Aon to Buy USI Insurance Services From KKR in $17 Billion Deal
Aon has agreed to buy USI Insurance Services from KKR for about $17 billion. The deal is set to strengthen Aon’s scale and position in the global insurance brokerage industry.
Aon is set to acquire KKR-backed USI Insurance Services in a $17 billion deal. The transaction will significantly expand Aon’s presence in the US insurance brokerage market.
USI Insurance: Aon Plc confirmed on Monday, August 31, that it has agreed to acquire USI Insurance Services from private equity firm KKR & Co. in an all-cash transaction valued at approximately $17 billion, including debt. The deal, unanimously approved by the boards of both companies, was signed on August 30, according to a regulatory filing, and is expected to close in the fourth quarter of 2026, subject to regulatory approvals.
The purchase price stands at $16.7 billion on a net basis, reflecting approximately $278 million of certain tax attributes, according to Aon’s announcement.
USI Insurance: What the deal involves
USI, headquartered in Valhalla, New York, is one of the largest insurance brokerage and consulting firms in the United States, offering property and casualty, employee benefits, personal risk, program and retirement services. Founded in 1994, the firm has grown from a single office into the 10th-largest U.S. insurance brokerage, connecting more than 10,500 professionals across nearly 200 offices, and generates approximately $3 billion in annual revenue.
Aon said the acquisition would establish what it called the “premier” platform in the U.S. middle-market segment, a category the company estimates at more than $40 billion and which represents more than one-third of U.S. commercial property and casualty direct written premium. The deal builds on Aon’s 2024 acquisition of middle-market broker NFP, valued at approximately $13.4 billion, and is intended to extend Aon’s reach across health, talent and human capital advisory offerings.
The transaction also expands Aon’s direct access to the excess & surplus (E&S) segment, distributed through managing general agents, managing general underwriters and wholesalers, which Aon described as among the fastest-growing areas of U.S. commercial insurance.
“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. “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.”
Also Read: Aon Nears $17 Billion Deal for KKR-Backed USI Insurance
USI Insurance: KKR’s exit and ownership history
KKR, together with Canadian pension fund Caisse de dépôt et placement du Québec (CDPQ), originally took USI private in a $4.3 billion transaction in 2014. KKR subsequently made additional investments of more than $1 billion in the business, becoming its largest shareholder.
According to KKR, the exit delivers approximately six times its return on a follow-on 2017 investment and a 3.4 times return on capital across the full life of its USI position. The sale adds to a broader pickup in exit activity for the private equity firm, which recorded its largest monetisation quarter in history in the three months ended June, including the sales of data-center cooling firm CoolIT and Circor’s commercial and defense aerospace business.
BofA Securities and Citi served as financial advisors to Aon, with Cravath, Swaine & Moore LLP acting as legal counsel and McDermott Will & Schulte LLP advising on regulatory matters; Skadden, Arps, Slate, Meagher & Flom is acting as financing counsel to Aon. KKR was advised by Goldman Sachs, Insurance Advisory Partners and Morgan Stanley.
USI Insurance: Market and industry context
Aon shares fell between 1.5% and 1.8% in premarket trading on Monday following the announcement, with the market’s cautious reaction centred on financing: Aon said it plans to fund the entire transaction with new debt and does not expect to repurchase shares in the near term as it prioritises debt repayment.
The stock had closed at $355.40 on Friday, within its 52-week range of $323.73 to $412.97, and remains roughly flat for the year to date. Aon’s market capitalisation stood at approximately $75-76 billion ahead of Monday’s session. The deal is Aon’s second major acquisition of a private-equity-backed financial services firm in roughly two years, following its 2024 purchase of NFP Corp. from Madison Dearborn Partners and HPS Investment Partners. Madison Dearborn subsequently acquired the bulk of Aon’s NFP wealth business, including Wealthspire Advisors, for approximately $2.7 billion in 2025.
Mega buyouts have become increasingly common in the fragmented insurance brokerage industry as firms compete for market presence and competitive edge. Other recent large deals in the sector include Arthur J. Gallagher’s $13.5 billion acquisition of AssuredPartners and Brown & Brown’s near-$10 billion purchase of Accession Risk Management, both finalised last year.
Aon operates in more than 120 countries and reported second-quarter adjusted earnings of $3.81 per share on July 29, ahead of Wall Street estimates. The USI acquisition is expected to be accretive to earnings as early as 2028.
