Lloyd's broker THB is set to expand its professional indemnity book after investing in new insurance broker FiSure Holdings.

The AIM-listed broking group has acquired a controlling interest in FiSure for an undisclosed sum, which was announced on Tuesday.

THB has bought 33.3% of the company's equity together with 75% of its voting rights with an option to acquire the balance of FiSure.

THB group chief executive Vic Thompson said: "This is an important acquisition for THB. It will further develop our capability in the professional indemnity area, building on the purchase of Carter-Gilbrook Insurance Services in 2005 and complementing our existing core strengths."

FiSure is a recently established London-based broker headed up by managing director Roddy Graham.

The company was formed in 2005 and specialises in professional risk and directors' and officers' insurance, particularly for international clients and the financial services industry.

Its wholly owned subsidiary FiSure already acts as an appointed representative of THB subsidiary Thompson Heath & Bond, the Lloyd's broker.