EXHIBIT 11

NORTHWEST NATURAL GAS COMPANY

Statement Re: Computation of Per Share Earnings

(Thousands, except per share amounts)

(Unaudited)

	Three Months Ended Sept. 30,						Nine Months Ended Sept. 30,
	2005			2004			2005		2004
Net income	$	(8,671	)	$	(8,285	)	$	32,356	$	23,611
Debenture interest less taxes		—			60			—		179
Net income - diluted	$	(8,671	)	$	(8,225	)	$	32,356	$	23,790
Average common shares outstanding - basic		27,560			27,373			27,564		26,868
Stock options		70			43			62		47
Convertible debentures		—			272			—		272
Average common shares outstanding - diluted		27,630			27,688			27,626		27,187
Earnings per share of common stock - basic	$	(0.31	)	$	(0.30	)	$	1.17	$	0.88
Earnings per share of common stock - diluted	$	(0.31	)	$	(0.30	)	$	1.17	$	0.88

For the three- and nine-month periods ended Sept. 30, 2005, 6,000 shares were excluded from the calculation of diluted earnings per share because the effect would have been antidilutive. For the three- and nine-month periods ended Sept. 30, 2004, 202,800 shares and 18,000 shares, respectively, were excluded from the calculation of diluted earnings per share for this reason.