EXHIBIT 11

NORTHWEST NATURAL GAS COMPANY

Statement Re: Computation of Per Share Earnings

(Thousands, except per share amounts)

(Unaudited)

	Three Months Ended June 30,					Six Months Ended June 30,
	2005		2004			2005		2004
Net income (loss)	$	1,140	$	(716	)	$	41,027	$	31,896
Debenture interest less taxes		47		61			94		123
Net income (loss) - diluted	$	1,187	$	(655	)	$	41,121	$	32,019
Average common shares outstanding - basic		27,555		27,257			27,567		26,615
Stock options		66		45			61		52
Convertible debentures		213		280			213		280
Average common shares outstanding - diluted		27,834		27,582			27,841		26,947
Earnings (loss) per share of common stock - basic	$	0.04	$	(0.03	)	$	1.49	$	1.20
Earnings (loss) per share of common stock - diluted	$	0.04	$	(0.03	)	$	1.48	$	1.19

No shares were excluded from the calculation of diluted earnings per share for the three- and six-month periods ended June 30, 2005. For the three- and six-month periods ended June 30, 2004, 184,800 shares were excluded from the calculation of diluted earnings per share because the effect would have been antidilutive.