The Canada Energy Regulator says exports of crude oil by rail from Canada fell slightly in August to 310,000 barrels per day from 313,000 bpd in July.

The August number is up 35 per cent from 230,000 bpd reported in August of 2018 but still well below the record high of 354,000 bpd set last December.

The small change in crude-by-rail shipments came despite a threat by Imperial Oil Ltd. CEO Rich Kruger to throttle back the company's rail movements in August and September to protest the ongoing Alberta oil production curtailment program.

He says the program damages the economic case for crude-by-rail by artificially lowering the difference in oil prices between Alberta and the end market on the U.S. Gulf Coast.

Imperial reported moving 80,000 bpd by rail in June. It co-owns an oil shipping rail terminal at Edmonton with capacity to load 210,000 barrels of crude per day.

Alberta has gradually eased the curtailment program designed to better align production with tight pipeline capacity from an initial withholding of about 325,000 bpd last January to 125,000 bpd in September.