Investing.com - Oil was lower Tuesday as concerns about a global supply glut continued to weigh.
U.S. crude was off 7 cents, or 0.14 %, at $49.73 at 05:30 ET. Brent lost 27 cents, or 0.51%, to $52.37.
WTI earlier touched $50 on perceptions the U.S. summer driving season had got off to a good start.
But concerns emerged about whether an extension of an OPEC-led output cut deal can reduce inventories.
OPEC and non-OPEC producers have agreed to extend output cuts of 1.8 million barrels a day for a further nine months.
Increased U.S. drilling activity could undermine the potential impact of the production curbs.