A long work stoppage could cause significant supply chain disruptions.
DETROIT — Canada’s two largest railroads are starting to shut down their shipping networks as a labor dispute with the Teamsters union threatens to cause lockouts or strikes that would disrupt cross-border trade with the U.S.
Both the Canadian Pacific Kansas City and Canadian National railroads, which haul millions of tons of freight across the border, have stopped taking certain shipments of hazardous materials and refrigerated products.
Both are threatening to lock out Teamsters Canada workers starting Thursday if deals are not reached.
On Tuesday, CPKC will stop all shipments that start in Canada and all shipments originating in the U.S. that are headed for Canada, the railroad said Saturday.
The Canadian Press reported that on Friday, Canadian National barred container imports from U.S. partner railroads.
Jeff Windau, industrials analyst for Edward Jones & Co., said his firm expects work …