<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 June 30, 1997 and the related Statements of Consolidated Income, Retained 
Earnings and Cash Flows for the six months ended June 30, 1997, and is qualified
in its entirety by reference to such financial statements. 
</LEGEND>
<CIK>      0000918040
<NAME>     Unicom Corporation
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               JUN-30-1997
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                   17,036,688
<OTHER-PROPERTY-AND-INVEST>                  2,008,114
<TOTAL-CURRENT-ASSETS>                       1,459,600
<TOTAL-DEFERRED-CHARGES>                             0<F1>
<OTHER-ASSETS>                               3,019,620
<TOTAL-ASSETS>                              23,524,022
<COMMON>                                     4,936,836
<CAPITAL-SURPLUS-PAID-IN>                            0
<RETAINED-EARNINGS>                          1,098,457
<TOTAL-COMMON-STOCKHOLDERS-EQ>               6,031,775<F2>
<PREFERRED-MANDATORY>                          202,035<F3>
<PREFERRED>                                    507,103<F3>
<LONG-TERM-DEBT-NET>                         5,820,182<F4>
<SHORT-TERM-NOTES>                               7,750
<LONG-TERM-NOTES-PAYABLE>                            0<F4>
<COMMERCIAL-PAPER-OBLIGATIONS>                 256,000
<LONG-TERM-DEBT-CURRENT-PORT>                  534,077
<PREFERRED-STOCK-CURRENT>                       43,574<F3>
<CAPITAL-LEASE-OBLIGATIONS>                    524,574
<LEASES-CURRENT>                               136,232
<OTHER-ITEMS-CAPITAL-AND-LIAB>               9,460,720<F5>
<TOT-CAPITALIZATION-AND-LIAB>               23,524,022
<GROSS-OPERATING-REVENUE>                    3,401,595
<INCOME-TAX-EXPENSE>                            93,087<F6>
<OTHER-OPERATING-EXPENSES>                   2,915,997
<TOTAL-OPERATING-EXPENSES>                   3,011,204
<OPERATING-INCOME-LOSS>                        390,391
<OTHER-INCOME-NET>                            (45,135)<F6><F7>
<INCOME-BEFORE-INTEREST-EXPEN>                 347,376
<TOTAL-INTEREST-EXPENSE>                       253,861
<NET-INCOME>                                    93,515
<PREFERRED-STOCK-DIVIDENDS>                          0<F7>
<EARNINGS-AVAILABLE-FOR-COMM>                   93,515
<COMMON-STOCK-DIVIDENDS>                       173,048
<TOTAL-INTEREST-ON-BONDS>                            0<F8>
<CASH-FLOW-OPERATIONS>                         847,688
<EPS-PRIMARY>                                     0.43
<EPS-DILUTED>                                        0
<FN>

<F1> This item is not disclosed as a separate line item on the Consolidated 
     Balance Sheet.

<F2> Includes a deduction of $3,518 thousand for preference stock expense of 
     ComEd.

<F3> Preferred and Preference stocks of ComEd.

<F4> $956,022 thousand of notes and long-term notes payable to banks is included
     in LONG-TERM-DEBT-NET.

<F5> Includes $350,000 thousand of ComEd-obligated mandatorily redeemable 
     preferred securities of subsidiary trusts.

<F6> A tax benefit of $2,120 thousand related to nonoperating activities is 
     included in INCOME-TAX-EXPENSE.

<F7> A $31,012 thousand provision for preferred and preference stock dividends 
     of ComEd and $14,076 thousand provision for preferred securities dividends 
     of subsidiary trusts are included in OTHER-INCOME-NET.

<F8> This item is not disclosed as a separate line item on the Statement of 
     Consolidated Income. 

</FN>
        

</TABLE>