Swiss Re reported a 41% fall in net income, down to $1.1bn for 2005.
The reinsurer said the drop in net income was largely due to catastrophe claims of about 1.1 billion $836.6 m.
GWP fell to $23.17 bn in 2005, from $27.80 bn in the previous year.
The combined ratio for 2005 was 108.7%, compared with 97.0% for 2004.
Swiss Re said it expects its acquisition of GE Insurance Solutions to be completed about halfway through 2006. The deal will make Swiss Re the world's largest reinsurer.
