Fortescue Metals (FMG) is challenging the recent decision forcing it to negotiate access to its rail line with fellow miner Brockman.
The iron ore miner has gone to WA's Supreme Court to ask for a judicial review of the state's Economic Regulation Authority's decision last month.
Fortescue's chairman Andrew Forrest argues that Brockman's Pilbara iron ore project is unviable and its presence would block access for more economic projects.
Fortescue also wants to charge up to $576 million a year for access instead of the limit of $316.9 million a year the ERA allowed.
Fortescue's rail infrastructure is open to third-party access by negotiation because it was built after rules were introduced in WA in 2000, unlike other monopoly Pilbara railways owned by BHP Billiton (BHP) and Rio Tinto (RIO).