EXHIBIT 12 Northwest Natural Gas Company Computation of Ratio of Earnings to Fixed Charges January 1, 1991 - March 31, 1996 ($000) Twelve Months Ended ---------Year Ended December 31--------- March 31, 1991 1992 1993 1994 1995 1996 ---- ---- ---- ---- ---- ---- Fixed Charges, as defined: Interest on Long- Term Debt $21,977 $23,001 $22,578 $21,921 $23,141 $23,278 Other Interest 4,266 3,223 1,906 2,473 2,252 2,089 Amortization of Debt Discount and Expense 348 511 775 850 882 884 Interest Portion of Rentals 1,485 1,439 1,701 1,697 1,764 1,764 ------- ------- ------- ------- ------- ------- Total Fixed Charges, as defined $28,076 $28,174 $26,960 $26,941 $28,039 $28,015 ======= ======= ======= ======= ======= ======= Earnings, as defined: Net Income $14,377 $15,775 $37,647 $35,461 $38,065 $42,369 Taxes on Income 2,321 6,951 22,096 20,473 22,120 25,482 Fixed Charges, as above 28,076 28,174 26,960 26,941 28,039 28,015 ------- ------- ------- ------- ------- ------- Total Earnings, as defined $44,774 $50,900 $86,703 $82,875 $88,224 $95,866 ======= ======= ======= ======= ======= ======= Ratio of Earnings to Fixed Charges 1.59 1.81 3.22 3.08 3.15 3.42 ==== ==== ==== ==== ==== ====