Gallagher has named Alistair Lester, a seasoned Aon executive, as chief executive officer of its Private Equity and M&A Client Practice.
In his new role, Lester will lead Gallagher’s transactional risks teams across the UK, Europe, and the Middle East. He will be responsible for expanding the firm’s suite of services for businesses involved in mergers, acquisitions, and other corporate transactions.
Lester brings extensive industry experience, having spent the past eight years at Aon, where he most recently served as global co-CEO of M&A and Transaction Solutions. His career also includes senior roles at WTW. At Gallagher, he will report directly to Michael Rea, CEO of the company’s UK broking operations.
As CEO, Lester will oversee Gallagher’s transactional solutions teams across the UK and EMEA. These teams provide a range of services, including tax insurance, warranty and indemnity cover, litigation risk management, structured credit solutions, pre-deal due diligence, and post-transaction advisory.
The appointment follows Gallagher’s recent recognition as the top litigation insurance broker in the Chambers Litigation Support Guide 2025, marking the firm’s fourth consecutive year at the top of this ranking.
The UK transactional risks market continues to evolve, driven by sustained private equity activity and the growing use of insurance products to enhance deal certainty. Warranty and indemnity insurance has become a standard feature in mid-to large-cap M&A deals, while demand for tax and contingent risk coverage is rising—particularly in complex, cross-border transactions.
