Drilling results and ongoing assessment of assets in the Pilbara, Western Australia have revealed a 2bnt addition to Rio Tinto's mineral resource base.

This latest work, (drilling, re-interpretation and re-estimation of 14 deposits) has expanded Rio Tinto's mineral resource base in the Pilbara by 2bnt, which will be in addition to the currently reported 14.4bnt of mineral resources and 2.8bnt of ore reserves.

Sam Walsh, chief executive, iron ore and Australia said the expanded resource base would help underpin Rio Tinto's development of its Pilbara operations to a capacity of 333Mt/y in 2015, and for decades to follow.

He said: "Over the past ten years, we have moved to strengthen our ore reserves and mineral resources, having drilled 3.3M metres. We plan to drill 3.9M metres in the next five years - a programme unprecedented in the history of the iron ore business, demonstrating our commitment to sustained development in the Pilbara."