Rio Tinto has announced a $637.8 million investment in its Pilbara expansion plans, aimed at fast tracking the development of the company's iron ore production capacity.


The mining giant has announced that the investment will allow for a boost of 333 million tonnes per year in output as of the first half of 2015, putting it six months ahead of the planned completion date.


The expansion is part of a five-year plan started in 2010 designed to beat Rio's competitors in building its market share, according to Rio Tinto chief executive Iron Ore and Australia, Sam Walsh


“Thanks to this faster pace of expansion we will be bringing extra tonnes to market earlier,” said Mr Walsh.


“We are taking the opportunity to bring forward the next phase of our major capacity expansion to reap the benefits early and at no additional cost.”


Much of the spending will be focussed to the port and rail infrastructure used by the company in removing major bottlenecks of supply as well as the construction  of accommodation and procurement of mining and construction material


"The demand outlook continues to be strong with supply lagging elsewhere in the industry and we are seeing new supplies proving slower to materialise than predicted." Mr Walsh added.


Rio's expansion of its Pilbara operations comes as the company struck an agreement with the local Ngarluma, Kuruma Marthundunera, Puutu Kunti Kurrama and Pinikura, Nyiyaparli and Ngarlawangga Indigenous populations on a royalty and employment scheme due to last 40 years.


“For Aboriginal people they help to create a future where culture and law is sustained and celebrated, where their children and grandchildren’s children will enjoy a far greater opportunity for health and education and, as a result, jobs and wealth creation.”