Weyerhaeuser Co. plans to sell its Warrenton mill to Hampton Affiliates, a family-owned forest products company. The purchase and sale agreement, announced Monday, will result in the lay offs of 94 workers, in addition to 46 employees indefinitely laid off in March. The sale will likely be completed in January 2010, when Hampton plans to begin upgrades to the mill, according to the Portland-based company's press release. Weyerhaeuser, based in Federal Way, Wash., acquired the mill, which produces wide-dimension Hemlock lumber, in 2002, said Greg Miller, a spokesman. The company, the largest private landowner in Oregon, owns about 900,000 acres in the state and still has seven manufacturing facilities, specializing in Douglas Fir and engineered wood products. Weyerhaeuser plans to concentrate its operations on Douglas fir products, Miller said. "We believe we have a competitive advantage in Douglas fir," Miller said. "It's a win-win.