NEB, the nation's energy regulator, published data Wednesday for March showing total crude exports of 2.85 million barrels was a monthly record for the year and 5 percent more than February figures.
NEB provided no data on export destination. Typically, nearly all of Canada's oil exports head to the United States.
More of that crude oil is headed across the border by rail as increased production strains existing pipeline capacity. In January, the Transportation Safety Board of Canada said 500 railcars delivered oil in 2009, but increased to 160,000 in 2013.
Canadian Prime Minister Stephen Harper has sought to add a layer of diversity to an energy export economy that depends almost exclusively on the United States.
Canada and Saudi Arabia were the top oil exporters to the United States for the first week of May, with a combined 4.1 million bpd sent to the U.S. market.