EXHIBIT 11 NORTHWEST NATURAL GAS COMPANY Statement Re: Computation of Per Share Earnings (Thousands, except per share amounts) (Unaudited) 12 Months Ended December 31 -------------------------- 1993 1992 1991 ---- ---- ---- Earnings Applicable to Common Stock $34,159 $13,215 $11,784 Preference Stock Dividends 155 168 178 Debenture Interest Less Taxes 572 598 675 ------- ------- ------- Net Income Available for Fully-Diluted Common Stock $34,886 $13,981 $12,637 ======= ======= ======= Average Common Shares Outstanding 13,074 11,909 11,698 Stock Options 24 25 32 Convertible Preference Stock 108 116 123 Convertible Debentures 433 446 452 ------- ------ ------ Fully-Diluted Common Shares 13,639 12,496 12,305 ======= ====== ====== Fully-Diluted Earnings Per Share of Common Stock $2.56 $1.12 $1.03 ===== ===== ===== Note: Primary earnings per share are computed on a weighted daily average number of common shares outstanding each year. Outstanding stock options are common stock equivalents but are excluded from primary earnings per share computations due to immateriality.