Aon expands Global ReSpecialty division with Mitchell and Rimmer appointments

Aon, the global insurance and reinsurance broking group, has announced that it has appointed both Jimmy Mitchell and Adam Rimmer as brokers within the firm’s Global ReSpecialty team, effective immediately.

Aon’s Global ReSpecialty division provides specialty reinsurance and retrocession solutions, often engaging with insurance-linked securities (ILS) and collateralized markets on behalf of their client base.

Mitchell has been appointed Vice President of Global ReSpecialty, a New York-based role. In this position he will reportedly work with clients to structure global treaty portfolios, leveraging his industry expertise and market relationships in order to broaden access to proportional reinsurance markets.

The executive has been part of Aon’s Commercial Risk team since 2025, when he joined the company after working at broker Guy Carpenter, and Willis, a business of insurance and reinsurance broker WTW.

In his new role, Mitchell will report to James Fogarty, who serves as global head of marine, energy and composite for Global ReSpecialty, operating across both Retrocession and Specialty Proportional business lines.

Meanwhile, Rimmer, who is based in London, joins Aon as a senior Property Specialty broker.

He joins the firm from parametric MGA, FloodFlash, where he was co-founder and Chief Executive Officer for eight years, having previously spent five years in the capital markets team at risk modelling firm RMS.

Rimmer brings a deep degree of technical knowledge within property reinsurance, insurance-linked securities (ILS) and parametric solutions towards his new role, all of which are skills he will leverage to advise clients on diverse risk transfer solutions.

Richard Wheeler, co-leader of Global ReSpecialty, commented: “We are excited to welcome Jimmy and Adam to our growing team to help drive better decision making for our clients.

“They represent our ongoing investments in exceptional talent and expertise to support our clients’ profitable growth and effective risk management strategies in a continuingly evolving risk landscape.”