Herald Sun reported that Rio Tinto has fired a new salvo in its battle to fend off predator BHP Billiton, reiterating its claim to have the biggest and best iron ore operation in the Pilbara amid mounting speculation that BHP will move earlier than expected with an improved offer.

Mr Sam Walsh CEO of iron ore business of Rio at a Perth media briefing said that that Rio has the largest iron ore resource and reserve base in the Pilbara, expected to sustain multiple decades of future mining.

Rio has flown in journalists from London and New York as well as locally for a four day tour of its iron ore operations as part of its PR campaign ahead of the real battle.

Rio's operations in the Pilbara comprise 11 mines, three ports and some 1300 kilometer of rail network.