Exhibit 10-27-1

                                 FIRST AMENDMENT
                                     TO THE
                           COMMONWEALTH EDISON COMPANY
                     SUPPLEMENTAL MANAGEMENT RETIREMENT PLAN

                  The Commonwealth Edison Company Supplemental Management
Retirement Plan, as amended and restated, effective January 1, 1998, and as
subsequently amended from time to time (the "Supplemental Plan") is hereby
further amended, effective as of the dates provided below, to clarify the class
of employees eligible to participate in the Supplemental Plan and to make
certain other changes:

                                        I

                  The Supplemental Plan is hereby amended effective January 1,
1997 as follows:

                  1. The second paragraph of Section 1.1 of the Supplemental
Plan is hereby amended by inserting at the end thereof the following new
sentence:

                  The portion of the Supplemental Plan that provides benefits
                  described in the first sentence of Section 4.1 is intended to
                  be an "excess benefit plan" as defined in Section 3(36) of the
                  Employee Retirement Income Security Act of 1974, as amended
                  ("ERISA").



                  2. Section 3.1 of the Supplemental Plan is hereby amended (a)
by deleting the words "the Limitations" that appear in the second sentence
contained therein and inserting in lieu thereof the words "the application of
Section 415 of the Code (the "415 Limitation")" and (b) by inserting at the end
thereof the following new sentence:

                  In addition, each Eligible Employee who is classified by an
                  Employer as a key management employee or an officer (a "Key
                  Management Employee") and who becomes entitled to a benefit
                  under the Qualified Plan which is reduced or limited by the
                  Limitations shall participate in the Supplemental Plan when
                  such individual becomes entitled to receive benefits under the
                  Qualified Plan.

                  3. Section 4.1 of the Supplemental Plan is hereby amended,
effective as of January 1, 1997, (a) by inserting the phrase ", other than a
Participant who is a Key Management Employee," immediately after the words
"described in Section 3.1" that are contained therein, (b) by deleting the word





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"Limitations" wherever it appears therein and inserting in lieu thereof the
words "415 Limitation" and (c) by inserting the following new sentence at the
end thereof:

                  If a Participant who is a Key Management Employee begins
                  receiving benefits under the Qualified Plan on his or her
                  Annuity Starting Date and, on that date, the retirement
                  benefit payable under the Qualified Plan to such Participant
                  is less than the retirement benefit that would be payable to
                  such Participant under the Qualified Plan but for the
                  application of the Limitations, then such Participant shall be
                  entitled to an annual benefit under the Excess Plan in an
                  amount equal to the excess of (A) minus (B) where:

                  (A)      equals the amount of annual benefit payable to such
                           Participant under the Qualified Plan if payments
                           thereunder were calculated without regard to the
                           Limitations, and

                  (B)      equals the amount of the annual benefit payable to
                           such Participant under the Qualified Plan.


                  4. Section 4.3 of the Supplemental Plan is hereby amended (a)
by deleting the phrase "but for the application of any Limitations" contained in
clause (I) therein and inserting in lieu thereof the phrase "but for, in the
case of a Participant described in Section 3.3 who is entitled to a survivor
benefit with respect to a Participant who is not a Key Management Employee,
application of the 415 Limitation, and in the case of a Participant described in
Section 3.3 who is entitled to a survivor benefit with respect to a Participant
who is a Key Management Employee, application of any Limitations" and (b) by
deleting the phrase "without giving effect to any Limitations" contained in
clause (I) of subparagraph (A) therein and inserting in lieu thereof the
following phrase "without giving effect to, in the case of a Participant
described in Section 3.3 who is entitled to a survivor benefit with respect to a
Participant who is not a Key Management Employee, the 415 Limitation, and in the
case of a Participant described in Section 3.3 who is entitled to a survivor
benefit with respect to a Participant who is a Key Management Employee, any
Limitations".

                  5. Section 5.1 of the Supplemental Plan is hereby amended by
deleting the word "Limitations" that appears therein and inserting in lieu
thereof the words "415 Limitation or any Limitations, whichever is applicable".



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<PAGE>

                  6. Section 6.1 of the Supplemental Plan is hereby amended (a)
by inserting the words "the first sentence of" immediately after the words
"Benefits provided under" that appear in the first sentence contained therein,
(b) by deleting the word "Limitations" that appears in the first sentence
contained therein and inserting in lieu thereof the words "415 Limitations", (c)
by inserting the phrase "the second sentence of Section 4.1 and under"
immediately after the words "Benefits provided under" that appear in the second
sentence contained therein and (d) by inserting the words "the first sentence
of" immediately after the words "other than as described in" that appear in the
second sentence contained therein.

                                       III

                  The Supplemental Plan is hereby amended effective January 1,
2001 as follows:

                  1. The name of the Supplemental Plan is hereby redesignated
"Exelon Corporation Supplemental Management Retirement Plan" and all references
to the name of the Supplemental Plan are hereby redesignated accordingly.

                  2. The words "Commonwealth Edison Company" wherever they
appear in the Supplemental Plan are hereby changed to "Exelon Corporation".

3.                    Section 1.1 of the Supplemental Plan is hereby amended (a)
                      by deleting the words "Commonwealth Edison Company Service
                      Annuity System" that appear in the first sentence of the
                      second paragraph contained therein and inserting in lieu
                      thereof the words "the Commonwealth Edison Company Service
                      Annuity System and the Exelon Corporation Cash Balance
                      Plan" and (b) by deleting the words "Qualified Plan"
                      wherever they appear therein and inserting in lieu thereof
                      the words "Qualified Plans".

                  4. Section 3.1 of the Supplemental Plan, as amended above, is
hereby further amended, by deleting the words "the Qualified Plan" wherever such
words appear and inserting in lieu thereof the words "any of the Qualified
Plans".





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<PAGE>

                  5. All references contained in the Supplemental Plan to "the
Qualified Plan" shall be changed to "the Qualified Plans".

                                       III

Except as herein amended, the Supplemental Plan shall remain in full force and
effect. Executed this 22nd day of December, 2000.
COMMONWEALTH EDISON COMPANY

By:      /s/ S. Gary Snodgrass
         --------------------------
         S. Gary Snodgrass
         Senior Vice President















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