EXHIBIT 11 NORTHWEST NATURAL GAS COMPANY Statement re: Computation of Per Share Earnings (Thousands, except per share amounts) (Unaudited) Three Months Ended March 31, ------------------ 1996 1995 ------- ------- Earnings Applicable to Common Stock $22,665 $18,317 Preference Stock Dividends - 25 Debenture Interest Less Taxes 132 134 ------- ------- Net Income Available for Fully-Diluted Common Stock $22,797 $18,476 ======= ======= Average Common Shares Outstanding 14,850 13,916 Stock Options 12 9 Convertible Preference Stock - 70 Convertible Debentures 399 404 ------- ------- Fully-Diluted Common Shares 15,261 14,399 ======= ======= Fully-Diluted Earnings Per Share of Common Stock $1.49 $1.28 ======= ======= 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.