Gallagher appoints Aon’s Alistair Lester as CEO of Private Equity and M&A in UK & EMEA

Gallagher, the insurance and reinsurance broking group, has named Alistair Lester as the Chief Executive Officer (CEO) of its Private Equity and M&A client practice. Lester will be responsible for overseeing the firm’s existing transactional risks teams in the UK, Europe, and the Middle East (EMEA) and expanding the practice to offer a wide range of services and solutions for businesses engaged in acquisitions, mergers, and other transactions. He will report directly to Michael Rea, the CEO of Gallagher’s broking business in the UK.

In his new role, Lester will lead Gallagher’s transactional solutions teams in the UK & EMEA, which currently provide various solutions such as tax, warranty & indemnity, litigation, structured credit, pre-M&A due diligence, and post-deal/portfolio services. With nearly thirty years of industry experience, Lester joins Gallagher from global insurance and reinsurance broker Aon, where he served as the global co-CEO of M&A and transactional solutions for eight years. Prior to that, he worked at broker WTW, bringing extensive experience in M&A and post-deal value creation for corporate clients, private equity firms, and other alternative asset managers.

Michael Rea, the CEO of Gallagher’s broking business in the UK, expressed his confidence in Lester’s appointment, highlighting Lester’s expertise and proven track record in managing global teams and driving revenue growth. Rea emphasized that Lester will lead Gallagher’s transactional risks team across the UK Specialty division and regional hubs across Europe and the Middle East, closely collaborating with colleagues in the Americas, Australia, and Asia to develop the global Gallagher Private Equity and M&A practice. In response to his appointment, Lester recognized the growing role of risk and insurance professionals in private equity and M&A transactions, expressing excitement about working with Gallagher’s established team to expand their presence in key markets and enhance solutions and services for clients.

Furthermore, Arthur J. Gallagher & Co. reported total revenue of $3.17 billion in Q2’25, an increase from $2.73 billion in Q2’24. The core brokerage and risk management segments contributed to a 16% revenue growth, with organic revenue growth reaching 5.4%. This financial performance reflects the company’s continued success and growth in the insurance and reinsurance industry.

In conclusion, Alistair Lester’s appointment as the CEO of Gallagher’s Private Equity and M&A client practice signals the company’s commitment to providing comprehensive services and solutions to businesses engaged in transactions. With his extensive industry experience and leadership, Lester is poised to drive growth and enhance Gallagher’s offerings in key markets, underlining the company’s position as a leading player in the insurance and reinsurance sector.