Thistle Insurance Services chief executive James Gerry has left the JLT-owned managing general agency.
Gerry's role was terminated after a review found duplication, and instead, Thistle chairman Adrian Gerling will now run the underwriting agency.
A spokesman for JLT said: ''His departure followed a review which identified the duplication of some important aspects of the roles of the senior management in that business area. James was previously CEO of Thistle and this role will no longer exist.
"We remain excited about the prospects for our Thistle operation and would like to thank James for his contribution towards its development and wish him well in his future endeavours.''
Asked whether his departure would result in Thistle being scaled back, the spokesman said: "There is absolutely no question of that happening."
Thistle was launched in January 2008, with Gerry as the boss.
Gerry had been the chief executive of JLT subsidiary Thistle since it began underwriting in January 2008. Last year revenues increase 11% to £37.7m. Organic growth was 6%. Trading profit was up 45% to £4.8m.
Thistle acquired Wolverhampton-based Ingham Underwriting last year. Distribution is carried out through brokers, online and affinity partners. A large chunk of the business underwrote in specialist areas, such as caravan insurance.
It was focused on high volume, low premium business with quick turnaround.
Gerry previously held roles with Dual International, Chubb and Lloyd's managing agency Brockbank over a 25 year career.