Oil prices fell on Thursday as traders booked profits following recent gains and weighed up the impact of a weakening dollar on crude futures against disappointing Chinese economic data.
Prices had risen in recent days thanks to a weaker dollar and signs that a global supply glut was easing.
In late London trading, Brent North Sea crude for delivery in June eased seven cents to stand at $66.74 a barrel.
US benchmark West Texas Intermediate for June delivery fell 90 cents to $59.60 a barrel compared with Wednesday's close.
The euro rallied to three-month peaks against the dollar Thursday on bright eurozone economic growth data and disappointing US numbers, aiding demand for commodities such as oil priced in the US currency.
Crude futures won support also from official data Wednesday showing that crude US stockpiles dropped 2.2 million barrels last week.
It was the second straight week of declines, and was much larger than the 250,000-barrel decrease expected by analysts.
However, the International Energy Agency (IEA) has said this week that a global supply glut blamed for the recent plunge in oil prices remains as producers raise their output to make up for a cut in US shale production.
Meanwhile, "the global demand situation for oil is considerably weaker" following this week's poorly-received economic data out of China, according to Michael McCarthy, a strategist for CMC Markets trading group.