TORONTO (AP) — Canada's Federal Court of Appeal on Thursday halted the contentious Trans Mountain pipeline expansion that would nearly triple the flow of oil from the Alberta oil sands to the Pacific Coast — a setback that comes just as the government is buying the project.

The court ordered the country's National Energy Board to redo its review of the pipeline, saying the original study was flawed and lacked adequate consultations with First Nations peoples.

Prime Minister Justin Trudeau's government approved Trans Mountain in 2016 and was so determined to see it built that it announced plans...