Aon is in the final stages of acquiring Bermuda-based captive and risk finance company International Risk Management Group (IRMG) for an undisclosed sum.
The merged group will have a premium income of £5bn.
The risk management giant said it intended to merge IRMG, which is 70% owned by Swiss Re, with its own captive management operations – Aon Insurance Managers. IRMG managers own the company's remaining 30% shareholding.
Swiss Re said it decided to divest itself of its stake in IRMG in order to concentrate on its core risk financing activities.
The new group, Aon International Risk Management Group, will be headed by Philip Stamp as chairman and chief executive.
Stamp said the merged group would enhance Aon's consulting capabilities and enable it to provide a better service.
He added: "The merger will create one of the largest captive management and captive consulting operations serving 120 counties around the world."
Aon said its newly-merged captive operations will have more than 750 clients, 400 staff and offices in all the major captive locations such as the Isle of Man and Bermuda, as well as onshore consulting operations.
Prior to the merger Aon Insurance Managers managed 550 captives and IRMG 230.
