A legal battle between Canadian company Enbridge Inc. and the U.S. state of Michigan over Enbridge’s Line 5 oil pipeline will be heard in federal court, a judge ruled on Nov. 16, dismissing Michigan’s motion to have the case sent back to state court.

Line 5 ships 540,000 bbl/d of crude and refined products from Superior, Wisconsin, to Sarnia, Ontario, via the Straits of Mackinac in the Great Lakes.

Michigan ordered the pipeline to shut down by May over concerns an underwater section could leak into the Great Lakes, an order that Enbridge has ignored.

Last month the Canadian government, which intervened in the court case in support of Enbridge, invoked a 1977 pipeline treaty with the U.S. to trigger negotiations between Ottawa and Washington over the pipeline’s fate.

Calgary, Alberta-based Enbridge welcomed the decision from U.S. District Judge Janet Neff in the Western District of Michigan.

“Enbridge is pleased with the decision and agrees that this case belongs in federal court as we've asserted all along,” Enbridge spokesman Ryan Duffy said in an email. “This is both a federal and international law issue and the federal court will now handle the case.”

Michigan is reviewing the decision and considering its next steps, said Lynsey Mukomel, spokeswoman for the state attorney general’s department.

The decision to keep the case in federal court is a plus for Enbridge, which is arguing the state of Michigan has no authority to shut down the pipeline, said Kristen van de Biezenbos, a law professor at the University of Calgary.

“Now that Canada has invoked the treaty, the fact that the issues transcend Michigan state law is pretty clear,” van de Biezenbos said.

Enbridge and the Michigan attorney general’s office did not immediately respond to requests for comment.