EXHIBIT 11 NORTHWEST NATURAL GAS COMPANY Statement Re: Computation of Per Share Earnings (Thousands, except per share amounts) (Unaudited) Three Months Nine Months Ended Ended September 30, September 30, ------------------ ---------------- 1996 1995 1996 1995 ------- ------- ------- ------- Earnings (Loss) Applicable to Common Stock $ (418) $(5,038) $27,070 $16,097 Debenture Interest Less Taxes 124 133 371 400 ------- ------- ------- ------- Net Income (Loss) Available for Fully-Diluted Common Stock $ (294) $(4,905) $27,441 $16,497 ======= ======= ======= ======= Average Common Shares Outstanding 22,435 22,141 22,351 21,688 Stock Options 31 13 27 11 Convertible Debentures 562 605 562 605 ------- ------- ------- ------- Fully-Diluted Common Shares 23,028 22,759 22,940 22,304 ======= ======= ======= ======= Fully-Diluted Earnings (Loss)Per Share of Common Stock $ (0.01)* $(0.22)* $ 1.20 $ 0.74 ======= ======= ======= ======= *Anti-dilutive 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.