This story was updated with more information at 7:05 AM CST. It was originally posted at 6:49 AM CST.
OPEC and its allies are working towards cutting oil output by up to 1.5 million barrels per day (MMbbl/d) but could fail to reach a deal if no compromise is found with non-OPEC Russia, the Saudi energy minister said on Dec. 6.
As the Organization of the Petroleum Exporting Countries gathered in Vienna, it awaited news from Russian Energy Minister Alexander Novak, who flew home from the Austrian capital earlier for possible talks with President Vladimir Putin.
Novak returns to Vienna on Dec. 7 for discussions among Saudi-led OPEC and the group's allies.
OPEC hopes to prop up the price of crude, which has fallen by almost a third since October, but U.S. President Donald Trump has demanded it make oil cheaper by refraining from output cuts.
"We hope to conclude something by the end of the day tomorrow ... We have to get the non-OPEC countries on board," the Saudi minister, Khalid al-Falih, told reporters.
"If everybody is not willing to join and contribute equally, we will wait until they are."
Asked whether OPEC could fail to reach a deal, Falih said all options were on the table. Possible output cuts by OPEC and its allies ranged from 0.5 MMbbl/d to 1.5 MMbbl/d, and 1 MMbbl/d was acceptable, he said.
OPEC began its closed-door meeting around 1100 GMT.
Brent oil futures fell as much as 5% to below $59 per barrel on fears that there could be no deal but later recovered somewhat, trading down 2% by 1230 GMT.
"One million barrels per day may disappoint many. But should the cut be from a September or October baseline, rather than November, the net impact would be sufficient to limit storage builds," Greg Sharenow, executive vice-president for Pimco, said on the sidelines of the OPEC meeting.
"It is unlikely to spark a meaningful price rally, but also will not be so dire either. In many respects it is the middle road, which may be the optimal solution," said Sharenow, who helps manage a $15 billion commodities fund at the $1.77 trillion U.S. investment management firm.
OPEC delegates have said the group and its allies could cut by 1 MMbbl/d if Russia contributed 150,000 bbl/d of that reduction. If Russia contributed around 250,000 bbl/d, the overall cut could exceed 1.3 MMbbl/d.
Novak said on Dec. 6 that Russia would find it harder to cut oil output in winter than other producers because of the cold weather.
Oil prices have crashed as Saudi Arabia, Russia and the United Arab Emirates raised output since June after Trump called for higher production to offset lower exports from Iran, OPEC's third-largest producer.
Russia, Saudi Arabia and the United States have been vying for the position of top crude producer in recent years. The United States is not part of any output-limiting initiative due to its anti-trust legislation and fragmented oil industry.