By Chad Hemenway | August 31, 2026
Aon plc early Monday confirmed a definite agreement to buy USI Insurance Services from private equity firm KKR for $17 billion.
Aon said the deal bolsters its goal to target the U.S. middle market segment, building upon its 2024 acquisition of NFP for $13 billion. The acquisition gives Aon expanded direct access to the excess & surplus market through MGAs and MGUs with USI’s wholesale capabilities.
The deal was first reported Sunday by the Wall Street Journal.
“Combining with USI will establish the premier U.S. middle-market platform, deepen our context advantage and position Aon to accelerate organic growth,” said Greg Case, president and CEO of Aon, in a statement. ” Building on the success of our acquisition of NFP, USI will substantially enhance our middle-market footprint and expand access for our firm in the E&S segment to deliver content, capabilities and expertise to a broader client base, while enabling client leaders to expand relationships and win new business.”
Aon said USI Chairman and CEO Mike Sicard will serve as president of Aon plc and global CEO of Middle Market once the deal is closed, which is expected to occur during the fourth quarter 2026. The boards of each company have approved the deal, and the brokers will continue to operate separately until the closing date, Aon said.
Aon said it will fund the transaction and related transaction expenses with new debt.
Valhalla, New York-based USI is the tenth largest U.S. insurance broker with about $3 billion in annual revenue. The brokerage has about 200 offices in the U.S., with a combined 10,500 employees. Its USI One analytics platform was clearly coveted by Aon, with Case adding that the combined Aon and USI platforms will “generate richer insight, advance the development of innovative, AI-driven solutions and expand the universe of insurable risk, while further reinforcing the context advantage that differentiates Aon.”
KKR and Canadian pension fund Caisse de dépôt et placement du Québec in 2017 agreed to buy brokerage USI Insurance Services from Onex Corp. in a $4.3 billion deal. In 2023, KKR invested an additional $1 billion in USI to become its largest shareholder.
Aon said it expects to deliver about $395 million in annual run-rate net adjusted EDITDA from revenue and cost synergies from the deal. Aon is the third-largest broker in the U.S., behind Marsh and Arthur J. Gallagher, with about $8.15 billion in revenue.
Written ByChad Hemenway
Chad is National News Editor at Insurance Journal. He has been a journalist since 2000, with a focus on the insurance industry since 2007, reporting on trends and coverage in most lines of insurance as well as natural catastrophes, modeling, regulation, legislation, and litigation. Chad can be reached at chemenway@wellsmedia.com