Oil prices fell today after rebounding 8% in the previous session, with prices pressured by concerns over a faltering global economy and worries about a glut in crude supply.
Brent crude futures dropped 80 cents, or 1.5%, to $53.67 a barrel, while US West Texas Intermediate (WTI) crude futures fell 58 cents to $45.64 a barrel, a 1.3% loss.
Prices had surged on Wednesday, tracking a spike in the US equities market after President Donald Trump's administration attempted to shore up investor confidence.
However, US stocks retreated today, dragging oil prices down with them.
Both Brent and WTI have lost more than a third of their value since the beginning of October and are heading for losses of around 20% in 2018.
Concerns about slowing global economic growth have dampened investor sentiment in riskier asset classes and pressured crude futures.
Market participants have grown worried about an oversupply of crude.
Three months ago it looked as if the global oil market would be undersupplied through the northern hemisphere winter as US sanctions removed large volumes of Iranian crude.
But other oil exporters have compensated for any shortfall, filling global inventories and depressing prices.
The Organization of the Petroleum Exporting Countries met earlier this month with other producers including Russia and agreed to reduce output by 1.2 million barrels per day (bpd), equivalent to more than 1% of global consumption.
But the cuts will not take effect until next month and oil production has been at or near record highs in the US, Russia and Saudi Arabia, with the US pumping 11.6 million bpd of crude, more than both Saudi Arabia and Russia.
Russian Energy Minister Alexander Novak said today the country will cut its output by between 3 and 5 million tonnes in the first half of 2019 as part of the deal.
It then will be able to restore it to 556 million tonnes (11.12 million barrels per day) for the whole 2019, on par with 2018, he added.
Although US sanctions have put a cap on Iran's oil sales, Tehran has said its private exporters have "no problems" selling its oil.