Aon plc has signed a definitive agreement to acquire USI from KKR and other shareholders for $17 billion, a deal the companies say will create the leading platform in the U.S. middle-market insurance segment.
The transaction builds on Aon’s 2024 acquisition of NFP. USI is the tenth-largest U.S. insurance broker, with about $3 billion in annual revenue, more than 10,500 employees and nearly 200 offices across the United States. The company provides property and casualty, employee benefit, personal risk and retirement solutions, largely through its USI ONE platform.
“In a time of rising complexity and volatility, creating better outcomes for clients across their risk and people challenges requires a combination of capabilities and expertise supported by proprietary data, analytics and technology,” said Greg Case, president and CEO of Aon.
“Combining with USI will establish the premier U.S. middle-market platform, deepen our context advantage and position Aon to accelerate organic growth,” Case said. “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.”
Once the deal closes, USI chairman and CEO Mike Sicard will become president of Aon plc and global CEO of Middle Market, reporting to Case and joining the Aon executive committee.
“Joining Aon represents a truly energizing next chapter for our firm and an opportunity to accelerate our momentum as part of the Aon United platform,” said Sicard. “Our firms share strong, one-firm cultures with a deep commitment to working together to bring the best of our capabilities to clients. I look forward to leading Aon’s middle-market platform and uniting the strengths of USI, NFP and Aon to deliver a new standard of content, capabilities and service to our clients.”
The U.S. middle-market segment is worth more than $40 billion and accounts for more than a third of U.S. commercial property and casualty premiums, according to Aon. The deal also gives Aon direct access to the excess and surplus segment, which the company says makes up 26 per cent of U.S. commercial property and casualty premiums and is among the fastest-growing parts of the industry.
Aon expects the combined middle-market platform to generate $395 million in annual run-rate net adjusted EBITDA impact from revenue and cost synergies. The company said the deal should add to adjusted earnings per share starting in 2028.
The purchase price works out to $16.7 billion on a net basis, after accounting for about $278 million in tax attributes, which Aon says represents roughly 14.5 times synergized trailing twelve-month adjusted EBITDA. Aon plans to fund the acquisition and related costs through new debt across a range of maturities, subject to market conditions.
The company said it expects to maintain its current credit ratings of Baa2 with Moody’s and A- with S&P, and will keep prioritizing debt repayment, dividends and growth investments over share buybacks in the near term. Aon does not expect to repurchase shares while it works to pay down debt from the deal.
Boards of directors at both Aon and USI have unanimously approved the transaction. Closing is subject to regulatory approvals and other customary conditions, with the companies expecting the deal to close in the fourth quarter of 2026. Aon and USI will continue to operate independently until then.
Aon held a conference call on the morning of Aug. 31 to discuss the transaction with investors.
