The world's biggest oil producers are pumping like there is no tomorrow.

The result: Oil prices fell to $43.08 a barrel, a six-year low.

OPEC said Tuesday that its output surged to a three-year high in July. The cartel produced 31.5 million barrels a day, more than 1.5 million barrels above the ceiling it agreed to just a month earlier.

The added oil came from Iran, Iraq and Saudi Arabia. Iran's higher output - its highest since 2012 -- is a sign it is ready to take advantage of the proposed nuclear deal.

Sanctions have long restricted Iran's oil production and exports, and the country is eager to regain its status as a global energy power. Iran boosted its production by 32,300 barrels a day in July to 2.86 million a day, the OPEC report said, citing secondary sources.

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Non-OPEC oil production is also surging. The report said oil output grew faster than expected in the North Sea, China, Colombia, Russia and the U.S.

"US production remains near the highest level in four decades, although the commodity price is telling the U.S. shale sector to shrink," the report said.

The data show the fierce battle for the oil market is not easing. Oil producing countries refuse to cut supply even as the prices tumble.

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