EXHIBIT (11) NORTHWEST NATURAL GAS COMPANY Statement Re: Computation of Per Share Earnings (Thousands, except per share amounts) (Unaudited) 12 Months Ended December 31, --------------------------------------------------- 2001 2000 1999 --------------------------------------------------- Earnings Applicable to Common Stock $ 47,786 $ 47,768 $ 42,781 Debenture Interest Less Taxes 370 389 415 ------------- ------------ ----------- Net Income Available for Diluted Common Stock $ 48,156 $ 48,157 $ 43,196 ============= ============ =========== Average Common Shares Outstanding 25,159 25,183 24,976 Stock Options 32 13 21 Convertible Debentures 421 442 471 ------------- ------------ ----------- Diluted Common Shares 25,612 25,638 25,468 ============= ============ =========== Diluted Earnings per Share of Common Stock $ 1.88 $ 1.88 $ 1.70 ============= ============ ===========