Oil prices fell about 4 percent on Tuesday, with US crude plunging to its lowest in over a year, caught up in Wall Street's broader selloff fed by growing concerns about slowing global growth.
US West Texas Intermediate (WTI) crude futures were at $54.72 per barrel, down $2.48, or 4.3 percent by 11:14 a.m. EST (1614 GMT). The contract fell as much as 6.2 percent earlier in the session to $53.63 a barrel, the lowest since October 2017.
So far in the session, more than 585,000 U.S. futures contracts had changed hands, exceeding the daily average over the last 10 months.
Brent crude futures were $2.72, or 4.1 percent, lower at $64.07 a barrel. The international benchmark fell as much as 5.1 percent to $63.36, the lowest since early March.
Tuesday's drop extended a slide that has been largely unimpeded since early October. WTI prices are about 30 percent lower from near four-year peaks hit in early October, weighed down by surging supply and the selloff in risk assets worldwide.
Brent crude has lost 26 percent in the same period.
"For the time being it's more about risk," said Jim Ritterbusch, president of Ritterbusch and Associates.
"When the stock market comes off 8 or 9 percent, it tends to conjure up images of a weak global economy and that feeds into expectations of weaker than expected oil demand."
The S&P 500 hit a three-week low on Tuesday as weak results and forecasts from big retailers fanned worries about holiday season sales, while tech stocks continued to slide on concerns about iPhone sales.
Global stock markets have suffered a shakeout in the past two months, pressured by worries of a peak in corporate earnings growth, rising borrowing costs, slowing global economic momentum and international trade tensions.
Amid the uncertainty, financial traders have become wary of oil markets, seeing further downside risk to prices from the growth in US shale production as well as the deteriorating economic outlook.
Expectations for a ninth straight week of US crude inventory increases also weighed on prices. Seven analysts polled ahead of data from the American Petroleum Institute (APE), an industry group, estimated that crude stocks rose about 2.1 million barrels last week.
The API release is scheduled for 4:30 p.m. EST (2130 GMT), followed by government data on Wednesday morning.
US crude production has soared almost 25 percent this year, to a record 11.7 million barrels per day (bpd).
The Organization of the Petroleum Exporting Countries is pushing for a supply cut of 1 million to 1.4 million bpd when it meets on Dec. 6.
The OPEC envoy for the United Arab Emirates said it was very likely the group would reduce its output but the exact level had yet to be decided.
The International Energy Agency (IEA), however, warned OPEC and other producers of the "negative implications" of supply cuts, with many analysts fearing a spike in crude prices could erode consumption.
"We are entering an unprecedented period of uncertainty in oil markets," IEA Executive Director Fatih Birol told a conference in Norway on Monday.
Portfolio managers have sold the equivalent of 553 million barrels of crude and fuels in the last seven weeks, the largest reduction over a comparable period since at least 2013.Funds now hold a net long position of just 547 million barrels, less than half the recent peak of 1.1 billion at the end of September, and down from a record 1.484 billion in January.