Hannover Re is expecting a fall in profits following the impact of Hurricane Katrina.
It also expects a net loss of €250m (£170m) before tax from the hurricane.
The reinsurer said it is expecting a full-year net profit of “at least” year's level of €309.1m, substantially less than the previous forecasts of €430m to €470m.
Hannover Re chief executive Wilhelm Zeller said: “In view of the extraordinarily heavy burden of losses this is a very good performance”.