Oil producers that supply almost half the world’s crude failed Sunday to negotiate a production freeze intended to strengthen prices.  Amid strains between regional rivals Saudi Arabia and Iran, the world's largest oil exporters could not find enough common ground to hold the line on output that has sent the world's oil supply surging and prices plummeting. The conference's outcome was thrown into doubt after Iran made a last minute decision not to attend.

Qatar's oil minister told reporters that the group "needs more time" to construct the outlines of a deal to freeze output, citing "improved fundamentals." Recently, oil prices have crept up from below $30 to levels just above $40 on Friday.

Tehran is strongly resistant to the idea of an output freeze, as it attempts to recoup lost market share after being freed from the yoke of Western sanctions. With the country declining to participate, the meeting's delegates appeared to doubt how effective a freeze could be if it didn't include Iran.

"With Iran, we respect their position and through further consultation, we don't know how their future will unroll," Qatar's oil minister said. "It was a sovereign decision by Iran. A freeze would definitely be more effective if OPEC and non-OPEC" participated he added.

Market observers had hoped that the meeting's participants could strike a 'gentleman's agreement' that would at least save face and serve as a bridge to June's OPEC meeting. However, the collapse of the talks suggest that global crude prices may come under renewed pressure.

In a research note to clients on Friday, Capital Economics pointed out that because Russia and OPEC members were already pumping crude at record levels, the effectiveness of a freeze would be marginal at best.

"Freezing OPEC and Russian output at current high levels will not reduce excess supply without a pick-up in demand or supply cuts by non-OPEC producers," the firm said. "As such, the recent rally in oil prices could appear premature and we would not be surprised if the market registered some disappointment come Monday morning."