<TABLE> <S> <C>
<ARTICLE> UT
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET, CONSOLIDATED STATEMENT OF INCOME, AND
CONSOLIDATED STATEMENT OF CASH FLOWS OF NIAGARA MOHAWK HOLDINGS, INC.
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0001079182
<NAME> Niagara Mohawk Holdings, Inc.
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 5786115
<OTHER-PROPERTY-AND-INVEST> 456801
<TOTAL-CURRENT-ASSETS> 858842
<TOTAL-DEFERRED-CHARGES> 5448343
<OTHER-ASSETS> 97951
<TOTAL-ASSETS> 12648052
<COMMON> 1874
<CAPITAL-SURPLUS-PAID-IN> 2518919
<RETAINED-EARNINGS> 605708
<TOTAL-COMMON-STOCKHOLDERS-EQ> 2779166
59570
440000
<LONG-TERM-DEBT-NET> 5006891
<SHORT-TERM-NOTES> 0
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 0
<LONG-TERM-DEBT-CURRENT-PORT> 562038
7620
<CAPITAL-LEASE-OBLIGATIONS> 0
<LEASES-CURRENT> 0
<OTHER-ITEMS-CAPITAL-AND-LIAB> 3792767
<TOT-CAPITALIZATION-AND-LIAB> 12648052
<GROSS-OPERATING-REVENUE> 2240079
<INCOME-TAX-EXPENSE> 26662
<OTHER-OPERATING-EXPENSES> 1978682
<TOTAL-OPERATING-EXPENSES> 1978682
<OPERATING-INCOME-LOSS> 261397
<OTHER-INCOME-NET> (2365)
<INCOME-BEFORE-INTEREST-EXPEN> 259032
<TOTAL-INTEREST-EXPENSE> 220897
<NET-INCOME> 22327
15808
<EARNINGS-AVAILABLE-FOR-COMM> (5244)
<COMMON-STOCK-DIVIDENDS> 0
<TOTAL-INTEREST-ON-BONDS> 0
<CASH-FLOW-OPERATIONS> 398962
<EPS-BASIC> (.03)
<EPS-DILUTED> 0
</TABLE>
