Enbridge Inc, Canada's largest pipeline company, reported a slightly lower-than-expected profit as the company's liquids pipeline business was hit by a massive wildfire in Fort McMurray, Alberta.

Chief Executive Al Monaco said on Friday the company and its partners remained committed to its plan to build the Northern Gateway pipeline, which would carry crude from Alberta's oil sands to a deepwater port on British Columbia's coast.

Enbridge's Northern Gateway pipeline faced a setback in June, when a Canadian court overturned the approval for the pipeline, imposing further delays on the $7.9 billion project.

"The Aboriginal equity partners and our commercial project proponents remain fully committed to building this critical Canadian infrastructure project ...," CEO Monaco said in a statement.

Enbridge said in May it would reduce its own stake in the project to boost potential ownership by First Nation and Metis partners from 10 per cent to 33 per cent, and pledged to give the aboriginal owners an equal voice on project governance.

Enbridge's second-quarter earnings were hit because its pipeline network faced disruption in May, when a massive wildfire that struck northern Alberta and forced the evacuation of the oil sands hub of Fort McMurray.

Several oil producers and pipeline operators shutdown in the region for weeks, at one point cutting Canada's crude output by more than a million barrels a day.

All of Enbridge's pipelines in and out of its Cheecham terminal some 50 km (31 miles) south of the fire-ravaged city were shut down, affecting some 900,000 barrels per day of volume on its system.

Oil sands production substantially came back on line by the end of June, Enbridge said on Friday. Throughput on Enbridge's liquids mainline system and overall system utilization are expected to be return to normal levels in the current quarter.

Earnings from continuing operations attributable to the company's shareholders fell to $301 million, or 33 cents per share, in the second quarter ended June 30, from $577 million, or 67 cents per share, a year earlier.

Excluding items, the company earned 50 cents per share, missing the average analyst estimate of 51 cents, according to Thomson Reuters.