Aon Closing In on $17 Billion Deal to Buy USI Insurance from KKR

Aon Plc is close to a deal to buy insurance brokerage USI Insurance Services from KKR for about $17 billion, including debt, The Wall Street Journal reported Sunday, citing people familiar with the matter. CNBC and Reuters both picked up the report, and an announcement could land as soon as Monday, August 31, if negotiations close out successfully.

Nothing is finalized yet. Reuters said it could not immediately verify the Journal's reporting, and Aon, USI and KKR either could not be reached or declined to comment when Reuters asked.

Who's involved

USI is based in Valhalla, New York, and specializes in risk management, employee benefits and retirement consulting. According to Business Insurance's brokerage directory, USI pulled in $2.89 billion in brokerage revenue in 2025, split roughly 44% employee benefits, 44% retail, 5% personal lines and 4% wholesale. It employs nearly 11,000 people and ranks as the 10th-largest brokerage of U.S. business, per Business Insurance's data.

Aon is much bigger. It's the world's second-largest insurance brokerage, with $16.99 billion in 2025 brokerage revenue, trailing only Marsh McLennan's $26.66 billion, according to Business Insurance. CNBC pegs Aon's current market capitalization at $75 billion.

KKR's exit

KKR's relationship with USI goes back to 2017, when the private equity firm and Canadian pension fund Caisse de dépôt et placement du Québec bought USI from Onex Corporation for $4.3 billion including debt, according to Reuters. KKR has since poured in more than $1 billion in additional investment, becoming USI's largest shareholder by 2023, CNBC reported.

A sale to Aon would be the latest in a run of big exits for KKR this year. The firm has already sold data-center cooling business CoolIT and the commercial and defense aerospace unit of industrial manufacturer Circor, according to both CNBC and Reuters. KKR reported a record $1.29 billion in asset sales for the quarter ending in June, CNBC noted.

Private equity firms make money buying companies, fixing them up, and selling them at a profit years later. KKR turning a roughly $4.3 billion 2017 purchase into a deal valuing USI near $17 billion, even accounting for debt and additional capital KKR put in along the way, is exactly what the leveraged-buyout model is supposed to produce. Critics of private equity sometimes argue these firms load up companies with debt and strip value for short-term gain. Whatever the merits of that broader critique, nothing in the reporting here suggests USI was hollowed out. It grew into a top-10 U.S. brokerage under KKR's ownership, and the deal is reportedly expected to boost Aon's own earnings per share as soon as 2028, according to the Journal's sourcing cited by CNBC.

What Aon gets

The deal would extend Aon's reach into midsize businesses, a segment the Journal's sources say USI strengthens, according to CNBC. Aon's most recent earnings, reported July 29, came in at $3.81 per share on an adjusted basis, beating Wall Street estimates. Despite that beat, Aon's stock has fallen 5.6% since, closing at $355.40 on Friday, August 28, according to CNBC.

That stock slide happened before any USI deal was reported, so it isn't a market reaction to this specific transaction. It's a separate data point about how investors have priced Aon's shares since its last earnings report, and it will be worth watching whether that trend reverses once a USI deal, if any, is formally announced.

What's still unconfirmed

The deal size, timing and even whether it closes at all remain reported-but-unconfirmed as of Sunday. Reuters explicitly flagged that it could not verify the Journal's account independently, and none of the three companies involved has gone on record. If the deal is announced Monday as the Journal's sources predict, regulators and Aon's competitors, particularly Marsh McLennan, will need to respond to further consolidation at the top of the U.S. insurance brokerage industry.