EXHIBIT 11 NORTHWEST NATURAL GAS COMPANY Statement Re: Computation of Per Share Earnings (Thousands, except per share amounts) (Unaudited) Three Months Ended Six Months Ended June 30, June 30, ------------------ ----------------- 1996 1995 1996 1995 ------ ------ ------- ------- Earnings Applicable to Common Stock $4,823 $2,818 $27,488 $21,135 Debenture Interest Less Taxes 127 133 254 267 ------ ------ ------- ------- Net Income Available for Fully-Diluted Common Stock $4,950 $2,951 $27,742 $21,402 ====== ====== ======= ======= Average Common Shares Outstanding 14,895 14,700 14,872 14,308 Stock Options 22 9 22 9 Convertible Preference Stock - - - - Convertible Debentures 385 404 385 404 ------ ------ ------- ------- Fully-Diluted Common Shares 15,302 15,113 15,279 14,721 ====== ====== ======= ======= Fully-Diluted Earnings Per Share of Common Stock $0.32 $0.20* $1.82 $1.45 ====== ====== ======= ======= Note: Primary earnings per share are computed on the weighted daily average number of common shares outstanding each period. Outstanding stock options are common stock equivalents but are excluded from primary earnings per share computations due to immateriality. *Anti-dilutive