Chaucer said net profit fell to £23.5m for the first half of 2006 against £35.8m for the same period in 2005.
Chaucer's gross written premiums increased by 26% to £331.8m.
But the specialist Lloyd's insurer's combined ratio declined from 80.9% to 85%.
Ewen Gilmour, Chaucer's chief executive, commented: “Our first half performance provides a strong base from which we aim to achieve another good full year return as we benefit from greater business volumes and reduced Gulf exposures.”
Gilmour added: “I am delighted with Chaucer's progress to date and am confident this will be further enhanced in 2007 by a good underwriting environment, our growing capacity base and continuing initiatives to build the business."
