Aon has signed a definitive agreement to acquire USI Insurance Services from KKR and other shareholders for $17 billion, marking one of the largest insurance brokerage transactions in recent years. The USI Insurance Acquisition underscores Aon’s strategic push into the US middle market insurance segment, a space that has attracted intensifying competition among brokers and consultants.
USI Insurance Services, headquartered in Valhalla, New York, is one of the largest insurance brokerage and consulting firms in the United States. The firm generates approximately $3 billion in annual revenue and employs more than 10,500 team members across nearly 200 US offices. USI provides property and casualty, employee benefits, personal risk, program and retirement solutions, with a strong focus on the middle market insurance space.
Aon Agrees $17 Billion USI Insurance Acquisition
The USI Insurance Acquisition has been unanimously approved by the boards of both Aon and USI. Aon plans to fund the transaction with new debt raised across a range of maturities, subject to market conditions, and expects to maintain its current credit ratings. The company has indicated it does not expect to repurchase shares in the near term as it prioritises debt repayment.
Greg Case, President and CEO of Aon, said the combination of capabilities and expertise, supported by proprietary data, analytics and technology, is essential for creating better outcomes for clients facing rising complexity. He pointed to the firm’s 3×3 Plan and Aon United strategy as having strengthened the company’s position ahead of this insurance acquisition.
Following the close, USI Chairman and CEO Mike Sicard will serve as President of Aon plc and global CEO of Middle Market, reporting to Case. Sicard described the USI Insurance Acquisition as an opportunity to accelerate momentum and unite the strengths of USI, NFP and Aon to deliver enhanced capabilities and service to middle market clients.
Deal Expands Middle Market Insurance Platform
Aon has said the acquisition will strengthen its presence in the more than $40 billion US middle market segment, which represents more than one third of US commercial property and casualty direct written premium. The transaction also expands Aon’s direct access to the Excess and Surplus segment, broadening the firm’s insurance brokerage reach. Aon has highlighted the potential for the combined data platform to support richer insights and AI-enabled solutions for clients.
The USI Insurance Acquisition follows Aon’s 2024 acquisition of NFP for approximately $13.4 billion in cash and stock, which similarly targeted the middle market insurance brokerage space. Together, these transactions reflect a sustained consolidation trend in insurance M&A, with major brokerages seeking scale and broader service offerings.
KKR originally acquired USI in 2017 alongside Canadian investment firm CDPQ for $4.3 billion including debt, and subsequently invested more than $1 billion in the business, becoming its largest shareholder.
The USI Insurance Acquisition is expected to close in the fourth quarter of 2026, subject to customary closing conditions including regulatory approvals. The transaction remains subject to these conditions and has not yet been completed.
This USI Insurance Acquisition positions Aon to compete more effectively across the full spectrum of commercial insurance, employee benefits, risk management and retirement solutions in the US middle market.


















