Specialist underwriter Catlin celebrated its silver anniversary with a record end of year result.

The Bermuda-based insurer says penetration of new markets was the key to a record $US603 million ($679 million) profit before tax for the 2009 calendar year.

More than 40% of its underwriting income now comes from outside London, including its Sydney-based Australian operations, launched in 2004.

Catlin wrote $US3.7 billion ($4.16 billion) in gross written premium in 2009, up 8% on 2008.

CEO Stephen Catlin says market conditions are favourable to underwriters, although shaky investment markets present a constant challenge.