Insurers' published losses from the September 11 attacks in the US have exceeded $21bn (£14.8bn), making the assaults officially the most expensive disaster in history.

Figures from more than 100 insurers, which include net losses and claims, show the cost of the attacks has already soared past that of Hurricane Andrew, previously the greatest ever insured loss with costs of $20bn (£14bn).

The information has been collated by Thomson Financial Insurance Solutions, which has drawn up a table showing data from insurers worldwide.

The greatest losses on the table are those suffered by Berkshire Hathaway, $2.2bn (£1.5bn); Munich Re, $2.1bn (£1.5bn) and Lloyd's of London, $1.9bn (£1.3bn).

With more than 100 companies represented, it is the most definitive set of industry figures widely available.

It also shows many have been forced to increase their initial estimates, with some of them doubling as the impact of the catastrophe becomes clear.

German reinsurance giant Munich Re increased its estimated loss figure from $906m (£637.5m) to $2.1bn (£1.5m).

In the US, Chubb Corporation increased its estimated losses from $300m (£211.1m) to between $500m (£351.8m) and $600m (£422.2m). In Italy, Generali increased its figure from $10m (£7.04m) to $20m (£14m).

Thomson's managing director for Europe, Andrew Johnson, warned figures would probably continue to increase for years to come.

He said: "A number of original estimates have been increased, some of them by 100%. Experience would point to the estimates increasing in the future, with the final magnitude not being known for several years."

The full table can be seen
here .