"The medium-term system, designed by Port Waratah Coal Services (PWCS) in consultation with coal producers and customers of Hunter Valley coal, is designed to prevent a large queue of vessels from re-forming at the port," ACCC chairman Graeme Samuel said.

The system will cut the amount of coal each producer can export through the Newcastle port on a pro rata basis so the overall amount handled better matches what can be processed by the coal chain. The solution is designed to substantially reduce the significant demurrage costs that arise in an excessive queue and will provide a solution until coal chain expansion can kick in.

Logistics providers in the Hunter Valley have developed a long-term program of coordinated investment to expand the capacity of the coal chain, Samuel said. Part of this program includes increasing coal chain capacity from current annualised throughput of 86 million tonnes to 120Mtpa in the next few years.

PWCS estimates demurrage savings under the new scheme will amount to between US$106 million to US$179 million.

"The ACCC is satisfied that under the system the total volume of coal exports from the Hunter Valley is unlikely to be reduced, particularly given additional flexibility measures introduced under the new scheme,” he said.

Samuel added that the medium-term system was unlikely to remove the pressure on expanding the capacity of the Hunter Valley coal chain.

In related news, the Queensland Competition Authority (QCA) last week failed to deliver a decision on the Dalrymple Bay coal terminal.

The QCA met to decide what price coal producers should pay to use the Dalrymple Bay terminal near Mackay. Operator of the terminal, Prime Infrastructure, will not expand capacity from 54Mt to 90Mt unless it is allowed to charge more than $A1.53 per tonne, the figure recommended in a draft ruling in October. This was well below the company's ambit claim of $A2.77.

The QCA plans to post the ruling on its website on Wednesday.