West Fraser saw its full year results reduce to C$58m from C$275m a year ago.
The Canadian timber producer said it ended a challenging year with a difficult quarter as markets continued to be unsettled.
Sales in 2011 totalled C$2.7bn, similar to the C$2.8bn recorded in 2010.
Lumber operations generated an operating loss of C$30m in the fourth quarter, reflecting weaker prices for lower-grade SPF lumber and wider dimension southern yellow pine lumber, as well as reduced shipments.
“We are approaching 2012 with conservatism and caution in light of ongoing economic uncertainty in our key markets and the continuing volatility of the Canadian dollar,” it said.
