The Port Talbot steel plant explosion could cost insurers up to £500m, it is feared.
Earlier this month, Anglo-Dutch steelmaker Corus suffered a major explosion at its South Wales plant. Three people were killed and ten injured.
Insurers are now saying the accident is the largest fire loss in the London Market this year, costing up to £500m.
Business interruption, material damage and general liability claims are expected to be huge.
One liability insurer said: "This brings further pressure on the market to make sure risks are properly funded."
It is understood AXA was the lead insurer. Irontrades, Groupama and Allianz Cornhill are also said to have covered the steelworks.
