Oil prices fell in European trade for the second session off 2019 highs on profit-taking amid concerns about global growth while the US pumps record amounts of crude.
As of 09:55 GMT, US crude fell to $56.20 a barrel, with an intraday low at $56.15, while Brent fell to $66.08 a barrel.
US crude slipped 0.1% yesterday, the first loss in six days, while Brent declined 0.1% as well off three-month highs.
Oil prices are retreating on profit-taking amid caution on lower global demand due to slower growth.
US production continues at record highs, in turn hurting efforts by OPEC and Russia to support the market.
US output rose by 2 million bpd in 2018, a 20% surge, while up 40% from mid-2016 levels.