Aon Is Buying 3 Billion Dollars of Revenue With 17 Billion Dollars of Borrowed Money

The Deal Announced This Morning

Aon confirmed today that it has agreed to buy USI Insurance Services from KKR and other shareholders for 17 billion dollars in cash. The agreement was signed Sunday. The companies expect it to close in the fourth quarter.

Aon says it will fund the purchase entirely through new debt, and that it expects to remain investment grade rated afterward.

That last sentence is the whole article. A company is borrowing 17 billion dollars, in a week when the ten year Treasury has been pushing toward levels not seen since 2023 and the Federal Reserve chair spent Friday explaining why rates may need to go up, and it is promising the rating agencies that this will not impair its credit.

Whether that promise holds is a question of arithmetic, and the arithmetic is worth walking through slowly, because this is exactly the kind of decision that corporate finance teams spend their careers on.

What USI Actually Is

USI is an insurance broker. It does not underwrite anything, meaning it does not take on risk or pay claims out of its own balance sheet. It sits between businesses that need coverage and the insurance carriers that provide it, works out what a client actually needs, and takes a commission.

It is the tenth largest such broker in the United States. It generates roughly 3 billion dollars of annual revenue, employs more than 10,500 people, and operates from close to 200 offices.

Its customers are middle market companies. That term is loose, but it generally means businesses too large to buy insurance off a shelf and too small to command the attention of the giant global brokers. A regional manufacturer with 400 employees, a hospital system, a construction firm. These clients need real advice, they do not have in house risk departments, and they are not price shopping every year.

That customer profile is the reason this deal exists.

Why a Broker Is Worth Almost Six Times Its Revenue

Seventeen billion dollars for 3 billion dollars of revenue is about 5.7 times revenue. For most industries that would be an extraordinary price. For brokerage it is closer to normal, and the reason reveals what buyers are actually paying for.

A broker has almost no cost of goods sold. It carries no inventory, builds no factories, and assumes no claims risk. Its costs are people and offices. That means a large share of every incremental revenue dollar drops toward profit.

More importantly, brokerage revenue recurs. Insurance renews annually and most clients renew with the broker they already have, because switching means re-explaining the entire risk profile of your business to a stranger. Retention rates in the low to mid nineties are standard in the industry. A revenue stream that shows up every year without being resold is worth far more per dollar than one that has to be won again each quarter.

So a buyer is not paying 5.7 times this year's revenue. It is paying for a stream that is expected to persist and grow, and pricing it against that.

The Word Entirely Is Doing a Lot of Work

Companies fund acquisitions three ways. They pay cash from the balance sheet, they issue new shares, or they borrow. Most large deals mix them.

Aon chose one. All debt.

Issuing stock would have avoided the interest cost, but it would have diluted existing shareholders, meaning every current owner would hold a smaller slice of the company afterward. Management teams that believe their stock is undervalued are reluctant to use it as currency, because doing so means selling a piece of the company cheaply to buy something else.

Using debt keeps the equity intact. Every dollar of value the acquisition creates above the cost of the borrowing accrues to the existing shareholders. That is leverage working the way it is supposed to.

It also means the entire risk of the deal now sits on the balance sheet as a fixed obligation. Interest gets paid whether or not the synergies show up.

Here is the part that is worth doing on paper. Aon has not published the interest rate it will pay, and the debt has not been issued yet, so any figure is an estimate. But investment grade corporate borrowers are currently pricing new long dated debt in the general vicinity of 5.5 to 6 percent, given where Treasury yields sit and the modest spread a strong credit pays over them. On 17 billion dollars, that implies annual interest expense somewhere in the range of 935 million to roughly 1.0 billion dollars.

Treat that as an illustration rather than a disclosure. The point is the order of magnitude. Aon has committed to something close to a billion dollars a year of new interest expense, forever, in exchange for a business generating 3 billion dollars of revenue.

What 395 Million Dollars of Synergies Means

Aon says the combination will produce 395 million dollars of annual run rate net adjusted EBITDA from revenue and cost synergies.

That phrase deserves unpacking, because it is four qualifiers stacked on a number.

EBITDA is earnings before interest, taxes, depreciation, and amortization. It is a rough proxy for the cash a business throws off from operations before financing and accounting decisions. Run rate means the figure the company expects to reach eventually, annualized, not the amount it will earn next year. Net means after the costs of achieving it. Adjusted means certain items have been excluded.

Synergies come in two flavors and they are not equally believable. Cost synergies are things you can count in advance. Two headquarters become one. Duplicate finance, legal, and technology functions get consolidated. Overlapping office leases are not renewed. These usually materialize, because they are decisions the acquirer controls.

Revenue synergies are the claim that the combined company sells more than the two would have separately, because Aon can offer USI's middle market clients services USI never had, and USI's distribution can carry Aon products. These are real in principle and routinely disappointing in practice, because they require thousands of individual salespeople to change behavior.

Set the synergy number against the estimated interest cost. Roughly 395 million dollars of new EBITDA against something close to a billion dollars of new annual interest. The synergies alone do not cover the financing.

That is not a criticism. It is the structure of the deal. The synergies are the improvement. What actually services the debt is USI's existing earnings plus that improvement. The deal works if the acquired business was already comfortably profitable, and it fails if the acquired business was thinner than it looked.

Accretive in 2028 Is a Two Year Admission

Aon says the deal will be accretive to adjusted earnings per share in 2028.

Accretive means earnings per share go up. Dilutive means they go down. Every acquirer wants to announce accretion, and the year attached to the word is the most honest number in most deal announcements.

The company is telling investors that in 2027, the first full year, the interest expense and integration costs will outweigh the added earnings. Earnings per share will be lower than they would have been without the deal. Only in the second full year does the arithmetic turn positive.

That is a disclosed two year drag, and it is a reasonable one for a deal of this size. Integration takes time. Synergies phase in. Debt gets paid down. But it means shareholders are being asked to accept worse reported results for roughly eight quarters on the promise of better ones afterward, and it means management is confident enough to put a date on it in writing.

Watch that date. If it slips in a future quarterly filing, that is the earliest reliable signal that the deal is not going according to plan.

Investment Grade Is a Promise With Teeth

Aon said it expects to remain investment grade rated. This is not corporate throat clearing.

Credit ratings sort borrowers into investment grade and below, and the boundary is a cliff rather than a slope. Cross it and your borrowing costs jump. Worse, a large class of institutional investors, including many pension funds and insurance companies, are restricted by their own mandates from holding debt below investment grade. Falling below the line does not just make money more expensive, it shrinks the pool of people allowed to lend to you.

So the promise constrains behavior. To hold the rating while adding 17 billion dollars of debt, Aon will have to keep its leverage ratio, meaning total debt divided by EBITDA, inside whatever range the agencies consider acceptable. That in turn constrains what else the company can do. Buybacks get smaller. The next acquisition waits. Free cash flow goes toward paying down principal.

This is what corporate finance actually looks like from the inside. A single financing decision made in one week determines what the company is allowed to do for the next three years.

The Timing Is the Strange Part

This is the second enormous middle market acquisition Aon has made in three years. It bought NFP for 13 billion dollars in 2024. With USI, that is 30 billion dollars committed to the same strategic idea.

The idea is sound. Large corporate risk broking is a mature business with a handful of global players and limited growth. The middle market is fragmented across hundreds of regional firms, most of them founder owned and reaching succession age, and it is growing. Consolidating it is a genuine opportunity, and being the consolidator with the largest balance sheet is a genuine advantage.

The timing is the harder question. This deal was signed into a market where the Fed chair said Friday that he would be hard pressed to call financial conditions restrictive, where futures put the odds of a September rate hike above a coin flip, and where long term yields are at multiyear highs.

Corporate finance has a term for the minimum return an investment must clear to be worth doing. It is the hurdle rate, and it moves with the cost of capital. When borrowing costs rise, the hurdle rises, and deals that penciled out last year stop penciling out.

Aon is doing the opposite of waiting. That can mean two things. Either management believes USI was available now and would not be later, which is often true of a private equity owned asset with a seller ready to sell, or it believes the cost of capital is going higher still and this is the cheapest money it will see for a while.

Both are defensible. Neither is comfortable.

What KKR Got

On the other side of the table, KKR is reported to walk away with roughly 3.3 billion dollars.

That is the private equity model executed to completion. Buy a business, hold it for years, improve its operations and grow it through smaller acquisitions, then sell it to a strategic buyer who can pay more than a financial buyer would, because the strategic buyer gets synergies a financial buyer does not.

The reason Aon can pay 17 billion dollars is precisely the 395 million dollars of synergies. Another private equity firm buying USI would get none of that, so it could not justify the same price. The synergy estimate is not just a projection for investors. It is the mechanism that let the seller extract a higher number.

Every large acquisition has this structure hiding in it. The buyer's synergy case is simultaneously the justification it offers its own shareholders and the reason it had to pay what it paid.

The Bottom Line

Strip away the announcement language and this is a clean, teachable transaction. A buyer is paying 17 billion dollars for 3 billion dollars of recurring, high retention revenue, funding it with 100 percent debt, expecting close to a billion dollars a year of interest, claiming 395 million dollars of synergies, and telling shareholders the deal will hurt reported earnings until 2028.

None of those numbers are hidden. They were all disclosed on purpose, and together they let anyone outside the company build the same model management built inside it.

The two things to watch are whether that 2028 accretion date holds, and whether the investment grade rating survives contact with the actual debt issuance. If both hold, this becomes the deal that made Aon the consolidator of the American middle market. If either slips, it becomes a case study in what happens when a company borrows at the top of a rate cycle.