Oil prices tumbled on Tuesday on concerns about the pace of economic growth in China and a stronger US dollar, as a Reuters survey showed OPEC output fell in December.
Global benchmark Brent crude prices were down 17 cents at $37.05 a barrel. US West Texas Intermediate crude slipped 7 cents to $36.69 a barrel, Reuters reported.
"It is the Chinese stock market sell-off and the strong dollar that are pressuring oil," said Tamas Varga, oil analyst at London brokerage PVM Oil Associates.
Concerns about the economy in China, the world's second-largest oil consumer, were worsened by news that national rail freight volumes logged their biggest ever annual decline in 2015.
The US dollar hit a one-month high against a basket of other currencies, weighing on oil prices as it made holding dollar-denominated commodities more expensive.
Reuters also reported on Tuesday that the Organization of Petroleum Exporting Countries pumped less oil in December compared to November, led by lower supply from Iraq following a record-breaking month in November and smaller declines elsewhere in the producer group.
OPEC is still pumping close to record amounts as Saudi Arabia and other big producers focus on market share, weighing on any recovery in oil prices from near 11-year lows.
