<TABLE> <S> <C>

<PAGE>


<ARTICLE> UT
<LEGEND> This schedule contains summary financial information extracted from the
Consolidated Balance Sheet and Statement of Consolidated Capitalization as of
March 31, 2000 and the related Statement of Consolidated Operations,
Comprehensive Income, Retained Earnings and Cash Flows for the three months
ended March 31, 2000 and is qualified in its entirety by reference to such
financial statements.
</LEGEND>
<CIK>        0000022606
<NAME>       Commonwealth Edison Company
<MULTIPLIER>   1,000

<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                        DEC-31-2000
<PERIOD-START>                           JAN-01-2000
<PERIOD-END>                             MAR-31-2000
<BOOK-VALUE>                                PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                 12,098,852
<OTHER-PROPERTY-AND-INVEST>                2,786,203
<TOTAL-CURRENT-ASSETS>                     2,204,736
<TOTAL-DEFERRED-CHARGES>                           0<F1>
<OTHER-ASSETS>                             3,853,979
<TOTAL-ASSETS>                            20,943,770
<COMMON>                                   2,678,041
<CAPITAL-SURPLUS-PAID-IN>                  2,207,353
<RETAINED-EARNINGS>                          564,608
<TOTAL-COMMON-STOCKHOLDERS-EQ>             4,289,248<F2>
<PREFERRED-MANDATORY>                              0
<PREFERRED>                                    8,655
<LONG-TERM-DEBT-NET>                       6,800,066<F3>
<SHORT-TERM-NOTES>                                 0<F1>
<LONG-TERM-NOTES-PAYABLE>                          0<F1><F3>
<COMMERCIAL-PAPER-OBLIGATIONS>                     0<F1>
<LONG-TERM-DEBT-CURRENT-PORT>                677,691
<PREFERRED-STOCK-CURRENT>                     69,475
<CAPITAL-LEASE-OBLIGATIONS>                  132,099
<LEASES-CURRENT>                             140,862
<OTHER-ITEMS-CAPITAL-AND-LIAB>             8,825,674<F4>
<TOT-CAPITALIZATION-AND-LIAB>             20,943,770
<GROSS-OPERATING-REVENUE>                  1,559,815
<INCOME-TAX-EXPENSE>                          39,111
<OTHER-OPERATING-EXPENSES>                 1,287,782
<TOTAL-OPERATING-EXPENSES>                 1,326,893
<OPERATING-INCOME-LOSS>                      232,922
<OTHER-INCOME-NET>                           103,464<F5><F6>
<INCOME-BEFORE-INTEREST-EXPEN>               336,386
<TOTAL-INTEREST-EXPENSE>                     130,060
<NET-INCOME>                                 206,326
<PREFERRED-STOCK-DIVIDENDS>                    1,222
<EARNINGS-AVAILABLE-FOR-COMM>                205,104
<COMMON-STOCK-DIVIDENDS>                      73,498
<TOTAL-INTEREST-ON-BONDS>                          0<F7>
<CASH-FLOW-OPERATIONS>                     (351,245)
<EPS-BASIC>                                        0<F7>
<EPS-DILUTED>                                      0<F7>
<FN>
<F1> This item is not disclosed as a separate line item on the Consolidated
     Balance Sheet.

<F2> Includes other comprehensive income of $8,569 thousand and deductions of
     $1,156,786 thousand for treasury stock and $12,537 thousand for capital
     stock and warrant expense.

<F3> $3,530,121 thousand of notes and transitional trust notes are included in
     LONG-TERM-DEBT-NET.

<F4> Includes $350,000 thousand of Company-obligated mandatorily redeemable
     preferred securities of subsidiary trusts holding solely the Company's
     subordinated debt securities.

<F5> Includes $7,428 thousand of provision for preferred securities dividends of
     subsidiary trusts holding solely the Company's subordinated debt
     securities.

<F6> Includes an extraordinary loss of $2,744 thousand related to the early
     redemption of long-term debt during the first quarter of 2000.

<F7> This item is not disclosed as a separate line item on the Statement of
     Consolidated Operations.
</FN>


</TABLE>