Simpson Thacher, Cravath Lead Aon’s $17 Billion USI Buy From KKR
Aon Plc agreed to buy USI Insurance Services from KKR & Co. for $17 billion. Simpson Thacher advised KKR, while Cravath represented Aon. Aon is a publicly traded company (AON).
How this was made

The 30-second read
Why it matters
The transaction reshapes the insurance services landscape, affecting both acquirer and seller valuations.
Market read
Large‑scale M&A in financial services with immediate price implications for AON and KKR.
What to watch
Regulatory approvals and potential antitrust scrutiny could delay closing.
Background
The article outlines the legal teams advising Aon and KKR on the $17 billion acquisition of USI Insurance Services.
Ticker impact
Aon Plc announced it will acquire USI Insurance Services from KKR for $17 billion.
Modest price decline on announcement, followed by gradual recovery as synergies are evaluated.
Large M&A deal size and financing considerations typically cause short-term pressure, but long-term strategic fit is positive.
KKR agreed to sell USI Insurance Services to Aon for $17 billion.
Immediate price uptick on deal completion news.
Sale of a major portfolio company at a premium typically boosts investor sentiment.
Market effects
Consolidation in insurance services sector may pressure peers.
U.S. market sees increased M&A activity in financial services.
Deal highlights cross‑border M&A trends, may influence global insurers.
Counterpoint
Deal could overpay for USI, leading to integration challenges and margin pressure.
Key entities
- CompanyAon Plc
U.S.-based professional services firm acquiring USI.
- CompanyKKR & Co.
Private equity firm selling USI.
- CompanyUSI Insurance Services
Insurance services provider being sold.



