<ARTICLE> UT <LEGEND> This schedule contains summary financial information extracted from the balance sheet, statement of income and statement of cash flows contained in Form 10-Q of Commonwealth Energy System for the three months ended June 30, 1998 and is qualified in its entirety by reference to such financial statements. </LEGEND> <CIK> 0000071304 <NAME> COMMONWEALTH ENERGY SYSTEM <MULTIPLIER> 1,000 <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-END> JUN-30-1998 <PERIOD-TYPE> 6-MOS <BOOK-VALUE> PER-BOOK <TOTAL-NET-UTILITY-PLANT> 1,087,498 <OTHER-PROPERTY-AND-INVEST> 14,191 <TOTAL-CURRENT-ASSETS> 152,765 <TOTAL-DEFERRED-CHARGES> 261,727 <OTHER-ASSETS> 0 <TOTAL-ASSETS> 1,516,181 <COMMON> 43,068 <CAPITAL-SURPLUS-PAID-IN> 112,043 <RETAINED-EARNINGS> 284,480 <TOTAL-COMMON-STOCKHOLDERS-EQ> 439,591 <PREFERRED-MANDATORY> 11,950 <PREFERRED> 0 <LONG-TERM-DEBT-NET> 343,164 <SHORT-TERM-NOTES> 226,625 <LONG-TERM-NOTES-PAYABLE> 0 <COMMERCIAL-PAPER-OBLIGATIONS> 0 <LONG-TERM-DEBT-CURRENT-PORT> 36,653 <PREFERRED-STOCK-CURRENT> 820 <CAPITAL-LEASE-OBLIGATIONS> 11,322 <LEASES-CURRENT> 1,255 <OTHER-ITEMS-CAPITAL-AND-LIAB> 444,801 <TOT-CAPITALIZATION-AND-LIAB> 1,516,181 <GROSS-OPERATING-REVENUE> 295,197 <INCOME-TAX-EXPENSE> 17,018 <OTHER-OPERATING-EXPENSES> 417,277 <TOTAL-OPERATING-EXPENSES> 434,295 <OPERATING-INCOME-LOSS> 46,600 <OTHER-INCOME-NET> 1,499 <INCOME-BEFORE-INTEREST-EXPEN> 48,099 <TOTAL-INTEREST-EXPENSE> 21,475 <NET-INCOME> 26,624 <PREFERRED-STOCK-DIVIDENDS> 474 <EARNINGS-AVAILABLE-FOR-COMM> 26,150 <COMMON-STOCK-DIVIDENDS> 17,939 <TOTAL-INTEREST-ON-BONDS> 17,220 <CASH-FLOW-OPERATIONS> 67,037 <EPS-PRIMARY> 1.21 <EPS-DILUTED> 1.21