LONDON—U.S. shale companies are churning out crude oil at a record pace that could overwhelm global demand and reverse the oil market’s fragile recovery, a top energy-market observer said Tuesday.

U.S. shale production is growing faster in 2018 than it did even during the boom years of $100 a barrel oil prices from 2011 to 2014, said the International Energy Agency in its closely watched monthly report. The difference this time: Oil prices are about 40% lower.

The situation is “reminiscent of the first wave of U.S. shale growth,” when a flood of American oil built up a global glut and sent prices crashing over four years ago, said the Paris-based IEA, which advises governments and corporations on energy trends.

Oil prices fell after the report’s release in Europe. Brent, the international benchmark was down 0.69% at $62.17, while U.S. prices were down 1.35% at $58.51.