Mining giant Rio Tinto has welcomed a ruling by the Australian Competition Tribunal that it doesn't have to open its Pilbara railways to other operators.
Fortescue Metals Group has tried for years to get access to the company's Robe and Hamersley rail lines to transport its iron ore to port, but Rio has always firmly opposed the infrastructure sharing concept.
Rio Tinto Iron Ore acting chief executive Paul Shannon described the tribunal's ruling as great news for the company.
"Rio Tinto runs a highly efficient railway that is fully integrated with our port and mine operations," he said.
"This would be severely hindered if third parties were allowed to run trains on our rail network, not to mention the knock-on negative effect on the WA and national economies from creating such inefficiencies."
In an earlier tribunal decision, FMG initially won limited access to some of Rio Tinto's railway lines but the High Court quashed the ruling and sent it back, saying it was "not undertaken according to law".
Australia's Competition and Consumer Act allows third parties to seek access to infrastructure owned by others when the government determines it would be uneconomical for anyone to develop another facility to provide the service.
Rio shares were off 18 cents to $69.42 while FMG shares were up nine cents, or 1.82 per cent, to $5.03.