Chaucer has contracted a specialist underwriting agency to handle motorcycle business placed by the majority of its agency holders.
Ten brokers place around 88% of Chaucer's motorcycle business, said Chaucer chief executive Ewen Gilmour.
Motorcycle business placed by about 2,000 other brokers will be handled by underwriting agency Novitas.
Chaucer personal lines divisional underwriting director Chris Dixon said: "What we are seeing is that the amount of business that we get from these brokers is relatively small so it seems logical that we pass it over to people who can spend more time with them.
"If we see that we are getting more business from them we would review the situation but the current intention is to have them go through Novitas."