Goshawk said it expects second half losses from hurricanes and typhoons to reach $11m more than $22m it originally estimated in September.
The company said since first published the $22m figure, Hurricane Jeanne hit Florida and there have been further typhoon's in Japan, bringing its total losses to $33m.
In a pre-close statement, Goshawk said its second half results would be hit by the unusually high frequency of windstorm losses in the US and Japan.
It said it expects its dollar net asset value at the end of the year to be broadly similar to the end of 2003, which it said was "a reasonable performance in the circumstances".
