European Union leaders are set to urge faster integration of the bloc’s power and natural-gas markets to lower energy prices as the US shale-gas revolution widens the EU’s cost gap with its largest trading partner. The 27-nation EU must accelerate efforts to implement energy legislation aimed at breaking down national barriers by 2014 and develop interconnections to end the isolation of some member states from networks by 2015, according to a new draft of conclusions for a leaders’ summit in Brussels Wednesday. The summit initiative comes after a record drop in private investment in Europe and the biggest-ever slump in the EU carbon market, designed to cut pollution and stimulate a shift to cleaner fuels. “The EU’s energy policy must ensure security of supply for households and companies at affordable and competitive prices and costs, in a safe and sustainable manner,” according to the conclusions obtained by Bloomberg.