HUDSON'S BAY WRITEOFF MAINLY DUE TO DOME STAKE <Hudson's Bay Co> said a writeoff of 40.4 mln dlrs, or 1.39 dlrs per share, that it took in 1986 was mainly due to its investment in Dome Petroleum Ltd <DMP>. The company reported an operating profit of 33.0 mln dlrs, or 32 cts per share, for fiscal 1986, compared to an operating loss of 9,055,000 dlrs, or 1.23 dlrs per share, in the previous year. Hudson's Bay holds about four mln shares of Dome's 10 pct series one cumulative subordinate convertible preferred shares. Last March, Dome suspended payment of dividends on all preferred shares until June 1, 1987. The shares give the holder the right to convert to Dome common shares at 3.33 dlrs per share. Dome has the right to force conversion if Dome common reaches 3.885 dlrs per share. Dome is trading at 1.12 dlrs per share, down one ct, today on the Toronto Stock Exchange. Hudson's Bay also said it had an increase in 1986 in retail operating profit to 185.3 mln dlrs from 111.4 mln dlrs, but that was partially offset by an increase of 14.9 mln dlrs in interest costs and 25.3 mln dlrs in taxes. Hudson's Bay also said its Markborough properties subsidiary had an operating profit of 108.6 mln dlrs, up from 98.8 mln dlrs the year before. Profit from non-Markborough real estate was 23.5 mln dlrs in 1986, down from 27.6 mln dlrs a year ago. Operating profit from natural resources was 4.2 mln dlrs, up 1.2 mln dlrs from the prior year. Pensions costs were reduced by 34.9 mln dlrs due to an accounting change. Total debt declined during the year by 251 mln dlrs to 2.28 billion dlrs and debt to equity ratio improved to 1.8 to one from 2.1 to one.