VIENNA — OPEC will seek on Wednesday to defy expectations and finalise a deal in Vienna reducing its oil output for the first time in eight years in an effort to boost painfully low crude prices.

It remained to be seen however whether the cartel’s big guns Saudi Arabia, Iraq and Iran can overcome their fierce rivalries and agree who will do most of the heavy lifting.

If they fail to agree a deal, experts expect oil prices, at under US$50 per barrel already less than half 2014 levels, to head further south perhaps to $40 or even $30.

In addition, a failure in Vienna would deal a further blow to the already damaged credibility of the Organization of the Petroleum Exporting Countries, 56 years after its creation.

Arriving in the Austrian capital on Tuesday, Algerian Energy Minister Noureddine Bouterfa appeared hopeful.

"The discussions are going in the right direction," he told reporters.

Analysts, however, took a different view.

"We now see a very low chance for an OPEC cut," said Bjarne Schieldrop at SEB.

"Now it becomes imperative to save face. To save the appearance that OPEC matters. Kicking the can to the next OPEC meeting in half a year’s time," he said. — AFP