Aon in August 2026 confoirmed it had agreed to acquire USI Insurance Services from KKR and other shareholders in a $17 billion deal, marking its second major middle-market push in two years following the 2023 NFP acquisition. On a net basis, accounting for roughly $278 million in tax attributes, the price comes to $16.7 billion, or about 14.5 times USI’s synergized trailing-twelve-month adjusted EBITDA.

USI, the tenth-largest US insurance broker, generates approximately $3 billion in annual revenue through more than 10,500 employees across nearly 200 offices, offering property and casualty, employee benefits, personal risk and retirement plan services. Under the agreement, USI chairman and CEO Mike Sicard will become president of Aon plc and global CEO of its middle-market business, reporting to Aon CEO Greg Case.

Aon estimates the US middle market exceeds $40 billion, representing more than a third of the country’s commercial P&C premium. The company expects roughly $395 million in annual run-rate synergies once integration is complete, with the deal adding to adjusted earnings per share starting in 2028. The acquisition will be funded entirely through new debt, with Aon pausing share buybacks to preserve its credit ratings.

The transaction is one of the largest private equity exits in the brokerage sector, continuing a two-year trend of publicly traded brokers using strengthened stock valuations to acquire scale. Pending regulatory approval, the deal is expected to close in the fourth quarter of 2026, with integration—and retention of USI’s senior talent—likely to draw close industry scrutiny.