Rio Tinto could overtake Brazilian giant Vale to become the world's biggest global producer in iron ore in the next one to two years.

The two are vying for the crown of biggest producer in 2015, with both expecting calendar 2015 production of 340 million tonnes.

Vale has held the crown since 1974.

On Thursday, Rio cut its full-year guidance to 340 million tonnes, from "approaching" 350 million tonnes.

Deutsche Bank analyst Paul Young said "the scene could be set for a change in the iron ore production leadership board".

"Rio hit a new record run rate in the second quarter of 320mtpa and will obviously have to exceed this in the second half to hit its 340mt guidance," Mr Young said.

"It is now running very close to Vale's production level and may overtake it for a year or two."

However, on an equity basis Vale is still dominant.

Vale is cutting costs by replacing 25 million to 30 million tonnes of unprofitable iron ore with cheaper production.

However, it is sticking to its supply target of 340 million tonnes in 2015, meaning the high-cost tonnes it is taking out of the market will be replaced by lower-cost iron ore.

Rio will need to eat into stockpiled ore to hit its guidance for 2015.

The drawdown in iron ore stocks in the quarter would help Rio's earnings and balance sheet, Deutsche said.