Oil prices closed lower Tuesday on expectations of a 10th week of record builds in U.S. crude, although a weaker dollar limited the market's downside.
Traders and investors have forecast that crude stocks in the United States rose last week to above 452 million barrels, a Reuters poll showed. That would be the biggest domestic stockpile in at least 80 years.
The American Petroleum Institute, an industry group, will issue its weekly inventory report at 4:30 p.m. EDT (2030 GMT), two hours after the market's close and ahead of Wednesday's official data from the U.S. Energy Information Administration.
Also pressuring prices was rising output in Libya and Iran's eagerness to export more oil once it clinches a nuclear deal removing Western sanctions, traders said.
The slide in crude prices was limited by a weaker dollar that made commodities denominated in the greenback more appealing to holders of other currencies. The dollar paused on Tuesday in its march toward parity with euro, weakening almost half a percent against the single currency.
Position squaring ahead of the expiry of options in U.S. crude added volatility to the market.
"You're getting a little crazy action today because options are expiring," said Tariq Zahir, managing partner at Tyche Capital Advisors in Laurel Hollow in New York.