U.S. crude settled below $44 for the first time since March on Friday, pressured by tumbling gasoline prices as the approaching end of the U.S. summer driving season suggested a growing surplus in fuel supply.
The U.S. benchmark West Texas Intermediate settled down 79 cents at $43.87 a barrel, near a six-year closing low of $43.46 reached in March.
Crude oil futures plumbed multi-month lows Friday and racked up a sixth straight week of losses.
Also weighing on prices was the latest rig count from oilfield services firm Baker Hughes, which showed U.S. energy firms added 6 oil rigs this week, continuing a recent trend of increases, even after U.S. crude oil prices plunged 25 percent from a recent high in June.
The rig count gain this week was the third increase in a row, the longest winning streak since September 2014, bringing the total rig count up to 670, the highest since early May.
The dollar rose to a 3½ month high against a basket of currencies after strong U.S. jobs growth in July, putting pressure on oil and other commodities denominated in the greenback.