Aon Agrees to Buy USI Insurance from KKR for $17 Billion in All-Cash Deal to Dominate Middle Market

Aon plc announced Monday it will acquire USI Insurance Services from private-equity firm KKR and its co-investors in an all-cash transaction valued at approximately $17 billion, or $16.7 billion net of certain tax attributes. The deal, to be financed through new debt, is expected to close in the fourth quarter of 2026, subject to regulatory approvals. USI, which generates roughly $3 billion in annual revenue providing risk management, employee benefits, and retirement consulting services, was KKR's first core private equity investment and has been held in KKR's Strategic Holdings portfolio since 2017.

Aon CEO Greg Case framed the acquisition as a bid to build what he called the "premier U.S. middle-market platform," and described it as potentially the greatest value-creation opportunity of his career. Aon laid out estimated integration costs and synergies on an analyst call held the same morning, though specific synergy figures were not disclosed across the available sources.

Aon shares dropped sharply on the news, falling roughly 8.8% to 10% during Monday's session and crossing below their 200-day moving average of $337.85, touching an intraday low of $321.96. The stock had been down about 1.8% in pre-market trading before the formal announcement. S&P Global cut its outlook on Aon to negative, citing the debt load the company is taking on to fund the all-cash deal, while Moody's affirmed Aon's existing rating but also shifted its outlook. UBS reiterated its rating on Aon without a change. Some analysts and market observers flagged caution given the scale of the acquisition and the leverage required to complete it.