U.S. crude closed down about 5 percent to $46.60 a barrel Tuesday, weighing on energy stocks.
Financial stress in the U.K. after the country's vote to leave the EU last month, and data from China expected in coming weeks to show weakened trade and investment contributed to nervousness over a global slowdown in growth.
"The deterioration in the global economic outlook, financial market uncertainty and ripple effects on key areas of oil demand growth are likely to exacerbate already-lackluster industrial demand growth trends," British bank Barclays said in a report.
Although WTI is down Tuesday, it is still significantly up compared to its multi-year low levels reached in February.
U.S. crude in 2016
— Reuters contributed reporting