Research and consulting group Wood Mackenzie said the disruption to supply affected 91% of the nation’s hard coking coal exports and that the mines affected by the floods made up 55% of Australia's total coal exports.

Wood Mackenzie said if all 46 mines affected by the floods ceased production for a month, that would represent 14 million tonnes in lost exports. The Queensland Resources Council has previously estimated that the coal industry is losing $100 million a day in exports because of the floods.

"The impact of the decrease in exports in this ongoing situation will be felt strongly in global coal markets," Wood Mackenzie said in a statement.

"As the rainfalls have intensified on January 11, it is reasonable to assume that hard coking coal prices could reach between $US400 and $US500 per tonne."

Since the floods crisis, spot prices have risen to $US275/t, well above the quarterly contract for hard coking coal of $US225/t, Wood Mackenzie said.

Rio Tinto, BHP Billiton, Anglo American, Xstrata, Wesfarmers, Macarthur Coal and other producers in the Bowen Basin have issued force majeure declarations.

Demand for thermal and metallurgical coal is increasing in Asia, leading to a tight supply situation that is even worse than the shortage caused by the 2008 floods in Queensland.

"Therefore, most supply regions have been producing at capacity and replacement tonnage will be difficult to secure," Wood Mackenzie said.

In addition, steel production increased in October last year, while the situation has been exacerbated thanks to supply disruptions in Colombia, Venezuela and South Africa.

Turning to power generation, the consultancy said that in the Atlantic Basin, spot prices for thermal coal had reached $US130/t delivered into Europe as the northern hemisphere endured a harsh winter.

But in the Pacific Basin, thermal spot prices had already risen sharply to $US140/t from Port of Newcastle and could approach or exceed $US197/t, according to Wood Mackenzie.

Platts International Coal Report editor Mike Cooper reportedly said coal exports coming out of Australia had dried up, with buyers looking to other markets to shore up supply.

At present, only a handful of vessels are leaving Queensland ports with Xstrata the only major coking coal producer in the Bowen Basin not to have declared force majeure.

“The only mine producing and exporting to customers at the moment is Xstrata’s Oaky Creek mine from the Bowen Basin and buyers from Asia are having to make do with supplies from North America to bridge the gap in the market at the moment,”Australian Financial Review quoted Cooper as saying in a webcast.

According to analysis from Commonwealth Bank, growth in coking coal exports is tipped to slow from a previous forecast of 10% to around 3% for 2011, with Australian coking coal exports expected to come in at 146Mt for the year.