The Organization of the Petroleum Exporting Countries (OPEC) agreed last month to restrain output to boost prices, which have been slumping at less than half their mid-2014 levels due to a persistent supply glut.
Iraq on Sunday called for an exemption, adding to the list of members seeking special treatment. The expectation was that Libya, Nigeria and Iran should be exempt as their output had been hit by wars and sanctions, OPEC sources said.
While doubts linger about OPEC's ability to implement the cut, the market has been leery of reading too much into it ahead of a meeting scheduled for the end of November, said David Thompson, executive vice-president at Powerhouse, an energy-specialized commodities broker in Washington.
"All that should be bearish, but the market is reluctant to get significantly short in front of that because of obviously, a political decision could catch them on the wrong side," he said.
OPEC has been seeking cooperation from external producers, though non-member Russia said it would not cut output, but rather freeze it, the sources said.
OPEC members are expected to have a technical meeting on Friday and one with officials from non-member countries on Saturday.
OPEC oil ministers meet on Nov. 30, and are expected to hash how then much individual countries should cut.