Pretax profits for Wellington Underwriting jumped 244% in the year ending 31 December 2003.
Wellington said its pretax profits surged up from £33.9m in 2002 to £116.7m in its full year results.
Operating profit before exceptionals on longer-term investment jumped to £128.2m in 2003, up from £39.9m and produced a return on equity of 26%, said Wellington.
Net premiums written grew 17% to £331.2m.
It said all three of its major business interests, Syndicate 2020 at Lloyd's, Wellington Underwriting Inc and Aspen, had made significant contributions to the group's results.
Last December, Aspen Insurance Holdings Ltd was listed on the New York Stock Exchange at $22.50 per share.
Pretax profit at Wellington Underwriting Inc, its wholly owned US subsidiary, increased 56% for the full year to £9.2m.
The insurance company also said Syndicate 2020's results, in which it has a 56% interest, had improved progressively through the year, with a low level of reported losses and strong reserves for the World Trade Centre disaster auguring well for the future.
The group said the underwriting environment in 2002 and 2003 was stronger than it had been for a very long time, although it expected rates, on a weighted basis, to show some reduction in 2004 from 2003.
The company said it aimed to beat its target of 15% post tax return on a risk adjusted basis.
Wellington said it would start looking for a new chief executive as the current incumbent, Julian Avery, is set to retire in 2005.
