<PAGE>

                                                                     EXHIBIT 4-6



                       ____________ SUPPLEMENTAL INDENTURE

                      Dated as of ________________ __, 200_

                                     Between

                           COMMONWEALTH EDISON COMPANY

                                       and

                            WILMINGTON TRUST COMPANY



<PAGE>




                                TABLE OF CONTENTS


<TABLE>
<S>                                                                                                              <C>
ARTICLE I. DEFINITIONS............................................................................................1

     Section 1.1  Definition of Terms.............................................................................1
     Section 1.2  Interpretation..................................................................................5


ARTICLE II. GENERAL TERMS AND CONDITIONS OF.......................................................................5

     Section 2.1  Designation and Principal Amount................................................................5
     Section 2.2  Maturity........................................................................................5
     Section 2.3  Form and Payment................................................................................5
     Section 2.4  Global Note.....................................................................................6
     Section 2.5  Interest........................................................................................6

ARTICLE III. REDEMPTION OF THE NOTES..............................................................................7

     Section 3.1  Special Event Redemption........................................................................7
     Section 3.2  Optional Redemption by Company..................................................................8
     Section 3.3  No Sinking Fund.................................................................................8

ARTICLE IV. EXTENSION OF INTEREST PAYMENT PERIOD..................................................................8

     Section 4.1  Extension of Interest Payment Period............................................................8
     Section 4.2  Notice of Extension.............................................................................9

ARTICLE V. EXPENSES..............................................................................................10

     Section 5.1  Payment of Expenses............................................................................10
     Section 5.2  Payment Upon Resignation or Removal............................................................10

ARTICLE VI. SUBORDINATION........................................................................................10

     Section 6.1  Agreement to Subordinate.......................................................................10
     Section 6.2  Default on Senior Indebtedness.................................................................11
     Section 6.3  Liquidation; Dissolution; Bankruptcy...........................................................11
     Section 6.4  Subrogation....................................................................................12
     Section 6.5  Trustee to Effectuate Subordination............................................................13
     Section 6.6  Notice by the Company..........................................................................13
     Section 6.7  Rights of the Trustee; Holders of Senior Indebtedness..........................................14
     Section 6.8  Subordination May Not Be Impaired..............................................................15

ARTICLE VII. COVENANT TO LIST ON EXCHANGE........................................................................15

     Section 7.1  Listing on Exchange............................................................................15
</TABLE>



<PAGE>






<TABLE>
<S>                                                                                                             <C>
ARTICLE VIII. FORM OF NOTE.......................................................................................15

     Section 8.1  Form of Note...................................................................................15

ARTICLE IX. ORIGINAL ISSUE OF NOTES..............................................................................23

     Section 9.1  Original Issue of Notes........................................................................23

ARTICLE X. MISCELLANEOUS.........................................................................................23

     Section 10.1  Ratification of Indenture.....................................................................23
     Section 10.2  Trustee Not Responsible for Recitals..........................................................23
     Section 10.3  Governing Law.................................................................................24
     Section 10.4  Separability..................................................................................24
     Section 10.5  Counterparts..................................................................................24
</TABLE>



                                       3
<PAGE>


                  THIS ___________ SUPPLEMENTAL INDENTURE, dated as of _________
__, 200_ (the "_______ Supplemental Indenture"), is between Commonwealth Edison
Company, an Illinois corporation (the "Company"), and Wilmington Trust Company,
not in its individual capacity but solely as trustee (the "Trustee") under the
Indenture dated as of September 1, 1995 between the Company and the Trustee, as
supplemented by a First Supplemental Indenture, dated as of September 19, 1995
(the "Indenture").

                              W I T N E S S E T H:

                  WHEREAS, the Company executed and delivered the Indenture to
the Trustee to provide for the future issuance of the Company's unsecured
subordinated debt securities, to be issued from time to time in one or more
series as might be determined by the Company under the Indenture, in an
unlimited aggregate principal amount which may be authenticated and delivered as
provided in the Indenture; and

                  WHEREAS, pursuant to the terms of the Indenture, the Company
desires to provide for the establishment of a new series of its Debt Securities
to be known as its ___% ______________ due __________ __, 20__ (the "Notes"),
the form and substance of such Notes and the terms, provisions and conditions
thereof to be set forth as provided in the Indenture and this _______
Supplemental Indenture; and

                  WHEREAS, ComEd Financing III, a Delaware statutory trust (the
"Trust"), has offered to the public $__________ aggregate stated liquidation
amount of its ____% trust preferred securities (the "Preferred Securities") and
has offered to the Company $____________ aggregate stated liquidation amount of
its trust common securities (the "Common Securities"), such Preferred Securities
and Common Securities representing undivided beneficial interests in the assets
of the Trust, and proposes to invest the proceeds from such offerings in
$__________ aggregate principal amount of the Notes; and

                  WHEREAS, the Company has requested that the Trustee execute
and deliver this _______ Supplemental Indenture, and all requirements necessary
to make this _______ Supplemental Indenture a valid instrument, in accordance
with its terms, and to make the Notes, when executed by the Company and
authenticated and delivered by the Trustee, the valid obligations of the
Company, have been performed, and the execution and delivery of this _______
Supplemental Indenture has been duly authorized in all respects.

                  NOW, THEREFORE, in consideration of the purchase and
acceptance of the Notes by the holders thereof, and for the purpose of setting
forth, as provided in the Indenture, the form and substance of the Notes and the
terms, provisions and conditions thereof, the Company covenants and agrees with
the Trustee as follows:

                                   ARTICLE I.
                                   DEFINITIONS

                  Section 1.1 Definition of Terms. Unless the context otherwise
requires:




                                       1
<PAGE>





                  (a) a term defined in the Indenture has the same meaning when
used in this _______ Supplemental Indenture,

                  (b) a term defined anywhere in this _______ Supplemental
Indenture has the same meaning throughout and

                  (c) the following terms have the meanings given to them in the
Declaration: (i) Clearing Agency; (ii) Delaware Trustee; (iii) Distributions;
(iv) Property Trustee; and (v) Administrative Trustees.

                  In addition, the following terms have the following respective
meanings:

                  "Additional Interest" shall have the meaning set forth in
         Section 2.5(d).

                  "Common Securities" shall have the meaning set forth in the
         recitals of this ______________ Supplemental Indenture.

                  "Company" shall have the meaning set forth in the preamble of
         this ____________ Supplemental Indenture.

                  "Compounded Interest" shall have the meaning set forth in
         Section 4.1.

                  "Coupon Rate" shall have the meaning set forth in Section
         2.5(a).

                  "Declaration" means the Amended and Restated Declaration of
         Trust of ComEd Financing III, a Delaware statutory trust, dated as of
         ______________.

                  "Deferred Interest" shall have the meaning set forth in
         Section 4.1.

                  "Depositary", with respect to the Notes, means The Depository
         Trust Company or such other successor Clearing Agency for the Preferred
         Securities.

                  "Dissolution Event" means that, as a result of the occurrence
         and continuation of a Special Event, the Trust is to be dissolved in
         accordance with the Declaration and the Notes held by the Property
         Trustee are to be distributed to the holders of the Trust Securities
         issued by the Trust pro rata in accordance with the Declaration.

                  "Extension Period" shall have the meaning set forth in Section
         4.1.

                  "Indenture" shall have the meaning set forth in the preamble
         of this ____________ Supplemental Indenture.

                  "Interest Payment Date" shall have the meaning set forth in
         Section 2.5(a).

                  "Investment Company" means an investment company as defined in
         the Investment Company Act.




                                       2
<PAGE>

                  "Investment Company Act" means the Investment Company Act of
         1940, as amended from time to time, or any successor legislation.

                  "Investment Company Event" means that the Company and the
         Trust shall have received an opinion of counsel experienced in practice
         under the Investment Company Act to the effect that, as a result of the
         occurrence of an amendment to, or change (including any announced
         proposed change) in, the laws or regulations of the United States or
         any political subdivision thereof or therein or any other governmental
         agency or regulatory authority (a "Change in 1940 Act Law"), there is
         more than an insubstantial risk that the Trust is or will be considered
         an Investment Company which is required to be registered under the
         Investment Company Act, which Change in 1940 Act Law becomes effective
         on or after the date of the prospectus supplement relating to the
         issuance of the Preferred Securities.

                  "Maturity Date" means the date on which the Notes mature and
         on which the principal shall be due and payable together with all
         accrued and unpaid interest thereon including Compounded Interest and
         Additional Interest, if any.

                  "Non Book-Entry Preferred Securities" shall have the meaning
         set forth in Section 2.4(b).

                  "Notes" shall have the meaning set forth in the recitals of
         this ______________ Supplemental Indenture.

                  "Optional Redemption Price" shall have the meaning set forth
         in Section 3.2.

                  "Preferred Securities" shall have the meaning set forth in the
         recitals of this ______________ Supplemental Indenture.

                  "Preferred Security Certificate" means a certificate
         representing a Preferred Security substantially in the form of Exhibit
         C to the Declaration.

                  "Senior Indebtedness" means (i) any payment in respect of (A)
         indebtedness of the Company for money borrowed and (B) indebtedness
         evidenced by securities, debentures, bonds, notes or other similar
         instruments issued by the Company including, without limitation,
         indebtedness evidenced by securities issued pursuant to the provisions
         of the Mortgage dated July 1, 1923, as supplemented by Supplemental
         Indenture dated August 1, 1944 and subsequent supplemental indentures,
         between the Company, as mortgagor, and BNY Midwest Trust Company and
         D.G. Donovan, as trustees; the Indenture dated as of September 1, 1987,
         as supplemented and amended, between the Company and Citibank, N.A., as
         trustee; the Indentures dated April 1, 1949, October 1, 1949, October
         1, 1950, October 1, 1954, January 1, 1958, January 1, 1959 and December
         1, 1961, between the Company and Amalgamated Bank, as successor trustee
         to The First National Bank of Chicago; and the Indenture dated February
         15, 1973, as supplemented, between the Company and Amalgamated Bank, as
         successor trustee to The First National


                                       3
<PAGE>

         Bank of Chicago; (ii) all capital lease obligations of the Company;
         (iii) all obligations of the Company issued or assumed as the deferred
         purchase price of property, all conditional sale obligations of the
         Company and all obligations of such obligor under any title retention
         agreement (but excluding trade accounts payable arising in the ordinary
         course of business); (iv) all obligations of the Company for
         reimbursement on any letter of credit, banker's acceptance, security
         purchase facility or similar credit transaction; (v) all obligations of
         the type referred to in clauses (i) through (iv) of other persons for
         the payment of which the Company is responsible or liable as obligor,
         guarantor or otherwise; and (vi) all obligations of the type referred
         to in clauses (i) through (v) of other persons secured by any lien on
         any property or asset of the Company (whether or not such obligation is
         assumed by such obligor), except for (1) any such indebtedness that is
         by its terms subordinated to or pari passu with the Notes, as the case
         may be, including all other debt securities and guarantees in respect
         of those debt securities, issued to any other trusts, partnerships or
         any other entity affiliated with the Company which is a financing
         vehicle of the Company ("Financing Entity") in connection with an
         issuance of preferred securities by such Financing Entity or other
         securities which rank pari passu with, or junior to, the Preferred
         Securities, and (2) any indebtedness between or among the Company and
         its Affiliates.

                  "Special Event" means an Investment Company Event or Tax
         Event.

                  "Special Redemption Price" shall have the meaning set forth in
         Section 3.1.

                  "Tax Event" means that the Company and the Trust shall have
         received an opinion of a nationally recognized independent tax counsel
         experienced in such matters to the effect that, as a result of (a) any
         amendment to, or change (including any announced proposed change) in,
         the laws (or any regulations thereunder) of the United States or any
         political subdivision or taxing authority thereof or therein, or (b)
         any interpretation or application of, or pronouncement with respect to,
         such laws or regulations by any legislative body, court, governmental
         or administrative agency or body, or regulatory authority (including
         the enactment of any legislation and the publication of any judicial
         decision or regulatory or administrative determination), which
         amendment or change is effective, or which interpretation, application
         or pronouncement is issued or announced, on or after the date of the
         prospectus supplement relating to the issuance of the Preferred
         Securities, there is more than an insubstantial risk that (i) the Trust
         is or will be subject to United States federal income tax with respect
         to income or gain received, accrued or realized on or with respect to
         the Notes, (ii) interest payable to the Trust by the Company on the
         Notes is not, or will not be, deductible by the Company (or by a member
         of the Company's "affiliated group," within the meaning of section 1504
         of the Internal Revenue Code of 1986, as amended, that files a
         consolidated federal income tax return with the Company), in whole or
         in part, for United States federal income tax purposes, or (iii) the
         Trust is or will be subject to more than a de minimis amount of other
         taxes, duties or other governmental charges.




                                       4
<PAGE>

                  "Trust" shall have the meaning set forth in the recitals of
         this ___________ Supplemental Indenture.

                  "Trustee" shall have the meaning set forth in the preamble of
         this ____________ Supplemental Indenture.

                  "Underwriting Agreement" means the Underwriting Agreement,
         dated as of ____________, __, 200_, among the Company, the Trust and
         the Underwriters named therein.

                  Section 1.2 Interpretation. Each definition in this _______
Supplemental Indenture includes the singular and the plural, and references to
the neuter gender include the masculine and feminine where appropriate. Terms
which relate to accounting matters shall be interpreted in accordance with
generally accepted accounting principles in effect from time to time. References
to any statute mean such statute as amended at the time and include any
successor legislation. The word "or" is not exclusive, and the words "herein,"
"hereof" and "hereunder" refer to this _______ Supplemental Indenture as a
whole. The headings to the Articles and Sections are for convenience of
reference and shall not affect the meaning or interpretation of this _______
Supplemental Indenture. References to Articles and Sections mean the Articles
and Sections of this _______ Supplemental Indenture.

                                   ARTICLE II.

                         GENERAL TERMS AND CONDITIONS OF

                                    THE NOTES

                  Section 2.1 Designation and Principal Amount. There is hereby
authorized a series of Debt Securities designated the "___% ______________ due
________ __, 20__," limited in aggregate principal amount to $____________,
which amount shall be as set forth in any written order of the Company for the
authentication and delivery of Notes pursuant to Section 2.04 of the Indenture.

                  Section 2.2 Maturity. The Maturity Date will be
______________, __, 20__.

                  Section 2.3 Form and Payment. Except as provided in Section
2.4, the Notes shall be issued in fully registered certificated form without
interest coupons. Principal and interest (including Compounded Interest and
Additional Interest, if any) on the Notes issued in certificated form will be
payable, the transfer of such Notes will be registrable and such Notes will be
exchangeable for Notes bearing identical terms and provisions at the office or
agency of the Trustee in Wilmington, Delaware, provided, however, that payment
of interest may be made at the option of the Company by check mailed to the
registered holder at such address as shall appear in the Security Register,
except in the case of Notes represented by a Global Security. Notwithstanding
the foregoing, so long as the registered holder of any Notes is the Property
Trustee, the payment of the principal of and interest (including Compounded
Interest and



                                       5
<PAGE>





                  Additional Interest, if any) on such Notes held by the
Property Trustee will be made at such place and to such account as may be
designated by the Property Trustee.

                  Section 2.4 Global Note. In connection with a Dissolution
         Event:

                  (a) the Notes in certificated form may be presented to the
         Trustee by the Property Trustee in exchange for a Global Security in an
         aggregate principal amount equal to the aggregate principal amount of
         the Notes so presented, to be registered in the name of the Depositary,
         or its nominee, and delivered by the Trustee to the Depositary for
         crediting to the accounts of its participants pursuant to the
         instructions of the Administrative Trustees. The Company, upon any such
         presentation, shall execute a Global Security in such aggregate
         principal amount and deliver the same to the Trustee for authentication
         and delivery in accordance with the Indenture and this _______
         Supplemental Indenture. Payments on the Notes issued as a Global
         Security will be made to the Depositary; and

                  (b) if any Preferred Securities are held in non book-entry
         certificated form, the Notes in certificated form may be presented to
         the Trustee by the Property Trustee and any Preferred Security
         Certificate which represents Preferred Securities other than Preferred
         Securities held by the Clearing Agency or its nominee ("Non Book-Entry
         Preferred Securities") will be deemed to represent beneficial interests
         in Notes presented to the Trustee by the Property Trustee having an
         aggregate principal amount equal to the aggregate stated liquidation
         amount of the Non Book-Entry Preferred Securities until such Preferred
         Security Certificates are presented to the Security Registrar for
         transfer or reissuance at which time such Preferred Security
         Certificates will be cancelled and a Note, registered in the name of
         the holder of the Preferred Security Certificate or the transferee of
         the holder of such Preferred Security Certificate, as the case may be,
         with an aggregate principal amount equal to the aggregate stated
         liquidation amount of the Preferred Security Certificate cancelled,
         will be executed by the Company and delivered to the Trustee for
         authentication and delivery in accordance with the Indenture and this
         _______ Supplemental Indenture. On issue of such Notes, Notes with an
         equivalent aggregate principal amount that were presented by the
         Property Trustee to the Trustee will be deemed to have been cancelled.

                  Section 2.5 Interest. (a) Each Note will bear interest at the
rate of ___% per annum (the "Coupon Rate") from the original date of issuance
until the principal thereof becomes due and payable, and on any overdue
principal, premium, if any, and (to the extent that payment of such interest is
enforceable under applicable law) on any overdue installment of interest at the
Coupon Rate, compounded quarterly, payable (subject to the provisions of Article
IV) quarterly in arrears on __________, __________, __________, and __________,
of each year (each, an "Interest Payment Date"), commencing on __________ __,
200_, to the Person in whose name such Note or any predecessor Note is
registered, at the close of business on the regular record date for such
interest installment, which, in respect of (i) Notes of which the Property
Trustee is the registered holder and the Preferred Securities are in book-entry
only form or (ii) a Global Security, shall be the close of business on the
Business Day next preceding that Interest Payment Date. Notwithstanding the
foregoing sentence, if (i) the Notes are held by the



                                       6
<PAGE>


Property Trustee and the Preferred Securities are no longer in book-entry only
form or (ii) the Notes are not represented by a Global Security, the Company may
select a regular record date at least ten Business Days before an Interest
Payment Date.

                  (b) The amount of interest payable for any period will be
computed on the basis of a 360-day year of twelve 30-day months. In the event
that any date on which interest is payable on the Notes is not a Business Day,
then payment of interest payable on such date will be made on the next
succeeding day which is a Business Day (and without any interest or other
payment in respect of any such delay), except that, if such Business Day is in
the next succeeding calendar year, such payment shall be made on the immediately
preceding Business Day, in each case with the same force and effect as if made
on such date. The amount of interest payable for any period shorter than a full
quarterly period for which interest is computed, will be computed on the basis
of the actual number of days elapsed in such a 90-day quarter.

                  (c) The Company may, at its option and in accordance with
Section 4.03 of the Indenture, appoint a paying agent for the Notes. If a paying
agent has been appointed by the Company, the paying agent, unless the Company
shall otherwise determine and so notify the paying agent, shall calculate the
amount of interest payable on the Notes on each Interest Payment Date. All
certificates, communications, opinions, determinations, calculations, quotations
and decisions given, expressed, made or obtained for the purposes of the
provisions relating to the payment and calculation of interest on the Notes, by
the paying agent, will (in the absence of willful default, bad faith or manifest
error) be binding on the Trust, the Company, the Trustee and all holders of the
Notes, and no liability will (in the absence of willful default, bad faith or
manifest error) attach to the paying agent in connection with the exercise or
non-exercise by any of them of their powers, duties and discretion.

                  (d) If a Tax Event has occurred and is continuing at any time
while the Property Trustee is the holder of any Notes, and the Trust or the
Property Trustee is required to pay any taxes, duties, assessments or other
governmental charges of whatever nature (other than withholding taxes) imposed
by the United States, or any other taxing authority, then, in any case, the
Company will pay as additional interest ("Additional Interest") on the Notes
held by the Property Trustee, such additional amounts as shall be required so
that the net amounts received and retained by the Trust and the Property Trustee
after paying such taxes, duties, assessments or other governmental charges will
be equal to the amounts the Trust and the Property Trustee would have received
had no such taxes, duties, assessments or other government charges been imposed
as a result of such Tax Event.

                                  ARTICLE III.

                             REDEMPTION OF THE NOTES

                  Section 3.1 Special Event Redemption. If a Special Event has
occurred and is continuing then, notwithstanding Section 3.2(a), the Company
shall have the right upon not less than 30 days nor more than 60 days notice to
the registered holders of the Notes to redeem the Notes, in whole, but not in
part, for cash within 90 days following the occurrence of such Special



                                       7
<PAGE>


Event at a redemption price equal to 100% of the principal amount to be redeemed
plus any accrued and unpaid interest thereon to the date of such redemption (the
"Special Redemption Price"). The Company may, at its option, in lieu of
redemption, pursue any opportunity to eliminate a Special Event by taking some
ministerial action, such as filing a form or making an election or pursuing some
other measure that has no adverse effect on the Company, the Trust or the
holders of the Trust Securities issued by the Trust. The Special Redemption
Price shall be paid prior to 12:00 noon, New York time, on the date of such
redemption or at such earlier time as the Company determines and specifies in
the notice of redemption, provided the Company shall deposit with the Trustee an
amount sufficient to pay the Special Redemption Price by 11:00 a.m. on the date
such Special Redemption Price is to be paid.

                  Section 3.2 Optional Redemption by Company. (a) Subject to the
provisions of Article III of the Indenture and to Section 3.2(b), the Company
shall have the right to redeem the Notes, in whole or in part, from time to
time, on or after ___________ __, 200_, at a redemption price equal to 100% of
the principal amount to be redeemed plus any accrued and unpaid interest
thereon, including Additional Interest, if any, to the date of such redemption
(the "Optional Redemption Price"). Any redemption pursuant to this paragraph
will be made upon not less than 30 days nor more than 60 days notice to the
registered holder of the Notes, at the Optional Redemption Price. If the Notes
are only partially redeemed pursuant to this Section 3.2, the Notes will be
redeemed pro rata or by lot or by any other method utilized by the Trustee;
provided, that if at the time of redemption, the Notes are registered as a
Global Security, the Depositary shall determine, in accordance with its
procedures, the principal amount of such Notes beneficially held by each holder
of a Note be redeemed. The Optional Redemption Price shall be paid prior to
12:00 noon, New York time, on the date of such redemption or at such earlier
time as the Company determines and specifies in the notice of redemption,
provided the Company shall deposit with the Trustee an amount sufficient to pay
the Optional Redemption Price by 11:00 a.m. on the date such Optional Redemption
Price is to be paid.

                  (b) If a partial redemption of the Notes would result in the
delisting of the Preferred Securities issued by the Trust from any national
securities exchange or other organization on which the Preferred Securities are
then listed, the Company shall not be permitted to effect such partial
redemption and may only redeem the Notes in whole.

                  Section 3.3 No Sinking Fund. The Notes are not entitled to the
benefit of any sinking fund.

                                   ARTICLE IV.

                      EXTENSION OF INTEREST PAYMENT PERIOD

                  Section 4.1 Extension of Interest Payment Period. So long as
no Event of Default has occurred and is continuing, the Company shall have the
right, at any time and from time to time during the term of the Notes, to extend
the interest payment period of such Notes for up to twenty (20) consecutive
quarters (an "Extension Period"), during which Extension Period no interest
shall be due and payable; provided, that no Extension Period shall extend beyond
the



                                       8
<PAGE>

Maturity Date. To the extent permitted by applicable law, interest, the payment
of which has been deferred because of the extension of the interest payment
period pursuant to this Section 4.1, will bear interest compounded quarterly at
the Coupon Rate for each quarter of the Extension Period ("Compounded
Interest"). At the end of the Extension Period, the Company shall pay all
interest accrued and unpaid on the Notes, including any Compounded Interest and
Additional Interest (together, "Deferred Interest") which shall be payable to
the holders of the Notes in whose names the Notes are registered in the Security
Register on the first record date after the end of the Extension Period. Before
the termination of any Extension Period, the Company may further extend such
period, provided that such period together with all such further extensions
thereof shall not exceed twenty (20) consecutive quarters or extend beyond the
Maturity Date of the Notes. Upon the termination of any Extension Period and
upon the payment of all Deferred Interest then due, the Company may select a new
Extension Period, subject to the foregoing requirements. No interest shall be
due and payable during an Extension Period, except at the end thereof, but the
Company may prepay at any time all or any portion of the interest accrued during
any Extension Period. Compounded Interest and Additional Interest shall each be
treated as interest for all purposes under the Indenture and this _______
Supplemental Indenture.

                  Section 4.2 Notice of Extension. (a) If the Property Trustee
is the only registered holder of the Notes at the time the Company selects an
Extension Period, the Company shall give written notice to the Administrative
Trustees, the Property Trustee and the Trustee of its selection of such
Extension Period one Business Day before the earlier of (i) the next succeeding
date on which Distributions on the Trust Securities issued by the Trust are
payable, or (ii) the date the Trust is required to give notice of the record or
payment date for such Distributions to the New York Stock Exchange or other
applicable self-regulatory organization or to holders of the Preferred
Securities issued by the Trust, but in any event at least one Business Day
before such record date.

                  (b) If the Property Trustee is not the only holder of the
Notes at the time the Company selects an Extension Period, the Company shall
give the holders of the Notes and the Trustee written notice of its selection of
such Extension Period at least ten (10) Business Days before the earlier of (i)
the next succeeding Interest Payment Date, or (ii) the date the Company is
required to give notice of the record or payment date of such interest payment
to the New York Stock Exchange or other applicable self-regulatory organization
or to holders of the Notes.

                  (c) The quarter in which any notice is given pursuant to
paragraphs (a) or (b) of this Section 4.2 shall be counted as one of the twenty
(20) quarters permitted in the maximum Extension Period permitted under Section
4.1.




                                       9
<PAGE>
                                   ARTICLE V.

                                    EXPENSES

                  Section 5.1 Payment of Expenses. In connection with the
offering, sale and issuance of the Notes to the Property Trustee in connection
with the sale of the Trust Securities by the Trust, the Company, in its capacity
as borrower with respect to the Notes, shall:

                  (a) pay all costs and expenses relating to the offering, sale
         and issuance of the Notes, including commissions to the underwriters
         payable pursuant to the Underwriting Agreement and compensation of the
         Trustee under the Indenture in accordance with the provisions of
         Section 7.06 of the Indenture;

                  (b) pay all costs and expenses of the Trust (including, but
         not limited to, costs and expenses relating to the organization of the
         Trust, the offering, sale and issuance of the Trust Securities
         (including commissions to the underwriters in connection therewith),
         the fees and expenses of the Property Trustee and the Delaware Trustee,
         the costs and expenses relating to the operation of the Trust,
         including without limitation, costs and expenses of accountants,
         attorneys, statistical or bookkeeping services, expenses for printing
         and engraving and computing or accounting equipment, paying agent(s),
         registrar(s), transfer agent(s), duplicating, travel and telephone and
         other telecommunications expenses and costs and expenses incurred in
         connection with the acquisition, financing, and disposition of Trust
         assets); and

                  (c) pay any and all taxes (other than United States
         withholding taxes attributable to the Trust or its assets) and all
         liabilities, costs and expenses with respect to such taxes of the
         Trust.

                  Section 5.2 Payment Upon Resignation or Removal. Upon
termination of this ________ Supplemental Indenture or the Indenture or the
removal or resignation of the Trustee, the Company shall pay to the Trustee all
amounts accrued under Section 7.06 of the Indenture to the date of such
termination, removal or resignation. Upon termination of the Declaration or the
removal or resignation of the Delaware Trustee or the Property Trustee, as the
case may be, pursuant to Section 8.10 of the Declaration, the Company shall pay
to the Delaware Trustee or the Property Trustee, as the case may be, all amounts
accrued under Section 8.06 of the Declaration to the date of such termination,
removal or resignation.



                                   ARTICLE VI.

                                  SUBORDINATION

                  Section 6.1 Agreement to Subordinate. The Company covenants
and agrees, and each holder of Notes issued hereunder by such holder's
acceptance thereof likewise covenants


                                       10
<PAGE>

and agrees, that all Notes shall be issued subject to the provisions of this
Article VI; and each holder of a Note, whether upon original issue or upon
transfer or assignment thereof, accepts and agrees to be bound by such
provisions.

                  The payment by the Company of the principal of, premium, if
any, and interest on all Notes issued hereunder shall, to the extent and in the
manner hereinafter set forth, be subordinated and subject in right of payment to
the prior payment in full of all Senior Indebtedness of the Company, whether
outstanding at the date of this _______ Supplemental Indenture or thereafter
incurred.

                  No provision of this Article VI shall prevent the occurrence
of any default or Event of Default hereunder.

                  Section 6.2 Default on Senior Indebtedness. In the event and
during the continuation of any default by the Company in the payment of
principal, premium, interest or any other payment due on any Senior Indebtedness
of the Company, or in the event that the maturity of any Senior Indebtedness of
the Company has been accelerated because of a default, then, in either case, no
payment shall be made by the Company with respect to the principal (including
redemption and sinking fund payments) of, or premium, if any, or interest on the
Notes.

                  In the event that, notwithstanding the foregoing, any payment
shall be received by the Trustee or any holder when such payment is prohibited
by the preceding paragraph of this Section 6.2, such payment shall be held in
trust for the benefit of, and shall be paid over or delivered to, the holders of
Senior Indebtedness or their respective representatives, or to the trustee or
trustees under any indenture pursuant to which any of such Senior Indebtedness
may have been issued, as their respective interests may appear, but only to the
extent that the holders of the Senior Indebtedness (or their representative or
representatives or a trustee) notify the Trustee within 90 days of such payment
of the amounts then due and owing on the Senior Indebtedness and only the
amounts specified in such notice to the Trustee shall be paid to the holders of
Senior Indebtedness.

                  Section 6.3 Liquidation; Dissolution; Bankruptcy. Upon any
payment by the Company, or distribution of assets of the Company of any kind or
character, whether in cash, property or securities, to creditors upon any
dissolution or winding-up or liquidation or reorganization of the Company,
whether voluntary or involuntary or in bankruptcy, insolvency, receivership or
other proceedings, all amounts due upon all Senior Indebtedness of the Company
shall first be paid in full, or payment thereof provided for in money in
accordance with its terms, before any payment is made by the Company on account
of the principal (and premium, if any) or interest on the Notes; and upon any
such dissolution or winding-up or liquidation or reorganization, any payment by
the Company, or distribution of assets of the Company of any kind or character,
whether in cash, property or securities, to which the holders of the Notes or
the Trustee would be entitled to receive from the Company, except for the
provisions of this Article VI, shall be paid by the Company or by any receiver,
trustee in bankruptcy, liquidating trustee, agent or other Person making such
payment or distribution, or by the holders of the Notes or by



                                       11
<PAGE>

the Trustee under this Indenture if received by them or it, directly to the
holders of Senior Indebtedness of the Company (pro rata to such holders on the
basis of the respective amounts of Senior Indebtedness held by such holders, as
calculated by the Company) or their representative or representatives, or to the
trustee or trustees under any indenture pursuant to which any instruments
evidencing such Senior Indebtedness may have been issued, as their respective
interests may appear, to the extent necessary to pay such Senior Indebtedness in
full, in money or money's worth, after giving effect to any concurrent payment
or distribution to or for the holders of such Senior Indebtedness, before any
payment or distribution is made to the holders of Notes or to the Trustee.

                  In the event that, notwithstanding the foregoing, any payment
or distribution of assets of the Company of any kind or character, whether in
cash, property or securities, prohibited by the foregoing, shall be received by
the Trustee or the holders of the Notes before all Senior Indebtedness of the
Company is paid in full, or provision is made for such payment in money in
accordance with its terms, such payment or distribution shall be held in trust
for the benefit of and shall be paid over or delivered to the holders of such
Senior Indebtedness or their representative or representatives, or to the
trustee or trustees under any indenture pursuant to which any instruments
evidencing such Senior Indebtedness may have been issued, as their respective
interests may appear, as calculated by the Company, for application to the
payment of all Senior Indebtedness of the Company remaining unpaid to the extent
necessary to pay such Senior Indebtedness in full in money in accordance with
its terms, after giving effect to any concurrent payment or distribution to or
for the benefit of the holders of such Senior Indebtedness.

                  For purposes of this Article VI, the words "cash, property or
securities" shall not be deemed to include shares of stock of the Company as
reorganized or readjusted, or securities of the Company or any other corporation
provided for by a plan of reorganization or readjustment, the payment of which
is subordinated at least to the extent provided in this Article VI with respect
to the Notes to the payment of all Senior Indebtedness of the Company that may
at the time be outstanding, provided that (i) such Senior Indebtedness is
assumed by the new corporation, if any, resulting from any such reorganization
or readjustment, and (ii) the rights of the holders of such Senior Indebtedness
are not, without the consent of such holders, altered by such reorganization or
readjustment. The consolidation of the Company with, or the merger of the
Company into, another corporation or the liquidation or dissolution of the
Company following the conveyance or transfer of its property as an entirety, or
substantially as an entirety, to another corporation upon the terms and
conditions provided for in Article X of the Indenture shall not be deemed a
dissolution, winding-up, liquidation or reorganization for the purposes of this
Section 6.3 if such other corporation shall, as a part of such consolidation,
merger, conveyance or transfer, comply with the conditions stated in Article X
of the Indenture. Nothing in Section 6.2 or in this Section 6.3 shall apply to
claims of, or payments to, the Trustee under or pursuant to Section 7.06 of the
Indenture.

                  Section 6.4 Subrogation. Subject to the payment in full of all
Senior Indebtedness of the Company, the rights of the holders of the Notes shall
be subrogated to the rights of the holders of such Senior Indebtedness to
receive payments or distributions of cash,


                                       12
<PAGE>


property or securities of the Company applicable to such Senior Indebtedness
until the principal of (and premium, if any) and interest on the Notes shall be
paid in full; and, for the purposes of such subrogation, no payments or
distributions to the holders for such Senior Indebtedness of any cash, property
or securities to which the holders of the Notes or the Trustee would be entitled
except for the provisions of this Article VI, and no payment over pursuant to
the provisions of this Article VI, to or for the benefit of the holders of such
Senior Indebtedness by holders of the Notes or the Trustee, shall, as between
the Company, its creditors other than holders of Senior Indebtedness of the
Company, and the holders of the Notes be deemed to be a payment by the Company
to or on account of such Senior Indebtedness. It is understood that the
provisions of this Article VI are and are intended solely for the purposes of
defining the relative rights of the holders of the Notes, on the one hand, and
the holders of such Senior Indebtedness on the other hand.

                  Nothing contained in this Article VI or elsewhere in this
Indenture or in the Notes is intended to or shall impair, as between the
Company, its creditors other than the holders of Senior Indebtedness of the
Company, and the holders of the Notes, the obligation of the Company which is
absolute and unconditional, to pay to the holders of the Notes the principal of
(and premium, if any) and interest on the Notes as and when the same shall
become due and payable in accordance with their terms, or is intended to or
shall affect the relative rights of the holders of the Notes and creditors of
the Company, other than the holders of Senior Indebtedness of the Company, nor
shall anything herein or therein prevent the Trustee or the holder of any Note
from exercising all remedies otherwise permitted by applicable law upon default
under the Indenture, subject to the rights, if any, under this Article VI of the
holders of such Senior Indebtedness in respect of cash, property or securities
of the Company, received upon the exercise of any such remedy.

                  Upon any payment or distribution of assets of the Company
referred to in this Article VI, the Trustee, subject to the provisions of
Section 7.01 of the Indenture, and the holders of the Notes, shall be entitled
to rely upon any order or decree made by any court of competent jurisdiction in
which such dissolution, winding-up, liquidation or reorganization proceedings
are pending, or a certificate of the receiver, trustee in bankruptcy,
liquidation trustee, agent or other Person making such payment or distribution,
delivered to the Trustee or to the holders of the Notes, for the purposes of
ascertaining the Persons entitled to participate in such distribution, the
holders of Senior Indebtedness and other indebtedness of the Company, the amount
thereof or payable thereon, the amount or amounts paid or distributed thereon
and all other facts pertinent thereto or to this Article VI.

                  Section 6.5 Trustee to Effectuate Subordination. Each holder
of a Note by such holder's acceptance thereof authorizes and directs the Trustee
on such holder's behalf to take such action as may be necessary or appropriate
to effectuate the subordination provided in this Article VI and appoints the
Trustee such holder's attorney-in-fact for any and all such purposes.

                  Section 6.6 Notice by the Company. The Company shall give
prompt written notice to a Responsible Officer of the Trustee of any fact known
to the Company that would prohibit the making of any payment of monies to or by
the Trustee in respect of the Notes



                                       13
<PAGE>

pursuant to the provisions of this Article VI. Notwithstanding the provisions of
this Article VI or any other provision of the Indenture and this _______
Supplemental Indenture, the Trustee shall not be charged with knowledge of the
existence of any facts that would prohibit the making of any payment of monies
to or by the Trustee in respect of the Notes pursuant to the provisions of this
Article VI unless and until a Responsible Officer of the Trustee shall have
received written notice thereof at the Principal Office of the Trustee from the
Company or a holder or holders of Senior Indebtedness or from any trustee
therefor; and before the receipt of any such written notice, the Trustee,
subject to the provisions of Section 7.01 of the Indenture, shall be entitled in
all respects to assume that no such facts exist; provided, however, that if the
Trustee shall not have received the notice provided for in this Section 6.6 at
least two Business Days prior to the date upon which by the terms hereof any
money may become payable for any purpose (including, without limitation, the
payment of the principal of (or premium, if any) or interest on any Note), then,
anything herein contained to the contrary notwithstanding, the Trustee shall
have full power and authority to receive such money and to apply the same to the
purposes for which they were received, and shall not be affected by any notice
to the contrary that may be received by it within two Business Days prior to
such date.

                  The Trustee, subject to the provisions of Section 7.01 of the
Indenture, shall be entitled to rely on the delivery to it of a written notice
by a Person representing himself to be a holder of Senior Indebtedness of the
Company (or a trustee on behalf of such holder) to establish that such notice
has been given by a holder of such Senior indebtedness or a trustee on behalf of
any such holder or holders. In the event that the Trustee determines in good
faith that further evidence is required with respect to the right of any Person
as a holder of such Senior Indebtedness to participate in any payment or
distribution pursuant to this Article VI, the Trustee may request such Person to
furnish evidence to the reasonable satisfaction of the Trustee as to the amount
of such Senior Indebtedness held by such Person, the extent to which such Person
is entitled to participate in such payment or distribution and any other facts
pertinent to the rights of such Person under this Article VI, and if such
evidence is not furnished, the Trustee may defer any payment to such Person
pending judicial determination as to the right of such Person to receive such
payment.

                  Section 6.7 Rights of the Trustee; Holders of Senior
Indebtedness. The Trustee in its individual capacity shall be entitled to all
the rights set forth in this Article VI in respect of any Senior Indebtedness at
any time held by it, to the same extent as any other holder of Senior
Indebtedness, and nothing in this Indenture shall deprive the Trustee of any of
its rights as such holder.

                  With respect to the holders of Senior Indebtedness of the
Company, the Trustee undertakes to perform or to observe only such of its
covenants and obligations as are specifically set forth in this Article VI, and
no implied covenants or obligations with respect to the holders of such Senior
Indebtedness shall be read into this Indenture against the Trustee. The Trustee
shall not be deemed to owe any fiduciary duty to the holders of such Senior
Indebtedness and, subject to the provisions of Section 7.01 of the Indenture,
the Trustee shall not be liable to any holder of such Senior Indebtedness if it
shall pay over or deliver to holders of Notes, the Company or any



                                       14
<PAGE>

other Person money or assets to which any holder of such Senior Indebtedness
shall be entitled by virtue of this Article VI or otherwise.

                  Section 6.8 Subordination May Not Be Impaired. No right of any
present or future holder of any Senior Indebtedness of the Company to enforce
subordination as herein provided shall at any time or in any way be prejudiced
or impaired by any act or failure to act on the part of the Company or by any
act or failure to act, in good faith, by any such holder, or by any
noncompliance by the Company with the terms, provisions and covenants of the
Indenture, regardless of any knowledge thereof that any such holder may have or
otherwise be charged with.

                  Without in any way limiting the generality of the foregoing
paragraph, the holders of Senior Indebtedness of the Company may, at any time
and from time to time, without the consent of or notice to the Trustee or the
holders of the Notes, without incurring responsibility to the holders of the
Notes and without impairing or releasing the subordination provided in this
Article VI or the obligations hereunder of the holders of the Notes to the
holders of such Senior Indebtedness, do any one or more the following: (i)
change the manner, place or terms of payment or extend the time of payment of,
or renew or alter, such Senior Indebtedness, or otherwise amend or supplement in
any manner such Senior Indebtedness or any instrument evidencing the same or any
agreement under which such Senior Indebtedness is outstanding; (ii) sell,
exchange, release or otherwise deal with any property pledged, mortgaged or
otherwise securing such Senior Indebtedness; (iii) release any Person liable in
any manner for the collection of such Senior Indebtedness; and (iv) exercise or
refrain from exercising any rights against the Company and any other Person.

                                  ARTICLE VII.

                          COVENANT TO LIST ON EXCHANGE

                  Section 7.1 Listing on Exchange. If the Notes are to be issued
as a Global Security in connection with the distribution of the Notes to the
holders of the Preferred Securities issued by the Trust upon a Dissolution
Event, the Company will use its commercially reasonable best efforts to list
such Notes on the New York Stock Exchange or on such other exchange as the
Preferred Securities are then listed.

                                  ARTICLE VIII.

                                  FORM OF NOTE

                  Section 8.1 Form of Note. The Notes and the Trustee's
Certificate of Authentication to be endorsed thereon are to be substantially in
the following forms:




                                       15
<PAGE>





                             (FORM OF FACE OF NOTE)

                  [IF THE NOTE IS TO BE A GLOBAL SECURITY, INSERT: This Note is
a Global Security within the meaning of the Indenture hereinafter referred to
and is registered in the name of a Depository or a nominee of a Depository. This
Note is exchangeable for Notes registered in the name of a person other than the
Depository or its nominee only in the limited circumstances described in the
Indenture, and no transfer of this Note (other than a transfer of this Note as a
whole by the Depository to a nominee of the Depository or by a nominee of the
Depository to the Depository or another nominee of the Depository) may be
registered except in limited circumstances.

                  Unless this Note is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
Note issued is registered in the name of Cede & Co. or such other name as
requested by an authorized representative of The Depository Trust Company and
any payment hereon is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE
HEREOF FOR VALUE OR OTHERWISE BY A PERSON IS WRONGFUL since the registered owner
hereof, Cede & Co., has an interest herein.]




                                       16
<PAGE>

No. ______________________             $__________________

CUSIP No.________________


                           COMMONWEALTH EDISON COMPANY

                        ____% __________________________

                            DUE ___________ __, 20__

                  COMMONWEALTH EDISON COMPANY, an Illinois corporation (the
"Company", which term includes any successor corporation under the Indenture
hereinafter referred to), for value received, hereby promises to pay to _______
or registered assigns, the principal sum of ____________ Dollars ($___________)
on __________ __, 20__, and to pay interest on said principal sum from
__________ __, 200_ or from the most recent interest payment date (each such
date, an "Interest Payment Date") to which interest has been paid or duly
provided for, quarterly (subject to deferral as set forth herein) in arrears on
_____________, _________, _________ and __________ of each year, commencing
__________ __, 200_, at the rate of ____% per annum until the principal hereof
shall have become due and payable, and on any overdue principal and premium, if
any, and (without duplication and to the extent that payment of such interest is
enforceable under applicable law) on any overdue installment of interest
compounded quarterly at the same rate per annum. The amount of interest payable
on any Interest Payment Date shall be computed on the basis of a 360-day year of
twelve 30-day months. In the event that any date on which interest is payable on
this Note is not a Business Day, then payment of interest payable on such date
will be made on the next succeeding day which is a Business Day (and without any
interest or other payment in respect of any such delay), except that, if such
Business Day is in the next succeeding calendar year, such payment shall be made
on the immediately preceding Business Day, in each case with the same force and
effect as if made on such date. The interest installment so payable, and
punctually paid or duly provided for, on any Interest Payment Date will, as
provided in the Indenture, be paid to the person in whose name this Note (or one
or more Predecessor Securities, as defined in said Indenture) is registered at
the close of business on the regular record date for such interest installment.
In the case of a Global Security or any Notes of which the Property Trustee is
the holder, such regular record date which, in respect of (i) Notes of which the
Property Trustee is the registered holder and the Preferred Securities are in
book-entry only form or (ii) a Global Security, shall be the close of business
on the Business Day next preceding that Interest Payment Date. Notwithstanding
the foregoing sentence, if (i) the Notes are held by the Property Trustee and
the Preferred Securities are no longer in book-entry only form or (ii) the Notes
are not represented by a Global Security, the Company may select a regular
record date at least one Business Day before an Interest Payment Date. Any such
interest installment not punctually paid or duly provided for shall forthwith
cease to be payable to the registered holders on such regular record date, and
may be paid to the Person in whose name this Note (or one or more Predecessor
Securities) is registered at the close of business on a special record date to
be fixed by the Trustee for the payment of such defaulted interest, notice
whereof shall be given to the



                                       17
<PAGE>

registered holders of this series of Notes not less than ten (10) days prior to
such special record date, or may be paid at any time in any other lawful manner
not inconsistent with the requirements of any securities exchange on which the
Notes may be listed, and upon such notice as may be required by such exchange,
all as more fully provided in the Indenture. The principal of (and premium, if
any) and the interest (including Compounded Interest and Additional Interest, if
any) on this Note shall be payable at the office or agency of the Trustee
maintained for that purpose in Wilmington, Delaware, in any coin or currency of
the United States of America which at the time of payment is legal tender for
payment of public and private debts; provided, however, that payment of interest
may be made at the option of the Company by check mailed to the registered
holder at such address as shall appear in the Security Register. Notwithstanding
the foregoing, so long as the holder of this Note is the Property Trustee, the
payment of the principal of (and premium, if any) and interest on this Note will
be made at such place and to such account as may be designated by the Property
Trustee.

                  The indebtedness evidenced by this Note is, to the extent
provided in the Indenture, subordinate and junior in right of payment to the
prior payment in full of all Senior Indebtedness, and this Note is issued
subject to the provisions of the Indenture with respect thereto. Each holder of
this Note, by accepting the same, (a) agrees to and shall be bound by such
provisions, (b) authorizes and directs the Trustee on his behalf to take such
action as may be necessary or appropriate to acknowledge or effectuate the
subordination so provided and (c) appoints the Trustee his attorney-in-fact for
any and all such purposes. Each holder hereof, by his acceptance hereof, hereby
waives all notice of the acceptance of the subordination provisions contained
herein and in the Indenture by each holder of Senior Indebtedness, whether now
outstanding or hereafter incurred, and waives reliance by each such Holder upon
said provisions.

                  This Note shall not be entitled to any benefit under the
Indenture hereinafter referred to, be valid or become obligatory for any purpose
until the Certificate of Authentication hereon shall have been signed by or on
behalf of the Trustee.

                  The provisions of this Note are continued on the reverse side
hereof and such continued provisions shall for all purposes have the same effect
as though fully set forth at this place.




                                       18
<PAGE>

                  IN WITNESS WHEREOF, the Company has caused this instrument to
be executed.


Dated:                                 COMMONWEALTH EDISON COMPANY

                                       By

                                                  [Title]

Attest:


By
         Secretary


                     (FORM OF CERTIFICATE OF AUTHENTICATION)

                          CERTIFICATE OF AUTHENTICATION

         This is one of the Notes of the series of Notes described in the
within-mentioned Indenture.



                                       WILMINGTON TRUST COMPANY,
                                       Not in its individual capacity but solely
                                       as Trustee

                                       By

                                            Authorized Signatory

                            (FORM OF REVERSE OF NOTE)

                  This Note is one of a duly authorized series of Notes of the
Company (herein sometimes referred to as the "Notes"), specified in the
Indenture, all issued or to be issued in one or more series under and pursuant
to an Indenture dated as of September 1, 1995, duly executed and delivered
between the Company and Wilmington Trust Company, not in its individual capacity
but solely as trustee (the "Trustee"), as supplemented by the First Supplemental
Indenture, dated as of September 19, 1995 between the Company and the Trustee
and by the _______ Supplemental Indenture dated as of __________ __, 200_
between the Company and the Trustee (the Indenture as so supplemented, the
"Indenture"), to which Indenture and all indentures supplemental thereto
reference is hereby made for a description of the rights,



                                       19
<PAGE>

limitations of rights, obligations, duties and immunities thereunder of the
Trustee, the Company and the holders of the Notes. By the terms of the
Indenture, the Notes are issuable in series which may vary as to amount, date of
maturity, rate of interest and in other respects as provided in the Indenture.
This series of Notes is limited in aggregate principal amount as specified in
said _______ Supplemental Indenture.

                  Upon the occurrence and continuation of a Special Event (which
means a Tax Event or an Investment Company Event, each of which are defined
below), the Company shall have the right upon not less than 30 days nor more
than 60 days notice to redeem the Notes in whole, but not in part, for cash at
the principal amount together with any interest accrued thereon (the "Special
Redemption Price") within 90 days following the occurrence of such Special
Event. The Special Redemption Price shall be paid prior to 12:00 noon, New York
time, on the date of such redemption or at such earlier time as the Company
determines. In addition, the Company shall have the right to redeem this Note at
the option of the Company, without premium or penalty, in whole or in part, from
time to time, on or after __________ __, 20__ (an "Optional Redemption"), at a
redemption price equal to 100% of the principal amount plus any accrued but
unpaid interest, including Additional Interest, if any, to the date of such
redemption (the "Optional Redemption Price"). Any optional redemption pursuant
to this paragraph will be made upon not less than 30 days nor more than 60 days
notice, at the Optional Redemption Price. If the Notes are only partially
redeemed by the Company pursuant to an Optional Redemption, the Notes will be
redeemed pro rata or by lot or by any other method utilized by the Trustee;
provided, that if at the time of redemption, the Notes are registered as a
Global Security, the Depositary shall determine the principal amount of such
Notes beneficially held by each holder of a Note to be redeemed.

                  "Investment Company Event" means that the Company and the
Trust shall have received an opinion of counsel experienced in practice under
the Investment Company Act to the effect that, as a result of the occurrence of
an amendment to, or change (including any announced proposed change) in, the
laws or regulations of the United States or any political subdivision thereof or
therein or any other governmental agency or regulatory authority (a "Change in
1940 Act Law"), there is more than an insubstantial risk that the Trust is or
will be considered an Investment Company which is required to be registered
under the Investment Company Act, which Change in 1940 Act Law becomes effective
on or after the date of the prospectus supplement relating to the issuance of
the Preferred Securities.

                  "Tax Event" means that the Company and the Trust shall have
received an opinion of a nationally recognized independent tax counsel
experienced in such matters to the effect that, as a result of (a) any amendment
to, or change (including any announced proposed change) in, the laws (or any
regulations thereunder) of the United States or any political subdivision or
taxing authority thereof or therein, or (b) any interpretation or application
of, or pronouncement with respect to, such laws or regulations by any
legislative body, court, governmental or administrative agency or body, or
regulatory authority (including the enactment of any legislation and the
publication of any judicial decision or regulatory or administrative
determination), which amendment or change is effective, or which interpretation,
application or pronouncement is issued or announced, on or after the date of the
prospectus supplement relating


                                       20
<PAGE>

to the issuance of the Preferred Securities, there is more than an insubstantial
risk that (i) the Trust is or will be subject to United States federal income
tax with respect to income or gain received, accrued or realized on or with
respect to the Notes, (ii) interest payable to the Trust by the Company on the
Notes is not, or will not be, deductible by the Company (or by a member of the
Company's "affiliated group," within the meaning of section 1504 of the Internal
Revenue Code of 1986, as amended, that files a consolidated federal income tax
return with the Company), in whole or in part, for United States federal income
tax purposes, or (iii) the Trust is or will be subject to more than a de minimis
amount of other taxes, duties or other governmental charges.

                  In the event of redemption of this Note in part only, a new
Note or Notes of this series for the unredeemed portion hereof will be issued in
the name of the holder hereof upon the cancellation hereof.

                  In case an Event of Default, as defined in the Indenture,
shall have occurred and be continuing, the principal of all of the Notes may be
declared, and upon such declaration shall become, due and payable, in the
manner, with the effect and subject to the conditions provided in the Indenture.

                  The Indenture contains provisions permitting the Company and
the Trustee, with the consent of the holders of not less than a majority in
aggregate principal amount of the Notes of each series affected at the time
outstanding, as defined in the Indenture, to execute supplemental indentures for
the purpose of adding any provisions to or changing in any manner or eliminating
any of the provisions of the Indenture or of any supplemental indenture or of
modifying in any manner the rights of the holders of the Notes; provided,
however, that no such supplemental indenture shall (i) extend the fixed maturity
of any Notes of any series, or reduce the principal amount thereof, or reduce
the rate or extend the time of payment of interest thereon, or reduce any
premium payable upon the redemption thereof, without the consent of the holder
of each Note so affected or (ii) reduce the aforesaid percentage of Notes, the
holders of which are required to consent to any such supplemental indenture,
without the consent of the holders of each Note then outstanding and affected
thereby. The Indenture also contains provisions permitting the holders of a
majority in aggregate principal amount of the Notes of any series at the time
outstanding affected thereby, on behalf of all of the holders of the Notes of
such series, to waive any past default in the performance of any of the
covenants contained in the Indenture, or established pursuant to the Indenture
with respect to such series, and its consequences, except a default in the
payment of the principal of or premium, if any, or interest on any of the Notes
of such series. Any such consent or waiver by the registered holder of this Note
(unless revoked as provided in the Indenture) shall be conclusive and binding
upon such holder and upon all future holders and owners of this Note and of any
Note issued in exchange herefor or in place hereof (whether by registration of
transfer or otherwise), irrespective of whether or not any notation of such
consent or waiver is made upon this Note.

                  No reference herein to the Indenture and no provision of this
Note or of the Indenture shall alter or impair the obligation of the Company,
which is absolute and


                                       21
<PAGE>

unconditional, to pay the principal of and premium, if any, and interest on this
Note at the time and place and at the rate and in the money herein prescribed.

                  So long as no Event of Default has occurred and is continuing,
the Company shall have the right at any time during the term of the Notes, from
time to time, to extend the interest payment period of such Notes for up to
twenty (20) consecutive quarters (an "Extension Period"), at the end of which
period the Company shall pay all interest then accrued and unpaid (together with
interest thereon at the rate specified for the Notes to the extent that payment
of such interest is enforceable under applicable law). In the event that the
Company exercises this right at any time when any Notes are held by the Trust or
the Property Trustee, then the Company shall not (i) declare or pay any
dividend, or make any distribution with respect to, or redeem, purchase or make
a liquidation payment with respect to, any of its capital stock, (ii) make any
payment of interest, principal or premium, if any, on or repay, repurchase or
redeem any debt securities (including guarantees) issued by the Company which
rank pari passu with or junior to the Notes and (iii) make any guarantee
payments with respect to the foregoing (other than pursuant to the Preferred
Securities Guarantee). Before the termination of any such Extension Period, the
Company may further extend such Extension Period, provided that such Extension
Period together with all such further extensions thereof shall not exceed twenty
(20) consecutive quarters or extend beyond the Maturity Date of the Notes. At
the termination of any such Extension Period and upon the payment of all accrued
and unpaid interest and any additional interest then due, the Company may select
a new Extension Period, subject to the foregoing requirements.

                  As provided in the Indenture and subject to certain
limitations therein set forth, this Note is transferable by the registered
holder hereof on the Security Register of the Company, upon surrender of this
Note for registration of transfer at the office or agency of the Trustee in
Wilmington, Delaware accompanied by a written instrument or instruments of
transfer in form satisfactory to the Company or the Trustee duly executed by the
registered holder hereof or his attorney duly authorized in writing, and
thereupon one or more new Notes of authorized denominations and for the same
aggregate principal amount and series will be issued to the designated
transferee or transferees. No service charge will be made for any such transfer,
but the Company may require payment of a sum sufficient to cover any tax or
other governmental charge payable in relation thereto.

                  Prior to due presentment for registration of transfer of this
Note, the Company, the Trustee, any paying agent and any Security Registrar may
deem and treat the registered holder hereof as the absolute owner hereof
(whether or not this Note shall be overdue and notwithstanding any notice of
ownership or writing hereon made by anyone other than the Security Registrar)
for the purpose of receiving payment of or on account of the principal hereof
and premium, if any, and interest due hereon and for all other purposes, and
neither the Company nor the Trustee nor any paying agent nor any Security
Registrar shall be affected by any notice to the contrary.

                  No recourse shall be had for the payment of the principal of
or the interest on this Note, or for any claim based hereon, or otherwise in
respect hereof, or based on or in respect of



                                       22
<PAGE>

the Indenture, against any incorporator, stockholder, officer or director, past,
present or future, as such, of the Company or of any predecessor or successor
corporation, whether by virtue of any constitution, statute or rule of law, or
by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the
issuance hereof, expressly waived and released.

                  [The Notes of this series are issuable only in registered form
without coupons in denominations of $25 and any integral multiple thereof.]
[This Global Security is exchangeable for Notes in definitive form only under
certain limited circumstances set forth in the Indenture. Notes of this series
so issued are issuable only in registered form without coupons in denominations
of $25 and any integral multiple thereof.] As provided in the Indenture and
subject to certain limitations [herein and] therein set forth, Notes of this
series [so issued] are exchangeable for a like aggregate principal amount of
Notes of this series of a different authorized denomination, as requested by the
Holder surrendering the same.

                  All terms used in this Note which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

                                   ARTICLE IX.

                             ORIGINAL ISSUE OF NOTES

                  Section 9.1 Original Issue of Notes. Notes in the aggregate
principal amount of $_____________ may, upon execution of this _______
Supplemental Indenture, be executed by the Company and delivered to the Trustee
for authentication, and the Trustee shall thereupon authenticate and deliver
said Notes to or upon the written order of the Company, signed by its President
or any Vice President and its Treasurer or an Assistant Treasurer, without any
further action by the Company.

                                   ARTICLE X.

                                  MISCELLANEOUS

                  Section 10.1 Ratification of Indenture. The Indenture, as
supplemented by this _______ Supplemental Indenture, is in all respects ratified
and confirmed, and this _______ Supplemental Indenture shall be deemed part of
the Indenture in the manner and to the extent herein and therein provided.

                  Section 10.2 Trustee Not Responsible for Recitals. The
recitals herein contained are made by the Company and not by the Trustee, and
the Trustee assumes no responsibility for the correctness thereof. The Trustee
makes no representation as to the validity or sufficiency of this _______
Supplemental Indenture.




                                       23
<PAGE>





                  Section 10.3 Governing Law. This _______ Supplemental
Indenture and each Note shall be deemed to be a contract made under the internal
laws of the State of New York, and for all purposes shall be construed in
accordance with the laws of said State.

                  Section 10.4 Separability. In case any one or more of the
provisions contained in this _______ Supplemental Indenture or in the Notes
shall for any reason be held to be invalid, illegal or unenforceable in any
respect, such invalidity, illegality or unenforceability shall not affect any
other provisions of this _______ Supplemental Indenture or of the Notes, but
this _______ Supplemental Indenture and the Notes shall be construed as if such
invalid or illegal or unenforceable provision had never been contained herein or
therein.

                  Section 10.5 Counterparts. This _______ Supplemental Indenture
may be executed in any number of counterparts each of which shall be an
original; but such counterparts shall together constitute but one and the same
instrument.




                                       24
<PAGE>






                  IN WITNESS WHEREOF, the parties hereto have caused this
_______ Supplemental Indenture to be duly executed, and their respective
corporate seals to be hereunto affixed and attested, on the date or dates
indicated in the acknowledgements and as of the day and year first above
written.


                                    COMMONWEALTH EDISON COMPANY


                                    By:
                                         Title:




Attest:


         Title:


                                    WILMINGTON TRUST COMPANY,
                                    Not in Its Individual Capacity
                                    But Solely as Trustee


                                    By:
                                         Title:




Attest:


         Title:








                                       25
<PAGE>

STATE OF ILLINOIS )
COUNTY OF COOK    ) ss:


                  On the day of September, 1995, before me personally came
______________, to me known, who, being by me duly sworn, did depose and say
that he is a _______________ of COMMONWEALTH EDISON COMPANY, one of the
corporations described in and which executed the above instrument; that he knows
the corporate seal of said corporation; that the seal affixed to the said
instrument is such corporate seal; that it was so affixed by authority of the
Board of Directors of said corporation, and that he signed his name thereto by
like authority.

                                            NOTARY PUBLIC

[seal]                                      Commission expires





STATE OF DELAWARE  )
COUNTY OF _________) ss:


                  On the day of September, 1995, before me personally came
____________, to me known, who, being by me duly sworn, did depose and say that
he is the ____________________ of WILMINGTON TRUST COMPANY, one of the
corporations described in and which executed the above instrument; that he knows
the corporate seal of said corporation; that the seal affixed to the said
instrument is such corporate seal; that it was so affixed by authority of the
Board of Directors of said corporation, and that he signed his name thereto by
like authority.


                                            NOTARY PUBLIC

[seal]                                      Commission expires







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