The price of oil fell below US$103 barrel Wednesday as traders expected the Energy Department to report an increase in U.S. supplies.
Benchmark West Texas Intermediate crude for July delivery dropped $1.39 to close at US$102.72 a barrel on the New York Mercantile Exchange.
Brent crude, a benchmark for international oils, fell 21 cents to US$109.81 on the ICE exchange in London.
Traders were waiting for the latest information on U.S. supplies of crude and refined products.
Data for the week ended May 23 is expected to show an increase of one million barrels in crude oil stocks and a decline of 200,000 barrels in gasoline stocks, according to a survey of analysts by Platts, the energy information arm of McGraw-Hill Cos.
In other energy futures trading on the Nymex, wholesale gasoline rose one cent to US$3.01 a U.S. gallon (3.79 litres), heating oil fell one cent to US$2.93 a gallon and natural gas added 11 cents to US$4.62 per 1,000 cubic feet.