Emerging iron ore mining giant Fortescue Metals Group Ltd revealed its approved investment plan up to $US8.4 billion or $A8.51 billion that would be used to ramp up the mining firm's current iron ore production capacity to an estimated 155 million tonnes per annum (MTPA).

Prior to the new investment allocation, Fortescue had achieved an average of 42 MTPA in financial year 2009/10 and the company said in statement released on Friday that the budget approval "sets the platform for a major $US8.4 billion works and procurement expansion program to commence at Fortescue's Chichester and Solomon hubs."

The move, according to FMG chief executive Andrew Forrest would also enable the iron ore miner "to leverage its existing infrastructure and its massive land holding across the Pilbara to exponentially increase product sales within key markets of Asia, Europe and Australia."

At the same time, Mr Forrest expressed confidence that the company possesses the needed expertise to accelerate its planned expansions in the iron ore mining industry that he said has seen additional boosts from demand surges, locally and abroad.

The expansion targets would be largely funded by the recent debt facilities refinancing of Fortescue, where the company is set to pour a total of $US4.6 billion in the Solomon mining area for the redevelopment of its exiting port, train unloader and main line rail network.

Fortescue said that a new rail line would also be constructed in the same area to enhance the hauling movement capacity of the mining site.

In Chichester Hub, the company is planning to spend some $US1.5 billion that it hopes would improve the production capacity of the Cloudbreak and Christmas Creek in the area to a total of 90 MTPA.

The remaining $2.3 billion would be utilised by Fortescue in developing new operations in Solomon with some focus investments on attached infrastructure in the area, where initial export output is expected to come online by the September quarter of 2012.

Fortescue is expecting a combined yield of 90 MTPA from both the Cloudbreak and Christmas Creek iron ore mining sites, with projected additional five MTPA from FMG's joint venture with BC Iron.

The iron ore miner expressed optimism that it would be able to achieve the 155 MTPA that it is aiming and is ready to ship the yields on any additional capacity on hand, revealing too that it has secured assurance from the Port Hedland Port Authority that at least 120 MTPA of the company's production would be given priority status.