CALGARY, Alberta, Oct 4 (Reuters) - Canada on Monday formally invoked a 1977 treaty with the United States to request negotiations over Enbridge Inc's (ENB.TO) Line 5 oil pipeline, which the state of Michigan has ordered to shut down over concerns it could leak into the Great Lakes.
Gordon Giffin, legal counsel for the Canadian government, filed a letter to the federal court dealing with the legal dispute between Enbridge and Michigan, informing the judge of the move.
Canada's foreign ministry did not immediately respond to a request for comment.
Reporting by Nia Williams in Calgary, Sebastien Malo in New York and Steve Scherer in Ottawa
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