<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 March 31, 1999 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-31-1999 <PERIOD-END> MAR-31-1999 <PERIOD-TYPE> 3-MOS <BOOK-VALUE> PER-BOOK <TOTAL-NET-UTILITY-PLANT> 1,017,467 <OTHER-PROPERTY-AND-INVEST> 13,919 <TOTAL-CURRENT-ASSETS> 305,435 <TOTAL-DEFERRED-CHARGES> 265,597 <OTHER-ASSETS> 173,056 <TOTAL-ASSETS> 1,775,474 <COMMON> 43,081 <CAPITAL-SURPLUS-PAID-IN> 112,210 <RETAINED-EARNINGS> 306,645 <TOTAL-COMMON-STOCKHOLDERS-EQ> 461,936 <PREFERRED-MANDATORY> 11,350 <PREFERRED> 0 <LONG-TERM-DEBT-NET> 384,555 <SHORT-TERM-NOTES> 7,825 <LONG-TERM-NOTES-PAYABLE> 0 <COMMERCIAL-PAPER-OBLIGATIONS> 0 <LONG-TERM-DEBT-CURRENT-PORT> 46,178 <PREFERRED-STOCK-CURRENT> 820 <CAPITAL-LEASE-OBLIGATIONS> 10,795 <LEASES-CURRENT> 1,258 <OTHER-ITEMS-CAPITAL-AND-LIAB> 850,757 <TOT-CAPITALIZATION-AND-LIAB> 1,775,474 <GROSS-OPERATING-REVENUE> 269,669 <INCOME-TAX-EXPENSE> 15,348 <OTHER-OPERATING-EXPENSES> 222,872 <TOTAL-OPERATING-EXPENSES> 238,220 <OPERATING-INCOME-LOSS> 31,449 <OTHER-INCOME-NET> 609 <INCOME-BEFORE-INTEREST-EXPEN> 32,058 <TOTAL-INTEREST-EXPENSE> 10,579 <NET-INCOME> 21,479 <PREFERRED-STOCK-DIVIDENDS> 222 <EARNINGS-AVAILABLE-FOR-COMM> 21,257 <COMMON-STOCK-DIVIDENDS> 8,954 <TOTAL-INTEREST-ON-BONDS> 8,578 <CASH-FLOW-OPERATIONS> 35,646 <EPS-PRIMARY> .99 <EPS-DILUTED> .99