EXHIBIT 12 NORTHWEST NATURAL GAS COMPANY Computation of Ratio of Earnings to Fixed Charges January 1, 1994 - March 31, 1999 (Thousands, except ratio of earnings to fixed charges) (Unaudited) Twelve Months Ended Year Ended December 31, March 31, ----------------------------------------------------------------------- 1994 1995 1996 1997 1998 1999 ------------------------------------------------------------------------------------- Fixed Charges, as defined: Interest on Long- Term Debt $21,921 $23,141 $23,176 $24,918 $27,567 $27,612 Other Interest 2,473 2,252 3,448 4,500 4,902 4,387 Amortization of Debt Discount and Expense 850 882 865 730 714 725 Interest Portion of Rentals 1,697 1,764 1,798 2,111 1,986 1,986 ------- ------- ------- ------- ------- ------- Total Fixed Charges, as defined $26,941 $28,039 $29,287 $32,259 $35,169 $34,710 ======= ======= ======= ======= ======= ======= Earnings, as defined: Net Income $35,461 $38,065 $46,793 $43,059 $27,301 $28,158 Taxes on Income 20,473 22,120 27,347 21,106 12,254 15,582 Fixed Charges, as above 26,941 28,039 29,287 32,259 35,169 34,710 ------- ------- ------- ------- ------- ------- Total Earnings, as defined $82,875 $88,224 $103,427 $96,424 $74,724 $78,450 ======= ======= ======= ======= ======= ======= Ratio of Earnings to Fixed Charges 3.08 3.15 3.53 2.99 2.12 2.26 ======= ======= ======= ======= ======= =======