Fortescue Metals Group has had a High Court win that opens the way for a further review of its access to Pilbara rail lines owned by mining giants BHP Billiton and Rio Tinto.
Fortescue has fought a long-running battle to gain access for smaller miners to four rail lines operated by BHP and Rio in the Pilbara.
Last year, the Federal Court ruled in Rio Tinto's favour after FMG attempted to overturn an Australian Competition Tribunal ruling that left Rio Tinto's Hamersley rail line closed to smaller miners.
The Hamersley line connects 10 of Rio Tinto's 12 mines to the coast.
Fortescue was also unsuccessful in challenging the tribunal's decision to declare Rio Tinto's Robe River railway open to third parties until 2018, rather than 2028, as sought by FMG.
Fortescue had also sought access to BHP's Goldsworthy and Mt Newman lines.
On Friday, the High Court ruled the Australian Competition Tribunal's review had not been undertaken according to the law.
"The High Court quashed the tribunal's determinations and remitted the matters for the tribunal for determination according to law," it said in a judgment.
The High Court found the tribunal had been presented with materials and evidence far in excess of what was placed before the federal infrastructure minister when it made its ruling.
"The High Court held that the tribunal should have considered only those materials considered by the minister supplemented, if necessary, by any information, assistance or report given to the tribunal by the National Competition Council in response to a request made under ... the act."
Fortescue said it was confident the submission of its rail access application to the tribunal for fresh consideration would result in a declaration for third party access.
Chief executive Nev Power said it was a welcome development in the long battle for access to Rio Tinto's line.
"We remain committed to the principle of third party access and are proud to operate our own railway on an open access basis carrying third party ore," he said in a statement.
The company transports iron ore on behalf of BC Iron, its 50/50 JV partner in its Nullagine joint venture.
Mr Power said third party rail access would help smaller miners develop deposits without duplicating expensive and unnecessary rail infrastructure to generate export revenue for Australia.
