A deal to freeze oil output by OPEC and non-OPEC producers fell apart on Sunday after Saudi Arabia demanded that Iran join in despite calls on Riyadh to save the agreement and help prop up crude prices.
Some 18 oil nations, including non-OPEC Russia, gathered in the Qatari capital of Doha for what was expected to be the rubber-stamping of a deal - in the making since February - to stabilize output at January levels until October 2016.
But OPEC's de facto leader Saudi Arabia told participants it wanted all members of the Organization of the Petroleum Exporting Countries to take part in the freeze, including Iran, which was absent from the talks.
Tehran had refused to stabilize production, seeking to regain market share post-sanctions. After five hours of fierce debate about the wording of a communique - including between Saudi Arabia and Russia - delegates and ministers announced no deal had been reached.