Converium Holding has attributed between $10m and $20m of losses to Hurricane Katrina, basing its estimate on the industry-wide loss forecasts of around $25bn.

The group has reduced its exposure in the US after a series of losses and adverse development, following claims of between $15m and $30m from flooding in Central Europe last month.

A spokeswoman for Converium said “The losses from Hurricane Katrina and the European floods are likely to add between 1.5 and 3 percentage points to Converium's combined ratio for 2005”.