The Globe and Mail reports in its Wednesday, June 6, edition that Enbridge has scrapped changes aimed at curbing overbooking of capacity on its mainline pipeline after shippers balked at the proposed new rules. The Globe's Jeff Lewis writes that the interim measures were designed to ease chronic congestion on Enbridge's mainline transportation system that has played a role in the deep discounting of Canadian crude prices. The mainline carries the bulk of Canadian oil exports to the United States. Enbridge made the hasty retreat after a backlash from shippers against the new rules, which would have involved a major overhaul to the way producers and other players reserve space on the Alberta-to-Wisconsin network. Prices for oil-sands-derived crude rose sharply, reflecting relief at Enbridge's reversal. The discount on heavy Western Canadian Select oil nearly halved against U.S. benchmark West Texas Intermediate crude and on Tuesday fetched $14.50 (U.S.) under WTI. Still, the sudden turnabout by Enbridge is a window into long-running attempts by it to relieve bottlenecks on the 2.85-million-barrel-a-day mainline that have weighed heavily on prices for the extra-heavy crude.