The Canadian government will ask the World Trade Organization for authority to retaliate against at least $4.1 billion in U.S. imports over American noncompliance with WTO rulings on softwood lumber, officials said Wednesday.

The Department of International Trade will apply Monday to the compliance panel of the trade body, which ruled last year Canadian lumber imports pose no threat to American producers. Canada argues Washington hasn't abided by the WTO's ruling and rescinded punitive import duties levied on Canadian lumber.
The unprecedented dollar figure represents the total of countervailing and antidumping duties collected since the tariffs were imposed in May 2002, after the U.S. Commerce Department ruled Canadian lumber imports were being subsidized unfairly by provincial forestry policies.
Canada appealed the duties under WTO and North American Free Trade Agreement rules, and panels from both bodies found Canadian lumber, which supplies about one-third of the U.S. market, does not threaten American mills.
Officials said the retaliatory amount is the largest Ottawa has ever requested against the United States in a trade dispute.