nd cut into sales by the OPEC oil cartel, for decades the dominant power in world energy markets.Last week OPEC, which accounted for around 35 percent of world supply in 2012, raised its expectation of production growth by non-OPEC suppliers in 2013 by 11 percent to 1.0 million barrels a day, with the growth mainly coming from North America.As in the previous year, US oil supply in 2013 is expect