Crude prices dropped to near seven-year lows after the Opec meeting in Vienna passed without a change in policy on oil production and exports.
The Opec basket crude price dropped to a close of $37.89 a barrel on 3 December, its lowest since the final day of 2008.
Opec will continue with the Saudi-led policy to maintain oil production and exports despite the global oversupply which has led to a collapse in prices since the second half of 2014.
Riyadh has increased oil production to record levels in 2015 and it continues its strategy to protect market share in Asian oil-buying countries, despite calls from some Opec members to cut output in order to support prices.
The 13-member oil-exporting group has been producing well above its 30 million barrel-a-day (b/d) quota target since its decision in November 2014 to let prices be determined by market forces. Current Opec production levels are estimated to be at about 31.4 million b/d.
In our view, the lack of guidance on a production quota underlines the discord among members, said Barclays analyst Miswin Mahesh in a research note following the Opec meeting.
Past communiques have at least included statements to adhere, strictly adhere, or maintain output in line with the production target. This one glaringly did not, he added.
Barclays said it would be difficult for Opec to achieve higher market share, higher prices and higher demand through a nominal target that the members continue to breach.
Opecs position will be further complicated by a resurgent Iran, which aims to increase exports by as much as 1.5 million b/d in 2016 after the lifting of sanctions against its oil sector.
Saudi Arabia, the worlds largest oil exporter and most influential Opec member, has been pursuing the strategy to maintain production in the hope that non-Opec producers will be impacted by lower prices.
High-cost producers, most notably in the US shale oil industry, have been impacted by the lower price environment but so far there are no signs of crude prices recovering to sustainably higher levels.
Saudi Arabia has said in the past that it is willing to take action to boost oil prices but only in cooperation with other Opec members as well as other large oil exporters such as Russia.
We have said on more than one occasion, we are willing to cooperate with anyone who can balance the market, Saudi Arabian oil minister, Ali al-Naimi, said at the Opec meeting in Vienna.
Barclays, which was one of the most bullish on oil price forecasts for 2016, slashed its prediction for Brent prices in 2016 by $3 ahead of the Opec meeting to $60 a barrel.
The Brent price closed at $43 a barrel on 4 December.