Aon Buys Rival USI From KKR in $17 Billion Insurance Deal

Aon will acquire USI Insurance Services from KKR for $17 billion in new debt, aiming to build the premier US middle-market insurance platform.

Aon announced Monday that it will acquire USI Insurance Services, the tenth largest US insurance broker, from private equity firm KKR. The $17 billion transaction will be funded with new debt and is anticipated to close in the fourth quarter, subject to regulatory approvals. USI brings more than $3 billion in annual revenue and more than 10,500 employees. Once the deal closes, USI CEO Mike Sicard will transition to become Aon's president and global CEO of middle market, a structure that signals how central the acquired franchise is to Aon's plans.

Aon CEO Greg Case told CNBC's Squawk Box that the merger will establish the "premier U.S. middle-market platform" and let the firm serve 200,000 middle-market companies and their 48 million employees. He called the shareholder value potential "maybe the greatest I've seen in my 20-year career as CEO." Piper Sandler insurance analyst Paul Newsome explained the appeal in an email, saying middle-market commercial insurance generally grows a percentage or two faster than large-account commercial business, so shifting the business mix could lift organic growth rates. The purchase also builds on Aon's 2024 acquisition of NFP, another middle-market-focused broker.

Shares of Aon tumbled about 7% on Monday in response to the announcement, even as Case argued the deal creates tremendous value potential for shareholders. The move lands amid accelerating consolidation in the insurance brokerage industry, as Reuters coverage via TradingView framed it. KKR partner Chris Harrington said in the press release that Aon is the ideal partner to support USI's next growth chapter, and Sicard described joining Aon as an energizing opportunity to accelerate momentum on the Aon United platform.

The same day, Eli Lilly showed that corporate M&A appetite extends well beyond insurance. According to BioSpace, Lilly will pay up to $2.875 billion in cash — upfront plus contingent milestones — to acquire Massachusetts-based Merida Biosciences, gaining a Phase 1 therapy called MER511 for thyroid eye disease and Graves' disease, a preclinical allergy antibody called MER769, and Merida's precision degradation platform. BioSpace notes the deal is Lilly's latest in a busy year that has included more than $25 billion in business development spending through June, plus recent takeovers of AtaiBeckley, Centessa, and Kelonia.

Both transactions face the same immediate hurdle: regulatory clearances with fourth-quarter closings targeted. For Aon, integration will be watched closely after the initial 7% share decline, with investors assessing whether the debt-funded purchase can genuinely lift organic growth in the faster-growing middle-market segment, as analysts like Piper Sandler's Paul Newsome suggest is the goal. At Lilly, executives including Francisco Ramírez-Valle, senior vice president of immunology research and early clinical development, say they see potential to apply Merida's precision approach across a broad range of antibody-driven diseases, making early clinical readouts for MER511 worth tracking.