Canadian Mackenzie gas pipeline on hold CALGARY, Alberta, April 6 (UPI) -- A decision to pull back from the Mackenzie natural gas pipeline from Alberta would strike a blow to provincial economies, an official said. The National Energy Board in Canada issued a certificate for the construction of the Mackenzie pipeline. The pipeline would run 743 miles from the Beaufort Sea to northwestern Alberta. It's designed to carry more than 1 billion cubic feet of natural gas per day. Project partners -- Imperial Oil Ltd., Exxon Mobil and Royal Dutch Shell -- said the low cost of natural gas meant the project was on hold, the Calgary Herald reports. The project's critics questioned the viability of the pipeline given the abundance of shale gas in the United States. Northwest Territories Premier Bob McLead said the region is out billions of dollars in revenue because of the decision. "This has a significant impact for the Beaufort part of the Northwest Territories, where there have been a lot of businesses that have invested in equipment and so on in anticipation of the pipeline," he was quoted by the Herald as saying. The pipeline could carry enough natural gas to meet the energy demands of more than 60 percent of all Canadians.