New York

THE shale oil boom that pushed US crude production to the highest level in four decades is grinding to a halt.

Output from the prolific tight-rock formations such as North Dakota's Bakken shale will decline 57,000 barrels a day in May, the Energy Information Administration (EIA) said on Monday. It's the first time the agency has forecast a drop in output since it began issuing a monthly drilling productivity report in 2013.