Only five non-OPEC countries have sent representatives to a meeting of OPEC and non-OPEC oil market experts that began on Wednesday at the petroleum exporter group's Vienna headquarters.
The Organization of the Petroleum Exporting Countries (OPEC) had invited eight non-member nations including Russia for talks on the market, ahead of OPEC's policy-setting meeting on Dec. 4.
Wednesday's talks are not expected to increase the prospect of cooperation on oil supply curbs or show much support for a price band proposed by OPEC member Venezuela.
But participants could agree to share information or continue to assess the market, OPEC delegates and analysts say.
"There will be an exchange of views, discussion of the market and the OPEC secretariat's presentation, but I don't think there will be an agreement to coordinate," an OPEC delegate said.
Of the non-OPEC countries invited, Mexico, Russia, Colombia, Kazakhstan and Brazil are understood to have sent representatives. A similar meeting held in May failed to achieve cooperation between the two sides.
Non-OPEC producers have refused to work with OPEC in cutting supply to reduce a surplus that has prompted oil prices to sink below $50 a barrel from $115 in June 2014.
In turn, OPEC has refused to limit supply alone and many of its members have raised output.
Most OPEC countries have sent their national representatives - oil experts who rank below ministers - to the event, although Venezuelan Oil Minister Eulogio del Pino and his Ecuadorean counterpart Pedro Merizalde-Pavūn are attending.
Cash-strapped member Venezuela is pushing for OPEC and non-OPEC cuts and has proposed reviving OPEC's price band mechanism, attempting to set a price floor of $70 a barrel.
But the Gulf OPEC members, including top exporter Saudi Arabia, have shown no interest in returning to a strategy of supporting prices, seeking instead to fight for market share.