Ministers of the Organisation of the Petroleum Exporting Countries arriving in Vienna on Sunday have indicated concern that oil prices may fall. Though the eleven-nation group is unlikely to officially reduce its production quota when it meets on Monday, the change in ministers’ tone could be a harbinger of things to come.

“Inventories are very comfortable, prices are coming down and nobody is concerned about a shortage of supply,” Ali Naimi, Saudi Arabia’s oil minister and Opec’s most powerful member, said as he arrived in Vienna.