June 19 (Bloomberg) -- Coal shipments from Australia's Newcastle port, the world's biggest export harbor for the fuel are behind target for this year because of weather disruptions and railroad constraints.

Cargoes are about 2 million metric tons short of the objective so far, Port Waratah Coal Services Pty, operator of the terminals at the harbor, said in an e-mailed statement today. Rio Tinto Group, Xstrata Plc and BHP Billiton Ltd. are among mining companies that supply coal through Newcastle, which aims to export 98 million tons of the commodity this year.

Newcastle port operates an export quota system that seeks to better match capacity with demand and reduce the queue of ships waiting outside the harbor. Bottlenecks at Newcastle, together with flooding in Queensland state to the north and rising demand helped drive prices for power-station coal from the Australian port to a record last week.

``Poor weather, demand mix and coal-chain reliability issues have contributed to the performance drop,'' Port Waratah said in the statement. It will ``use appropriate mechanisms available within the system to manage allocations and the vessel queue throughout 2008, in consultation with the coal industry.''

Coal export allocations at Australia's Newcastle port may be cut by 1 million metric tons in the third quarter, The Tex Report said yesterday, citing unidentified traders.

The reduction is aimed at trimming the number of ships incurring demurrage, a penalty paid to ship-owners waiting to load cargo beyond a scheduled time, Tex reported. It would also cut total coal shipments from the port this year to 91.9 million tons, the newsletter added.

The index for power-station coal prices at the New South Wales state port rose $1.70, or 1.1 percent, to $160.23 a metric ton in the week ended June 13, according to the globalCOAL NEWC Index. The volume shipped in the week ended 7 a.m. local time June 16 fell 14 percent to 1.24 million tons from 1.44 million tons a week earlier, Newcastle Port Corp. said on its Web site.

To contact the reporter on this story: Jesse Riseborough in Melbourne at jriseborough@bloomberg.net

Last Updated: June 19, 2008 01:31 EDT