The two biggest customers on Enbridge Inc's newly reversed pipeline to carry Western Canadian oil from Sarnia, Ontario, to Montreal want to meet Canada's energy regulator to find out why the pipeline's opening has been delayed by months. Valero Energy Corp and Suncor Energy Inc, each of which owns of two refineries in the province of Quebec, said in separate letters posted on the National Energy Board's website that the delay in approving the startup of the 300,000 barrel per day Line 9 pipeline is pushing up their costs and harming their operations.