Oil prices fell sank on Thursday, with expectations building that OPEC could wind down the output deal in place since the start of 2017 due to supply concerns out of Venezuela and Iran.
A surprise build up in crude oil inventories in the United States also weighed on prices, driving the spread between Brent crude and U.S. West Texas Intermediate (WTI) close to its widest in three years.
WTI crude futures ended Thursday's session down $1.13, or 1.6 percent, at $70.71 a barrel. International benchmark Brent futures were down 93 cents, or 1.2 percent, at $78.87 per barrel by 2:24 p.m. ET.
The Organization of Petroleum Exporting Countries may decide in June to lift output to make up for reduced supply from Iran and Venezuela and in response to concerns from Washington about a rally in oil prices, OPEC and oil industry sources told Reuters.