Aon to Buy USI Insurance Services for $17 Billion in Major Brokerage Deal

Aon has agreed to acquire rival USI Insurance Services from private equity firm KKR and other shareholders for $17 billion, in one of the largest insurance brokerage acquisitions in recent years.

USI is the 10th largest insurance broker in the United States, with approximately $3 billion in annual revenue and more than 10,500 employees across nearly 200 offices, according to Aon. Its services include property and casualty insurance, employee benefits, personal risk, retirement solutions and other risk management services.

Aon said the transaction builds on its $13.4 billion acquisition of NFP in 2024, another major deal aimed at strengthening its position in the U.S. middle market.

The company said combining USI with its existing capabilities will create a stronger platform for serving middle market businesses while giving Aon greater exposure to the excess and surplus (E&S) insurance market, one of the faster growing areas of U.S. commercial insurance.

Aon expects the transaction to generate approximately $395 million in annual run-rate net adjusted EBITDA benefits from revenue and cost synergies once the businesses are combined. It also expects the deal to become accretive to adjusted earnings per share in 2028.

USI Chairman and CEO Mike Sicard will become president of Aon and global CEO of its middle market business following completion of the transaction.

KKR and Canadian pension fund CDPQ acquired USI in 2017 for approximately $4.3 billion, including debt. KKR subsequently invested more than $1 billion in the business and became its largest shareholder, Reuters reported.

At $17 billion, the sale represents a substantial increase in USI's value since KKR's original investment and highlights the strong valuations that large insurance brokerage businesses have attracted.

Reuters noted that large acquisitions have become increasingly common in the fragmented insurance brokerage industry as companies seek greater scale and stronger competitive positions.

Aon said it plans to finance the acquisition through new debt, subject to market conditions. The company expects to maintain its existing Baa2 rating from Moody's and A- rating from S&P, while prioritizing debt repayment after the transaction.

Aon also said it does not expect to repurchase shares in the near term as it focuses on reducing leverage and funding the acquisition.

The transaction has been approved by the boards of both companies but still requires regulatory approvals and other customary closing conditions. Aon expects the acquisition to close in the fourth quarter of 2026.

The acquisition gives Aon a larger platform in a market where insurance brokers can benefit from recurring revenue, scale and growing demand for risk management services.

For Aon shareholders, the key question will be whether the company can deliver the expected revenue and cost synergies while managing the additional debt required to finance the purchase.

For KKR investors, meanwhile, the transaction demonstrates the potential value of holding mature private-equity assets through longer investment periods. Reuters reported that the sale is expected to generate a substantial return for KKR on its USI investment.

The deal also underscores the continuing consolidation of the insurance brokerage industry, as major firms use acquisitions to expand their geographic reach, client base and specialist capabilities.

If completed as expected, the USI acquisition will give Aon substantially greater scale in the U.S. middle market and further strengthen its position across commercial insurance, employee benefits and risk advisory services.