big miners may have to share pilbara rail line

The Western Australian Government may move to force the miners BHP-Billiton and Rio Tinto to allow other companies to use their crucial rail lines in the Pilbara, after a draft confidential report recommending controversial new laws.

The confidential report, yet to be handed to Cabinet, aims to encourage more competition in the Pilbara by allowing junior miners to exploit their small reserves.

The draft recommendations propose that BHP and Rio operate the Pilbara rail system but charge junior miners a haulage fee.

The third parties would also have to build their own spur lines and rail sidings.

State Development Minister Eric Ripper says some miners are concerned about the regime.

"We're still working through those issues," he said.

"It's a difficult exercise to get an appropriate balance of owners of infrastructure and the interests of those people who seek access to that infrastructure."

Mr Ripper says the Government wanted the report six months ago.

"Progress has been a bit slower than I would have hoped but these are difficult and complex issues with huge commercial and economic interests for the state at stake," he said.