The Queensland floods could have a ‘significant long-term effect’ on the global steel industry, the premier of the Australian state has warned.

The BBC reports that Anna Bligh's comments came as three quarters of the state's coal fields are unable to operate due to being flooded.

The situation in Queensland is being closely watched by the global steel industry, because it exports half the coking coal needed to make the metal.

However, steel analysts say it is too soon to be able to quantify the impact.

They say this is because it depends on how long the floods continue, and the size of the coking coal stockpiles the world's steelmakers currently have in place.

Ms Bligh told Australian broadcaster ABC: "We have three-quarters of all of our coal fields unable to operate and unable to supply markets."

Railway lines that transport the coal to ports for export have also been flooded.

The price of Queensland coal has jumped to $253 per tonne from $225 in the past three weeks.

However, prices peaked at $305 during the last serious flooding in the state in 2008.