Thomas, Carroll Brokers has increased its income by 67% over the past three years, after targeting corporate accounts worth £50,000 and more.
The broker, which is the largest independent insurance broker in Wales, reported a 10.6% increase in turnover and a 43% increase in pre-tax profits in the year to 30 September 2002.
Managing director Stuart Love said figures for the most recent financial year were nearly complete.
He said income had increased 67% in three years and 30% in the past 12 months.
"We've raised our sights to the corporate account of £50,000 and above and we've targeted that very successfully in the past 12 months."
He said the broker's small business account had grown by 19% in the past year with the corporate account up by about 30%.
Premium income now totalled £18m, with £15m from commercial business and £3m from personal lines, Love said.
But Love said he was not targeting growth at the cost of a healthy bottom line.
He said: "Being the biggest doesn't interest me. Being the best does."