The US International Trade Commission (ITC) has decided to uphold stringent duties on Canadian softwood lumber exports to the US.

Canadian lumber companies must now start to pay duties averaging 27% from May 23, which is widely expected to lead to more job losses and mill shutdowns.

However, the ITC ruled that the duties were not retrospective, meaning about US$760m in preliminary duties set aside by the Canadians since last year will now be refunded.

British Columbia is most affected by the ruling and the province’s government estimates that job losses could rise to 50,000 if the duties are not revoked.

Canada is continuing a legal challenge of the duties at the World Trade Organisation and at a dispute panel of the North American Free Trade Agreement.

Weyerhaeuser said the ITC decision forced US consumers to ‘bear the brunt’ in resulting higher prices. The company calls for renewed negotiations to solve the dispute.