The United States enjoyed a record surge in oil and gas production last year, boosted by a shale energy revolution, British energy giant BP said on Wednesday. \"On the supply side, the most noticeable phenomenon remains the American shale revolution,\" said BP Chief Executive Bob Dudley in an introduction to the group\'s global outlook report. \"In 2012, the US recorded the largest oil and natural gas production increases in the world, and saw the largest gain in oil production in its history.\" American oil output increased by 1.0 million barrels per day (bpd) last year, which helped it slash net oil imports by 930,000 bpd, BP added in its Statistical Review of World Energy 2013. At the same time, gas output in the United States jumped by 4.7 percent to record the largest increase and retain its place as the world\'s top gas producer. BP added Wednesday that world energy consumption growth eased to 1.8 percent in 2012, down from 2.4 percent the previous year, as demand was hit by the global economic slowdown and increased efficiency. \"The year 2012 saw a slowdown in the growth of energy consumption globally, partly as a result of the economic slowdown but also because individuals and businesses have responded to high prices by becoming more efficient in their use of energy,\" added Dudley. \"At the same time, the review shows that the supply of energy is coming from an increasing diversity of sources as the world\'s energy market continues to adapt, innovate and evolve.\" BP said emerging economies established themselves as the main source of energy demand growth, with China and India alone accounting for almost 90 percent of the increase. \"Just twenty years ago, the emerging economies accounted for only 42 percent of global consumption; now that figure is 56 percent.\" In another key development, BP noted that global nuclear energy output suffered a record annual decline last year, tumbling by 6.9 percent due to ongoing fallout from Japan\'s Fukushima disaster in 2011. \"In Japan, where nuclear power all but disappeared after 2011\'s Fukushima accident, higher imports of fossil fuels including liquefied natural gas kept the lights on.\" Turning to crude oil, BP added that production grew last year by 1.9 million barrels per day, or 2.2 percent, despite the impact of unrest in the Middle East and North Africa region. The Organization of Petroleum Exporting Countries (OPEC) oil cartel accounted for about 75 percent of this increase, despite falling output in sanctions-hit Iran. \"For a second consecutive year, oil supply disruptions in Africa and the Middle East were offset by growth among other Middle East producers, with record oil production in Saudi Arabia, the United Arab Emirates and Qatar,\" BP said. OPEC, which pumps about 35 percent of global oil, decided last month to maintain their oil output at 30 million bpd. However, actual output runs above this target level, partly owing to strong production from cartel kingpin Saudi Arabia. Separately on Wednesday, the International Energy Agency estimated that OPEC oil supplies rose by 135,000 barrels in May to the highest level for seven months at 30.89 million bpd. OPEC continues to pump more oil despite sluggish economic growth dampening an increase in demand, according to the IEA.