Norwich Union is to double the amount of business written through onsite underwriters in broker's offices within the next three years.

The insurer currently writes about £360m gross written premium through NU Bonus and is aiming to grow that to £700m by the end of 2008.

Director of IB specialist business Susan Adcock said approximately 30 new Bonus underwriters will be recruited both internally and externally from June, with a review on further recruitment towards the end of the year. NU currently has 450 Bonus underwriters nationally.

She said brokers with Bonus underwriters on site will benefit from better pricing to give them advantage over other brokers and encourage use of the facility.

Products from NU's small business range will be added to the NU scheme for new business in July, with renewals accepted from October, she added.

Products for more complex risks will be placed on the system towards the end of the year.

Bonus will also be moved from its current technology system to the main NU platform, which Adcock said would provide increased efficiency, allowing underwriters more business time.

"There will be improvements to the technical enablement of Bonus and improvement of access to strategic commercial product sets," said Adcock. She added that the insurer had developed a plan for "controlled growth" of the facility.