World oil prices dropped today as investors locked in profits following a six-day rally, with a rise in OPEC's output in March also adding to downward pressure, analysts said.
Brent North Sea crude for June delivery fell 38 cents to $63.60 a barrel in London deals. US benchmark West Texas Intermediate for delivery in May sank 42 cents to $56.68 a barrel.
Analysts said that after a sustained increase in both the WTI and Brent over the past week, traders are selling and this has led to the downward pressure in prices we see today.
Prices rose for the sixth day in a row yesterday - with WTI hitting its highest level since December - on news that US shale output, which has contributed to a global supply glut, may be on the cusp of easing.
But they said the oversupply was unlikely to end soon due to strong production levels by the Organisation of the Petroleum Exporting Countries (OPEC).
The 12-member OPEC, which pumps around a third of the world's oil, saw its production in March rise by 810,000 barrels per day to average 30.79 mbpd.
Crude prices collapsed over 50% between June and January due to the oversupply and weak demand.