Canadian regulators conducting an environmental review of Enbridge Inc.'s (ENB, ENB.T) Northern Gateway pipeline have been told they will have a limited time period to finish their work, as compelled by a new law that kicked in just a few weeks ago.

Canada's Environment Minister, Peter Kent, is set to inform regulators exactly how much more time regulators will have, said a letter dated July 6 and reviewed by Dow Jones Newswires. Also, regulators were told their final report should stick to conclusions and recommendations that relate strictly to "environmental effects."

The Northern Gateway envisions sending 525,000 barrels of oil a day from Alberta to the British Columbia port of Kitimat, where tankers would send it to China and other countries in Asia. Environmental groups and some native groups oppose its construction due to the risk of spills from the pipeline and tankers. But Canada's federal government says getting pipelines built to the west coast is strategically important for the country's energy industry, which currently relies on exports to the U.S.

As part of federal 2012 budget, Canada's Conservative government amended environmental and regulatory laws in which reviews of major projects would be limited to 24 months. Meanwhile, regular inter-provincial pipeline reviews, as conducted by the National Energy Board, would be limited to 18 months. The budget law implementing these changes kicked in on June 29.

The current hearing schedule is expected to last until next spring, with a decision on the project made later that year. If approved, the six-billion-Canadian-dollar (US$5.96 billion), 730-mile pipeline could start operations by 2017.

At the time of budget, Conservative government ministers said the new rules would apply to the Gateway project, even though hearings into the controversial pipeline had already commenced back in January. The ministers, though, did not elaborate.

A spokesman for Mr. Kent said the new timeline for the Gateway review would be made public "in due course."

Write to Paul Vieira at paul.vieira@dowjones.com. Write to Edward Welsch at edward.welsch@dowjones.com.