The United States will remain the world’s top source of oil supply growth up to 2020, even after the recent collapse in prices, the International Energy Agency said, defying expectations of a more dramatic slowdown in shale growth. The agency also said in its Medium Term Oil Market report that oil prices LCOc1, which slid from $115 a barrel in June to a near six-year low close to $45 in January, would likely stabilize at levels substantially below the highs of the last three years. Oil prices deepened their decline after the Organization of the Petroleum Exporting Countries in November shifted strategy and declined to cut its own output, choosing to retain market share against rival supply sources such as U.S. shale oil. “The market rebalancing will likely occur relatively swiftly but will be comparatively limited in scope,” the IEA said. “The price correction will cause the North American supply ‘party’ to mark a pause; it will not bring it to an end.”