Oil and natural gas company Pogo Producing ( PPP) agreed to acquire Northrock Resources, a Canadian unit of Unocal ( UCL), for $1.8 billion in cash. The deal will increase Pogo's total proven oil and gas reserves by 45%. In a press release Monday, Pogo said the purchase will add to its earnings, cash flow, production and reserves in 2006 and beyond. Pogo, based in Houston, will acquire estimated proven reserves totaling 644 billion cubic feet of natural gas equivalent. Northrock's activities are concentrated in Saskatchewan and Alberta, with added exploration areas in Canada's Northwest Territories, British Columbia and the Alberta foothills. The company plans to finance the Northrock acquisition with its cash on hand, proceeds related to international asset sales, excess capacity under its existing revolving credit facility and capital market transactions. Pogo also plans to continue its stock repurchase program. Shares of Pogo close Friday at $54.78.