Oil prices fell 2 percent in Asian trade on Wednesday, as a stronger-than-expected build in U.S. crude oil stocks and weaker U.S. manufacturing data fueled a rout in prices that started in the previous session.
Brent and U.S. crude finished around 8 percent lower on Tuesday to end a 25 percent three-session surge, the largest three-day gain since 1990.
That came after oil prices dropped to their lowest in six-and-a-half years last week.
This roller-coaster volatility could continue especially if there are similar wild swings in the equity markets, said Ric Spooner, chief market analyst at Sydney's CMC Markets.
"Any change in sentiment tends to be amplified. Any change in direction in the oil markets has the potential to be risk driven by what's going on in the equity markets," he said.
U.S. stocks fell nearly 3 percent on Wall Street on Tuesday, with all three major U.S. equity indexes in negative territory for the year so far.
Brent crude LCOc1 for October delivery had dropped 84 cents to $48.72 a barrel, or 1.7 percent, as of 0655 GMT, after falling $4.59, or 8.48 percent, in the previous session.
U.S. crude CLc1 for October delivery declined 98 cents or 2 percent, to $44.43 a barrel, after ending down $3.79, or 7.7 percent, in the previous session.
Oil prices retreated after data from industry group the American Petroleum Institute on Tuesday showed U.S. crude stocks surged by 7.6 million barrels to 456.9 million in the week to Aug. 28. Analysts in a Reuters poll expected just a 32,000 barrel gain.
Official inventory data will be released by the U.S. Energy Information Administration later on Wednesday.
Weaker-than-expected U.S. manufacturing data from the Institute for Supply Management (ISM), which showed growth in August slowed to its lowest level since May 2013, also weighed on oil prices in the Asia timezone.
Upcoming U.S. data, including oil stocks, factory orders and employment figures, will be important in giving oil markets direction, Spooner said.
Prices are expected to hold at current levels until U.S. crude data is released, when they are expected to fall if oil inventories are higher, Singapore's Phillip Futures said in a note on Wednesday.
"We expect prices to find support at $42.18 (for U.S. crude) and $46.84 (for Brent)."
CMC's Spooner said prices were expected to end the week down, but should be above last week's lows.
Crude prices have fallen too far, too fast and should recover gradually over the next year, with Brent averaging $62.30 a barrel in 2016 and U.S. crude $57 a barrel, a Reuters poll of analysts showed on Tuesday.
(Reporting by Keith Wallis; Editing by Joseph Radford and Subhranshu Sahu)