Investing.com - Crude oil prices slid lower on Friday, as traders grew more cautious due to the possibility of supply disruptions caused by incoming tropical storm Nate, although sustained signs that the market is progressively rebalancing continued to support the commodity.
The U.S. West Texas Intermediate crude November contract was down 21 cents or about 0.45% at $50.56 a barrel by 3:35 a.m. ET (07:35 GMT).
Elsewhere, Brent oil for November delivery on the ICE Futures Exchange in London was down 16 cents or about 0.30% at $56.84 a barrel.
Prices retreated as traders monitored tropical storm Nate which was heading toward the Gulf of Mexico and was expected to evolve into a hurricane by the weekend.
BP (LON:BP) and Chevron (NYSE:CVX) were shutting production at all Gulf platforms on Friday, while Royal Dutch Shell (LON:RDSa) and Anadarko Petroleum (NYSE:APC) uspended some Gulf activity.
However, the commodity continued to benefit from the prospect of extended oil production cuts by the Organization of the Petroleum of Exporting Countries.
Russian President Vladimir Putin on Wednesday said that a pledge by OPEC and other producers, including Russia, to cut oil output to boost prices could be extended to the end of 2018, instead of expiring in March 2018.
King Salman of Saudi Arabia met with Putin in Moscow on Thursday. Though he made no firm pledge to extend a deal between OPEC, Russia and other producers on cutting supplies, Salman said his country was "flexible" regarding suggestions to prolong the pact until the end of 2018.
Oil prices have been well supported in recent weeks amid growing optimism that the crude market was well on its way towards rebalancing as data showed strong compliance from major producers with their supply cut agreement.
In May, OPEC and non-OPEC members led by Russia agreed to extend production cuts of 1.8 million barrels per day for a period of nine months until March 2018 in a bid to reduce global oil inventories and support oil prices.
Elsewhere, gasoline futures were flat at $1.622 a gallon, while natural gas futures declined 0.44% to $2.910 per million British thermal units.