Suncor and Shell urge Canadian regulator to review contentious Enbridge pipeline plan

CALGARY, Alberta (Reuters) - Two major oil companies have asked Canada's energy regulator to urgently review Enbridge Inc's proposal to switch to fixed contracts on its Mainline pipeline system, arguing the changes would be an abuse of Enbridge's market power.Suncor Energy , Canada's second-largest oil producer, and Shell Canada Ltd, a subsidiary of Royal Dutch Shell wrote to the National Energy Board on Friday opposing Enbridge's plans.They join MEG Energy and the Explorers and Producers..