Investing.com - Oil prices edged lower for the third day in a row in North American trading on Tuesday, as investors looked ahead to weekly data from the U.S. on stockpiles of crude and refined products.
Industry group the American Petroleum Institute is due to release its weekly report at 4:30PM ET (20:30GMT) later on Tuesday.
Official data from the Energy Information Administration will be released Wednesday, amid forecasts for an oil-stock drop of around 3.4 million barrels.
The U.S. West Texas Intermediate crude July contract was at $47.30 a barrel by 8:30AM ET (12300GMT), down 10 cents, or around 0.2%.
Elsewhere, Brent oil for August delivery on the ICE Futures Exchange in London dipped 16 cents to $49.31 a barrel.
Oil prices finished lower for the second straight session on Monday as a political rift between Qatar and several Arab states, including Saudi Arabia, sparked concern that it would undermine an OPEC-led push to tighten the market.
With oil production of about 620,000 barrels per day, Qatar's crude output ranks as one of the smallest among OPEC producers, but tension within the cartel could weaken an agreement to hold back production in order to prop up prices.
Last month, OPEC and some non-OPEC producers extended a deal to cut 1.8 million barrels per day in supply until March 2018.
Concerns that the ongoing rebound in U.S. shale production could derail efforts by other major producers to rebalance global oil supply and demand remained in focus.
The U.S. rig count rose for the 20th week in a row to the highest level since April 2015 last week, implying that further gains in domestic production are ahead.
Elsewhere on Nymex, gasoline futures for July shed 0.4 cents, or about 0.3%, to $1.533 a gallon, while July heating oil slipped 0.4 cents to $1.454 a gallon.
Natural gas futures for July delivery jumped 6.0 cents to $3.042 per million British thermal units.