Aon to Acquire USI Insurance Services in $17 Billion Deal from KKR

Aon said on Monday it will buy rival USI Insurance Services in a US$17 billion deal from private equity firm KKR, marking one of the largest insurance brokerage transactions in recent years. The acquisition is expected to close in the fourth quarter of 2026 and is anticipated to boost Aon's adjusted profit in 2028.

The deal underscores Aon's push to expand in the S. middle-market insurance segment, which serves mid-sized businesses and is estimated at more than $40 billion. Aon CEO Greg Case said the combination "will establish the premier S. middle-market platform, deepen our context advantage and position Aon to accelerate organic growth." He added that "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 (excess & surplus) segment."

USI, founded in 1994, is an insurance brokerage and consulting firm based in Valhalla, New York. It offers property and casualty, employee benefits, personal risk, program and retirement services, and generates about $3 billion in annual revenue. Under KKR's ownership, the firm nearly tripled its revenue, according to KKR.

The acquisition builds on Aon's $13 billion purchase of NFP in 2024. Aon, which caters to clients in over 120 countries, expects to fund the deal through debt. USI CEO Mike Sicard will serve as Aon's president and global CEO of its middle-market segment.

For KKR, the transaction adds to a pickup in exit activity. The second quarter was the largest monetization quarter in its history, and the USI deal is expected to generate roughly $2 billion of adjusted profit for KKR. KKR said the sale represents about six times return on its 2017 investment and a 3.4 times return on the capital invested over the life of its investment in USI.

BofA Securities and Citi advised Aon on the deal, while Goldman Sachs, Insurance Advisory Partners and Morgan Stanley advised KKR.