11 non-OPEC countries including Russian Federation are said to back the decision, which means that the group of 22 oil-producing countries will maintain 1.8m bpd of supply cuts until March 2018.
OPEC will convene its next ordinary meeting in Vienna on November 30, the organization announced late Thursday.
Global oil cuts have helped push crude prices above $50 a barrel in 2017, which has helped member-nations sustain their revenues, as majority of them rely heavily on energy revenues. Medium term, we remain positive on the oil price and forecast the price on Brent crude to average USD60/bl in 2018 on the back of a lower United States dollars and somewhat tighter oil market.
U.S. West Texas Intermediate (WTI) crude futures CLc1 were back below $50, at $48.61, down 29 cents, or 0.6 percent.
Both benchmarks were still up over 15 percent from May lows.
The Organization of the Petroleum Exporting Countries (OPEC)'s decision to extend the cuts from January comes as the world market saw oil increase to $50 a barrel in 2017, which gave fossil fuel producers a reprieve from a almost four year oil glut.
They expressed its deep appreciation to the commitment and valued contribution of the Joint Ministerial Monitoring Committee (JMMC) and the Joint Technical Committee (JTC) that have provided the transparency required in implementing the decisions taken previous year in a timely and equitable manner.
"There have been suggestions (of deeper cuts), many member countries have indicated flexibility but ... that won't be necessary", Falih said.
But the news that the cuts will be extending for nine months past the end of June has sent the price of oil tumbling.
With U.S. output rising steadily and OPEC and its allies potentially ramping up production in 2018 to regain lost market share, many traders are already expect another price slump.More news: Trump travel ban blocked; fight headed for Supreme Court
"There's still an oversupply to wrestle with", said Simon Flowers, chief analyst at the consultant.
"Nine months was priced in", Sen said. But after Oil prices bottomed around the $26-handle, rumors of OPEC action began to drive the bid and, eventually we had the announcement of the agreement between OPEC and non-OPEC Oil producers that was devised to help stem supply in order to drive prices higher. That's because USA shale oil producers have taken advantage of the uptick in prices since a year ago to ramp up production.
OPEC oil ministers were continuing their discussions with non-OPEC producers. Non-OPEC producers were scheduled to meet OPEC later in the day.
The OPEC and the select group of 11 non-OPEC producers announced an agreement today to extend existing production cuts through the first quarter of 2018.
But since fracking required substantial investment, when oil prices plummeted in 2015 and 2016, output from shale in the United States fell around 900,000 barrels a day, equivalent to nearly 1 per cent of the global supply.
Al-Falih also said Opec needs to be evolve, work and coexist with other producers.
The energy minister said the OPEC Monitoring Committee proposed to extend the agreement for another nine months and the proposal was unanimously accepted and another such meeting will be held in Vienna on November 30, 2017.
He added that OPEC members Nigeria and Libya would still be excluded from cuts as their output remained curbed by unrest.