Willis hopes to launch its Global360 sidecar in the next few weeks.

CEO Dominic Casserley told the UK Financial Times that Willis is to sign up several leading London insurers that will provide an alternative capital source to the arrangement.

Earlier this year Aon launched a co-insurance agreement with Berkshire Hathaway, in which the insurer provides capital for 7.5% of Aon-brokered retail business placed at Lloyd’s.

Aon’s Australian clients have already accessed the capacity.

Willis has not given a launch date for its sidecar or revealed whether capacity will be available locally.

GM Placement Services Maurice Gatto says the facility is unique “because it provides a stable, multi-year structure that will bring new capacity to clients, over and above that which is already available in the market, as well as driving efficiencies in market processes”.

He told insuranceNEWS.com.au Willis hopes to involve a cross-section of large and small insurers and reinsurers from around the world.

The Aon deal has prompted condemnation from some sectors of the London market, over concerns it will undermine Lloyd’s syndicates and lacks underwriting controls.

Under the schemes, brokers agree to allocate a percentage of all risk to the vehicle and the insurer/s sign up to accept a percentage of that risk.

The new model is not universally supported by all major brokers, with JLT CEO Dominic Burke telling the Financial Times the model is not sustainable.

JLT Australia and New Zealand CEO Leo Demer told insuranceNEWS.com.au that as a “client-first organisation that tailor-makes its programs to meet the clients needs”, sidecars or similar facilities “are no part of the JLT strategy at all”.