LONDON - OPEC gathers in Vienna this week for a ministerial meeting to decide on the cartel’s oil production ceiling, as a predicted drop in demand risks weighing on high crude prices despite Middle East unrest.

The Organization of Petroleum Exporting Countries, which pumps out 35 per cent of the world’s oil, may also finally decide on a new head after a vote to appoint a successor to OPEC Secretary-General Abdullah El-Badri was postponed in June.

The 12-nation cartel, which includes the world’s biggest oil exporter Saudi Arabia and Iran—currently under an oil embargo—was to hold a regular output meeting at OPEC’s headquarters in the Austrian capital on Wednesday.

“OPEC’s official production target is unlikely to change at the December meeting,” noted Jason Schenker of Prestige Economics research group.

“Nevertheless, there is likely to be a heated debate over who will be OPEC’s next secretary-general.” At its last meeting in June, OPEC opted to keep its oil output ceiling at 30 million barrels per day (mbpd) — after agreeing on the level a year ago—and vowed to eliminate over-production.