Oil markets are delicately poised as Opec prepares for its upcoming 30 November meeting in Vienna where a probable extension of production curbs will be center stage.

The current output deal between Opec and 10 non-members is set to expire in March, and it is looking increasingly probable that an extension will be agreed upon this month in Vienna. But participants should perhaps consider trimming each country’s production allocation to dampen recent price gains.

Oil prices have...