KEY POINTS
  • OPEC and non-OPEC members will meet in Vienna, Austria, on Thursday, with the aim of reaching an accord over possible output cuts in order to prop up tumbling oil prices.
  • Crude futures have fallen more than 25 percent since climbing to a four-year peak in early October, amid intensifying oversupply concerns and worries over slowing economic growth.
Secretary General of OPEC, Mohammed Barkindo (R), Russia Energy Minister Alexander Novak (L), Saudi Arabia's Minister of Energy, Industry and Mineral Resources, Khalid Al-Falih (C) hold a joint press conference during the 173rd Ordinary Meeting of the Organisation of Petroleum Exporting Countries (OPEC) in Vienna, Austria on November 30, 2017.

The energy alliance between OPEC kingpin Saudi Arabia and non-OPEC heavyweight Russia faces its "toughest test yet" next week, analysts have told CNBC, ahead of a much-anticipated meeting between the influential oil cartel and its allies.

OPEC and non-OPEC members will meet in Vienna, Austria, on Thursday, with the aim of reaching an accord over possible output cuts in order to prop up tumbling oil prices.