Oil prices have dropped as traders anticipate higher supplies rates due to the restart of the Keystone pipeline between Canada and the US, as well as doubts over the possible extension of the oil curb agreement.

Brent futures LCOc1 slipped 17¢ to $63.67 a barrel, while the US West Texas Intermediate (WTI) futures CLc1 fell 33¢ to $57.78 per barrel, reported Reuters.

"US WTI climbed to $59.05 a barrel last week after crude supplies to the US from Canada via the Keystone pipeline were stopped following an oil spill."

US WTI climbed to $59.05 a barrel last week after crude supplies to the US from Canada via the Keystone pipeline were stopped following an oil spill.

However, the pipeline’s owner TransCanada announced the re-commencement of supply through the 590,000 barrel pipeline at a reduced rate this week, following US regulatory approval.

In addition, global uncertainty over Russia’s commitment to join the efforts of other major oil producers to extend the ongoing crude production curbs beyond next March has put additional pressure on oil markets.

Most of the members of the Organization of the Petroleum Exporting Countries (OPEC) and other key producers are scheduled to meet this week to discuss a possible extension, which would seem them continue to withhold output beyond March next year.

OPEC and the deal’s other participants have been restricting oil production by 1.8 million barrels per day (bpd) since last January in an attempt to rebalance the oil market.