The Davis Group's profits increased by 82% in the six months to 30 April.
The broker, which specialises in transport and associated risks, made £1.02m profit before tax for the six months to 30 April compared to £560,000 in the same period last year.
Turnover for the year to date increased by 45%, it announced.
The Newmarket-based company achieved its growth organically.
Chief executive Leigh Davis Smart said: "2003 results so far show excellent income growth throughout the group, withoutany acquisitions.
"The liability and marine wholesale divisions, Davis Schemes and Davis Specialist Risks continue to exceed expectations now represent 40% of overall turnover.
"Group premium for 2003 should now exceed £40m."