(Reuters) -Canada-based crude pipeline operator Enbridge said on Tuesday it will reduce its workforce by 650 jobs, or 5%, in a bid to cut costs. Enbridge operates North America's biggest oil pipeline network, the Mainline, which moves Canadian crude from Alberta to U.S. and eastern Canadian refineries, as well as the continent's largest natural gas utility. In September, the company surprised investors, saying it would acquire three U.S. gas utility companies from Dominion Energy for $14 billion.