Fortescue Metals intends to appeal Australian Competition Tribunal's decision not to oblige Rio Tinto and BHP Billiton to open up their primary Western Australia rail lines to third party mining groups.

In an official statement, Fortescue said that it would probably make an appeal to the Federal level after re-examining the tribunal's decision on the Hamersley and Newman lines.

However, Fortescue did persuade the tribunal court to compel BHP Billiton to open its Goldsworthy rail line to third party mining groups.

Russell Scrimshaw, executive director of Fortescue Metals, said this was a major victory for them, as it substantiated their arguments for third parties' right to access.

"The Tribunal has upheld Treasurer Wayne Swan's declaration that there is spare capacity on the railway lines, which can be utilised to maximise the economic benefits to Australia from increased iron ore exports," Mr. Scrimshaw said.

"[It was] an excellent outcome for Australia."

In recent trading outcomes, the shares of Fortescue declined by 1.94 per cent, or eight cents, to $4.04.