OPEC members failed to agree to an oil production ceiling on Friday at a meeting that ended in acrimony, after Iran said it would not consider any production curbs until it restores output scaled back for years under Western sanctions.



A final statement was issued with no mention of a new production ceiling, apparently allowing member countries to continue pumping oil at current rates into a market that has been oversupplied.

Crude oil futures for January delivery tumbled $1.11 to settle at $39.97 US a barrel in New York.

OPEC's secretary general Abdullah al-Badri said the body could not agree on any figures because it could not predict how much oil Iran would add to the market next year, as sanctions are withdrawn under a deal reached six months ago with world powers over its nuclear program.



Most ministers left the meeting without making a comment. Iranian oil minister Bijan Zangeneh had said before the meeting that Tehran would be prepared to discuss action only when his country reached full output levels, if and when Western sanctions are lifted.



Saudi oil minister Ali al-Naimi earlier had said he hoped growing global demand could absorb an expected jump in Iranian production next year: "Everyone is welcome to go into the market."



Iran has repeatedly said it would boost production by at least one million barrels per day when sanctions are lifted.

Without curbs elsewhere, this would add to a global glut, as the world is currently consuming up to two million bpd less than it is producing.