Oil prices fell on Thursday as the fourth weekly increase in U.S. crude inventories suggested ample supply, while Saudi-U.S. tension and falling Iranian exports lent support.
Crude futures came off one-month lows in early trading as U.S. stock markets bounced. But equities turned sharply lower in late morning trade, and the oil market fell to session lows.
U.S. West Texas Intermediate crude ended Thursday's session down $1.10, or 1.6 percent, at $68.65, after hitting a one-month low at $68.47 earlier in the session. WTI plunged 3 percent on Wednesday.
Brent crude, the global benchmark, was down 67 cents at $79.38 a barrel at 2:30 p.m. ET. It fell as low as $78.69 earlier in the day, down $8 from a nearly four-year high reached on Oct. 3.
On Wednesday, government data showed U.S. crude inventories rose 6.5 million barrels last week, the fourth straight weekly increase and almost three times what analysts had forecast.