LONDON (Reuters) – Oil prices slipped on Thursday as U.S. fuel inventories rose despite efforts by OPEC to cut production  Brent crude oil was down 20 cents at $56.74 a barrel by 0840 GMT. U.S. light crude was 35 cents lower at $50.95. Both benchmarks have risen more than 20 percent from their lows in June as world oil markets tightened.  The Organization of the Petroleum Exporting Countries and other producers including Russia agreed last year to reduce output by 1.8 million barrels per day (bpd) to prop up prices and the cuts, from January, have helped drain inventories.

The OPEC-led deal helped lift oil from the $30 to $40 per barrel range in late 2016/early 2017. But traders say supplies remain ample despite these cuts, thanks in large part to surging U.S. production.  OPEC is widely expected to extend its cuts beyond the current expiry date of end-March 2018.  “There is little doubt that leading producers have re-committed to do whatever it takes to underpin the market,” the International Energy Agency said in a report on Thursday.  “For next year, the crude and product markets look broadly balanced, assuming OPEC holds output steady at around current levels,” the IEA added.  Many analysts expect Brent to stay between $50 and $60 a barrel as long as global markets stay balanced. But risks remain, including the possibility of tension in the Middle East.