Allianz Cornhill is setting up a team in The Broker Network's (BNL) Underwriting Room from September 1.
Insurers Axa and Hiscox are already located in the room, with more set to follow later in the year.
The network was set up in 1995, intended to be an umbrella organisation for insurance intermediaries. The Underwriting Room itself was launched at the beginning of the year.
Peter Moran, regional manager for Allianz Cornhill said: "Our strategy to join BNL's Underwriting Room creates an excellent synergy to our own ongoing development. It is very clear that numerous benefits will be created."