this
Guaranty.







                                     xxviii
<PAGE>
 
     IN WITNESS WHEREOF, the Guarantor has caused this Guaranty to be duly
executed and delivered by its officer thereunto duly authorized as of the date
first above written.

                         UNICOM CORPORATION


                         By
                            -------------------------------
                            Name:
                            Title:






                         SIGNATURE PAGE TO THE GUARANTY
                                      xxix
<PAGE>
 
     EXHIBIT F


                           FORM OF OPINION OF COUNSEL
                        FOR THE BORROWER AND THE PARENT


                                       [Date of Initial Extension of Credit]


To each of the Lenders party to the Credit
Agreement hereinafter referred to and to
Citibank, N.A., as Agent


                          RE:  UNICOM ENTERPRISES INC.

Ladies and Gentlemen:

     This opinion is furnished to you pursuant to Section 4.01(x) of the
Amended and Restated Credit Agreement, dated as of November 15, 1996 (the
"CREDIT AGREEMENT"), among Unicom Enterprises Inc., an Illinois corporation
(the "BORROWER"), the Lenders named therein and from time to time party
thereto and Citibank, N.A., as Agent for said Lenders.  Unless otherwise
defined herein, terms defined in the Credit Agreement are used herein as
therein defined.

     We have acted as counsel to the Borrower and to Unicom Corporation, an
Illinois corporation (the "PARENT"; together with the Borrower, the "LOAN
PARTIES"), in connection with the preparation, execution and delivery of the
Credit Agreement and the other Loan Documents to be delivered thereunder.

     In that capacity, we have examined:

     (1)     the Credit Agreement;

     (2)     the Notes executed and delivered on the date hereof;

     (3)     the Guaranty;

     (4)     the form of the LC Bank Agreement attached as Exhibit D to the
Credit Agreement;



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                                      xxx
<PAGE>
 
     (5)     the other documents furnished by the Borrower and the Parent
pursuant to Section 4.01 of the Credit Agreement;

     (6)     the Articles of Incorporation of the Borrower and all amendments
thereto (the "BORROWER CHARTER");

     (7)     the by-laws of the Borrower and all amendments thereto (the
"BORROWER BY-LAWS");

     (8)     a certificate of the Secretary of State of the State of Illinois,
dated November     , 1996, attesting to the continued corporate existence and
good standing of the Borrower in that State;

     (9)     the Articles of Incorporation of the Parent and all amendments
thereto (the "PARENT CHARTER");

     (10)     the by-laws of the Parent and all amendments thereto (the
"PARENT BY-LAWS"); and

     (11)     a certificate of the Secretary of State of the State of
Illinois, dated November ___, 1996, attesting to the continued corporate
existence and good standing of the Parent in that State.

     We are familiar with the corporate proceedings taken by the Borrower and
the Parent in connection with the foregoing agreements and documents and the
transactions contemplated thereby.  We have relied, as to various questions of
fact material to the opinions expressed below, upon the representations made
by the Borrower in the Credit Agreement and by the Parent in the Guaranty and
upon certificates delivered by or on behalf of each of them on the date
hereof.  We have also examined originals, or copies of originals certified to
our satisfaction, of such agreements, documents, certificates and other
statements of government officials and other instruments, have examined such
questions of law and have satisfied ourselves as to such matters of fact as we
have considered relevant and necessary as a basis for the opinions hereinafter
expressed.  We have assumed the authenticity of all documents submitted to us
as originals, the genuineness of all signatures, the legal capacity of all
natural persons and the conformity with the original documents of any copies
thereof submitted to us for our examination.

     Based upon, and subject to, the foregoing, it is our opinion that:

     1.     Each of the Loan Parties is a corporation duly organized, validly
existing and in good standing under the laws of the State of Illinois.  Each of
the


                         SIGNATURE PAGE TO THE GUARANTY
                                      xxxi
<PAGE>
 
Loan Parties has full corporate power and authority to own and to hold
under lease its property and to conduct its business substantially as
currently being conducted by it.  The Borrower has full corporate power and
authority (a) to execute, deliver and perform its obligations under the Credit
Agreement and the Notes, and (a) to obtain Extensions of Credit as
contemplated by the Credit Agreement.  The Parent has full corporate power and
authority to execute, deliver and perform its obligations under the Guaranty.

     2.     The execution, delivery and performance by the Borrower of the
Credit Agreement, the Notes and the other Loan Documents to which it is, or is
to become, a party have been duly authorized by all necessary corporate
action, and do not and will not (A) breach, constitute a default under or
otherwise violate (i) the Borrower Charter or the Borrower By-laws, (ii) any
law, rule or regulation binding on the Borrower, (iii) to our knowledge, any
order, decree, writ or judgment to which the Borrower is a party or (iv) to our
knowledge, any indenture, any loan or credit agreement or any other agreement,
lease or instrument to which the Borrower is a party or by which it or its
properties are bound or (B) to our knowledge, result in or create any lien or
security interest on or in any of the Borrower's properties.

     3.     The execution, delivery and performance by the Parent of the
Guaranty have been duly authorized by all necessary corporate action, and do
not and will not (A) breach, constitute a default under or otherwise violate
(i) the Parent Charter or the Parent By-laws, (ii) any law, rule or regulation
binding on the Parent, (iii) to our knowledge, any order, decree, writ or
judgment to which the Parent is a party or (iv) to our knowledge, any
indenture, any loan or credit agreement or any other agreement, lease or
instrument to which the Parent is a party or by which it or its properties are
bound or (B) to our knowledge, result in or create any lien or security
interest on or in any of the Parent's properties.

     4.     To our knowledge, neither the Parent nor any of its Subsidiaries
is in default in the payment of (or in the performance of any material
obligation applicable to) any Debt or Contingent Obligation exceeding
$5,000,000, in the case of the Parent, the Borrower or Northwind, or any Debt
or Contingent Obligation exceeding $20,000,000, in the case of Commonwealth
Edison Company or any of its Subsidiaries, or in violation of any court decree
or order which could reasonably be expected to result in a material adverse
effect on the business or financial condition of the Borrower.

     5.     The Credit Agreement and the Notes have been duly executed and
delivered by the Borrower.  Each of the Credit Agreement and the Notes
constitutes, and each LC Bank Agreement, when duly completed, executed and


                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxii
<PAGE>
 
delivered by an authorized officer of the Borrower, will constitute, the
legal, valid and binding obligation of the Borrower, enforceable against the
Borrower in accordance with its respective terms, subject to bankruptcy,
insolvency, reorganization, moratorium, fraudulent conveyance and other
similar laws of general applicability relating to or affecting the
enforceability of creditors' rights generally, and except as the
enforceability thereof may be limited by general principles of equity
(regardless of whether enforceability is considered in a proceeding at law or
in equity).

     6.     The Guaranty has been duly executed and delivered by the Parent
and constitutes the legal, valid and binding obligation of the Parent,
enforceable against the Parent in accordance with its terms, subject to
bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance and
other similar laws of general applicability relating to or affecting the
enforceability of creditors' rights generally, and except as the
enforceability thereof may be limited by general principles of equity
(regardless of whether enforceability is considered in a proceeding at law or
in equity).

     7.     To our knowledge, except as disclosed in writing by the Parent or
the Borrower to the Lenders on or prior to the date hereof, there is no
pending or overtly threatened action or proceeding to which the Parent or any
of its Subsidiaries is a party before any court, governmental agency or
arbitrator which relates to the Credit Agreement, the Notes or the Guaranty
which could reasonably be expected to materially and adversely affect the
Parent's performance of its obligations under the Guaranty or the Borrower's
performance of its obligations under the Credit Agreement or the Notes.

     8.     No authorization or approval or other action by, and no notice to
or filing with, any governmental authority or regulatory body is or will be
required to be made or obtained by the Parent or any of its Subsidiaries in
connection with the execution, delivery and performance by the Borrower or the
Parent of any Loan Document to which it is, or is to become, a party.

     9.     Neither the Borrower nor the Parent is an "investment company" or
a company "controlled" by an "investment company" within the meaning of the
Investment Company Act of 1940, as amended, or an "investment advisor" within
the meaning of the Investment Advisors Act of 1940, as amended.

    10.     The Borrower is not a "public utility holding company" within the
meaning of the Public Utility Holding Company Act of 1935, as amended (the
"ACT").  The Parent is a "public utility holding company" within the meaning
of the Act, but the Parent and its Subsidiaries are exempt from the provisions
of the


                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxiii
<PAGE>
 
Act, except Section 9(a)(2) thereof, by virtue of an order dated July 22, 1994
issued by the Securities and Exchange Commission.  Such order is in full force
and effect and, to our knowledge, there are no pending or overtly threatened
proceedings contemplating the revocation or modification of such order.

     In rendering the opinions set forth in paragraph 5 above with respect to
the Credit Agreement and any LC Bank Agreement, we have assumed, with your
approval: the due authorization, execution and delivery of such agreements on
behalf of all parties thereto other than the Borrower; the legality, validity,
binding effect and enforceability of such agreements with respect to all such
other parties, except as enforceability may be limited by bankruptcy,
insolvency, reorganization, moratorium, fraudulent conveyance and other
similar laws of general  applicability relating to or affecting the
enforceability of creditors' rights generally, and except as the
enforceability thereof may be limited by general principles of equity
(regardless of whether enforceability is considered in a proceeding at law or
in equity); and such authorization, execution and delivery and the performance
of the Credit Agreement and any LC Bank Agreement by the Agent and the Lenders
will not violate any law, rule, regulation, permit or court order applicable
thereto or violate any agreement, document or instrument binding upon the
Agent or the Lenders.

     We express no opinion as to (i) the enforceability of the last sentence
of Section 2.13(a)  and the last sentence of Section 2.13(b) of the Credit
Agreement to the extent that such sentences state that non-manifest errors
contained in the certificates referred to therein are conclusive and binding,
(ii) the enforceability of the provisions contained in Section 9.10 of the
Credit Agreement, Section 15(a) of the Guaranty or Section 6.08 of the LC Bank
Agreement with respect  to the submission to the jurisdiction of the United
States District Court for the Southern District of New York, (iii) the
enforceability of the provisions contained in Section 9.08 of the Credit
Agreement, Section 15(b) of the Guaranty or Section 6.07 of the LC Bank
Agreement with respect to the waiver of jury trial or (iv) Sections 3.05(i),
(iv) and (vi) of the Credit Agreement and Sections 3(i) and (v) of the
Guaranty to the extent that such provisions constitute a waiver of illegality
as a defense to performance of contractual obligations or any other defense
which cannot, as a matter of law, be effectively waived or a waiver of rights
to seek protection under the Federal Bankruptcy Code or other similar law.

     Any opinion or statement herein which is expressed to be "to our
knowledge" or is otherwise qualified by words of like import means that the
lawyers in this firm who have had an involvement in negotiating the Loan
Documents and, in connection with the opinions set forth in paragraph 7 above,
such lawyers and the lawyers in this firm who currently supervise litigation
and

                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxiv
<PAGE>
 
regulatory matters handled by this firm for Commonwealth Edison Company,
have no current conscious awareness of any facts or information contrary to
such opinion or statement.  This opinion is limited to the federal laws of the
United States of America and the laws of the States of Illinois and New York.

     This opinion is being delivered solely for the benefit of the persons to
whom it is addressed; accordingly, except as set forth below, it may not be
relied upon by any other person or otherwise circulated or utilized for any
purpose without our prior written consent.  It may not be quoted or filed with
any governmental authority or other regulatory agency (except to the extent
required by law).  We assume no obligation to update or supplement the
opinions or statements expressed herein to reflect any facts or circumstances
which may hereafter come to our  attention with respect to such opinions or
statements, including any changes in applicable law which may hereafter occur.

     We are aware that King & Spalding will reply upon this opinion in
rendering their opinion furnished pursuant to Section 4.01(xi) of the Credit
Agreement and we hereby authorize such reliance.

                                        Very truly yours,



                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxv
<PAGE>
 
     November 15, 1996



To each of the Lenders parties to the
  Credit Agreement referred to below,
  and to Citibank, N.A., as Agent


     Re:  UNICOM ENTERPRISES INC.
Ladies and Gentlemen:

     This opinion is furnished to you pursuant to Section 4.01(xi) of the
Amended and Restated Credit Agreement dated as of November 15, 1996 (the
"CREDIT AGREEMENT") among Unicom Enterprises Inc. (the "BORROWER") the Banks
parties thereto and the other Lenders from time to time parties thereto and
Citibank, N.A., as Agent.  Unless otherwise defined herein, terms defined in
the Credit Agreement are used herein as therein defined.

     We have acted as special New York counsel to the Agent in connection with
the preparation, execution and delivery of the Credit Agreement.

          In that connection, we have examined the following documents:

             (a)     counterparts of the Credit Agreement, executed by each of
        the parties thereto,

             (b)     the Notes of the Borrower payable to the order of each
        Bank, executed by the Borrower,

             (c)     counterparts of the Guaranty, executed by the Parent, and

             (d)     the other documents furnished to the Agent pursuant to
        Section 4.01 of the Credit Agreement, including, without limitation,
        the opinion of counsel (the "OPINION") delivered pursuant to Section
        4.01(x) of the Credit Agreement.


                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxvi
<PAGE>
 
     In our examination of the documents referred to above, we have assumed
the authenticity of all such documents submitted to us as originals, the
genuineness of all signatures, the due authority of the parties executing such
documents and the conformity to the originals of all such documents submitted
to us as copies.   We have further assumed that you have evaluated, and are
satisfied with, the creditworthiness of the Borrower and the Parent and the
business and financial terms evidenced by the Credit Agreement and the other
Loan Documents.  We have relied, as to factual matters, on the documents we
have examined.

     To the extent that our opinions expressed below involve conclusions as to
matters governed by law other than the law of the State of New York, we have
relied upon the Opinion and have assumed without independent investigation the
correctness of the matters set forth therein, our opinions expressed below
being subject to the assumptions, qualifications and limitations set forth in
the Opinion.

     Based upon and subject to the foregoing, and subject to the
qualifications set forth below, we are of the following opinion:

     1.     The Credit Agreement is, and the Notes, upon delivery for value
received, will be, the legal, valid and binding obligation of the Borrower,
enforceable against the Borrower in accordance with its terms.

     2.      The Guaranty is the legal, valid and binding obligation of the
Parent, enforceable against the Parent in accordance with its terms.

     Our opinion is subject to the following qualifications:

     (a)     The enforceability of the obligations of the Borrower under
the Credit Agreement and the Notes and of the Parent under the Guaranty is
subject to the effect of any applicable bankruptcy, insolvency, fraudulent
conveyance, reorganization, moratorium or similar law affecting creditors'
rights generally.

     (b)     The enforceability of the obligations of the Borrower under the
Credit Agreement and the Notes and of the Parent under the Guaranty is subject
to the effect of general principles of equity, including (without limitation)
concepts of materiality, reasonableness, good faith and fair dealing
(regardless of whether considered in a proceeding in equity or at law).  Such
principles of equity are of general application, and, in applying such
principles, a court, among other things, might not allow a contracting party
to exercise remedies in respect of a default deemed immaterial, or might
decline to order an obligor to perform covenants.


                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxvii
<PAGE>
 
     (c)     We note further that, in addition to the application of equitable
principles described above, courts have imposed an obligation on contracting
parties to act reasonably and in good faith in the exercise of their
contractual rights and remedies, and may also apply public policy
considerations in limiting the right of parties seeking to obtain
indemnification under circumstances involving securities laws or where the
conduct of such parties is determined to have constituted negligence.

     (d)     We express no opinion herein as to (i) Section 9.05 of the Credit
Agreement, (ii) Section 12 of the Guaranty, (iii) the enforceability of
provisions purporting to grant to a party conclusive rights of determination,
(iv) the availability of specific performance or other equitable remedies, (v)
the enforceability of rights to indemnity under federal or state securities
laws or  (vi) the enforceability of waivers by parties of their respective
rights and remedies under law.

     (e)     Our opinions expressed above are limited to the law of the State
of New York, and we do not express any opinion herein concerning any other
law.  Without limiting the generality of the foregoing, we express no opinion
as to the effect of the law of any jurisdiction other than the State of New
York wherein any Lender may be located or wherein enforcement of the Credit
Agreement or the Notes may be sought that limits the rates of interest legally
chargeable or collectible.

     The foregoing opinion is solely for your benefit and may not be relied
upon by any other Person other than any Person that may become a Lender under
the Credit Agreement after the date hereof.

                                   Very truly yours,







                         SIGNATURE PAGE TO THE GUARANTY
                                    xxxviii
<PAGE>
 
                                   EXHIBIT H


                             TERMS OF SUBORDINATION



                  [The following provisions are to be included
                   in each instrument or document evidencing
                 loans from the Parent to the Borrower pursuant
                to Section 6.02(b)(iii) of the Credit Agreement]


     1.     Reference is made to the Amended and Restated Credit Agreement,
dated as of November 15, 1996 (such agreement, as it may hereafter be amended,
modified or supplemented from time to time, being the "CREDIT AGREEMENT"; the
terms defined therein and not otherwise defined herein being used herein as
therein defined), among Unicom Enterprises Inc., the Lenders named therein and
Citibank, N.A., as Agent for the Lenders.  The Parent hereby agrees for the
benefit of the Agent and the Lenders that all obligations of the Borrower to
the Parent hereunder (the "SUBORDINATED DEBT") are and shall be subordinate,
to the extent and in the manner set forth hereinafter, in right of payment to
the prior payment in full of all obligations of the Borrower under the Credit
Agreement and the other Loan Documents, whether for principal, interest
(including interest, as provided in the Loan Documents, after the filing of a
petition initiating any proceeding referred to in paragraph 3, below), fees,
expenses or otherwise (all such obligations being the "SENIOR DEBT").

     2.     Upon the occurrence and during the continuance of an Event of
Default or an Unmatured Default, the Parent shall not ask, demand, sue for,
take or receive from the Borrower, directly or indirectly, in cash or other
property or by set-off or in any other manner (including, without limitation,
from or by way of collateral), payment of all or any of the Subordinated Debt.

     3.     Upon any distribution of all or any of the assets of the Borrower
to creditors of the Borrower upon the dissolution, winding up, liquidation,
arrangement, reorganization or composition of the Borrower, whether in any
bankruptcy, insolvency, arrangement, reorganization, receivership or similar
proceedings or upon an assignment for the benefit of creditors or any other
marshalling of the assets and liabilities of the Borrower or otherwise, any
payment or distribution of any kind (whether in cash, property or securities)
which otherwise would be payable or deliverable upon or with respect to the


                         SIGNATURE PAGE TO THE GUARANTY
                                     xxxix
<PAGE>
 
Subordinated Debt shall be paid or delivered directly to the Agent for the
benefit of the Agent and the Lenders for application (in the case of cash) to
or as collateral (in the case of non-cash property or securities) for the
payment or prepayment of the Senior Debt until the Senior Debt shall have been
paid in full.  For the purposes of these provisions, the Senior Debt shall not
be deemed to have been paid in full until the Agent and the Lenders shall have
indefeasibly received payment in full of the Senior Debt in cash.

     4.     Until such time as the Senior Debt shall have been paid in full,
if any proceeding referred to in paragraph 3, above, is commenced by or
against the Borrower, the Agent is hereby irrevocably authorized and empowered
(in its own name, on behalf of the Lenders, in the name of the Parent, or
otherwise), but shall have no obligation, to demand, sue for, collect and
receive every payment or distribution referred to in paragraph 3, above, and
give acquittance therefor and to file claims and proofs of claim and take such
other action (including, without limitation, voting the Subordinated Debt or
enforcing any Lien securing payment of the Subordinated Debt) as it may deem
necessary or advisable for the exercise or enforcement of any of the rights or
interests of the Lenders hereunder.

     5.     All payments or distributions upon or with respect to the
Subordinated Debt which are received by the Parent contrary to the provisions
hereof shall be received in trust for the benefit of the Agent and the
Lenders, shall be segregated from other funds and property held by the Parent
and shall be forthwith paid over to the Agent for the benefit of the Agent and
the Lenders in the same form as so received (with any necessary endorsement)
to be applied (in the case of cash) to or held as collateral (in the case of
non-cash property or securities) for the payment or prepayment of the Senior
Debt in accordance with the terms of the Loan Documents.

     6.     The Agent is hereby authorized to demand specific performance of
these terms of subordination, whether or not the Borrower shall have complied
with any of the provisions hereof applicable to it, at any time when the
Parent shall have failed to comply with any of such provisions applicable to
it.  The Parent hereby irrevocably waives any defense based on the adequacy of
a remedy at law which might be asserted as a bar to such remedy of specific perf
ormance.

     7.     So long as any of the Senior Debt shall remain unpaid, the Parent
shall not (i) commence, or join with any creditor other than the Agent and the
Lenders in commencing, any involuntary proceeding referred to in paragraph 3,
above, or (i) declare any default in payment due hereunder or sue for breach
of the terms hereof, if and so long as payment hereunder would not be
permissible pursuant to paragraph 2 above.


                         SIGNATURE PAGE TO THE GUARANTY
                                     x1
<PAGE>
 
     8.     No payment or distribution to the Agent and the Lenders pursuant
to the above provisions shall entitle the Parent to exercise any rights of
subrogation in respect thereof until the Senior Debt shall have been paid in
full.

     9.     The holders of the Senior Debt may, at any time and from time to
time, without any consent of or notice to the Parent or any other holder of
the Subordinated Debt and without impairing or releasing the obligations of
the Parent under these terms of subordination:  (i) change the manner, place
or terms of payment or change or extend the time of payment of, or increase
the amount of, renew or alter, the Senior Debt (including any change in the
interest rate under which any of the Senior Debt is outstanding); (ii) sell,
exchange, release, not perfect and otherwise deal with any property at any
time pledged, assigned or mortgaged to secure the Senior Debt; (iii) release
anyone liable in any manner under or in respect of the Senior Debt; (iv)
exercise or refrain from exercising any rights against the Borrower and
others; and (v) apply any sums from time to time received to the Senior Debt.

     10.     The foregoing provisions regarding subordination are for the
benefit of the holders of the Senior Debt and shall be enforceable by them
directly against the holders of any Subordinated Debt, and no holder of the
Senior Debt shall be prejudiced in its right to enforce subordination of any
of the Subordinated Debt by any act or failure to act by the Borrower or
anyone in custody of its assets or property.  No such provisions may be
amended or modified without the prior written consent of the Agent and the
Lenders.


                         SIGNATURE PAGE TO THE GUARANTY
                                      x1i