Torrential rain in the Australian state of Queensland has halted exports from mines accounting for 40 per cent of global coking coal capacity, raising the prospect of higher prices for the key steelmaking ingredient.

Anglo American joined a string of companies and declared force majeure in five mines in Queensland – effectively saying that it would be unable to meet supply contracts because of events beyond its control. The heaviest summer rains yet recorded have crippled the export infrastructure in Queensland, which accounts for half of the world’s production capacity in coking coal.

Higher prices for coking coal are likely to push up the cost of steel, which is critical to the global economy as it filters into the cost of everyday goods. The price of iron ore, the other main steelmaking ingredient, has risen by 44 per cent this year.