Four of the world's biggest insurance brokers reported second-quarter results within nine days of each other this month, which makes for a rare like-for-like comparison. WTW and Arthur J. Gallagher both reported on 30 July, Aon the day before, and Marsh McLennan about a week earlier. On the broking side specifically, WTW came out ahead of all three.
WTW's Risk & Broking segment grew organic revenue by 7% in the quarter. Gallagher's Brokerage segment, the most directly comparable unit, grew 5%. Aon's Risk Capital solution line also worked out to around 5% organic, based on Aon's disclosure that both of its component lines, Commercial Risk and Reinsurance, grew 5%. Marsh McLennan's Risk and Insurance Services segment, which houses both Marsh's own broking arm and reinsurance broker Guy Carpenter, grew just 3% organically, dragged down by a 2% decline at Guy Carpenter as softer reinsurance pricing bit. Strip out reinsurance and look at Marsh's core broking business alone, and it managed 4% organic growth, still three points behind WTW.
Gallagher's own headline growth figure looks even better than 5%, its "combined" Brokerage and Risk Management segments grew organic revenue by 6%, a figure chairman and CEO Pat Gallagher highlighted in the company's earnings release. But that blended figure leans heavily on Gallagher Bassett, the group's third-party claims administration business, which posted 12% organic growth this quarter. Gallagher Bassett is a claims and risk-management services operation, not a broking or placement business, so it isn't really measuring the same thing as WTW's Risk & Broking, Aon's Risk Capital or Marsh's broking arms. On the narrower, more comparable measure, Brokerage alone, Gallagher's 5% still trails WTW's 7%.
That's a genuinely strong quarter for WTW's core broking business. You would not necessarily guess it from the group's headline profit figures, which fell sharply on a reported basis.
WTW's net income fell 30% year-on-year to $231m, and reported diluted earnings per share dropped 27% to $2.43. On the adjusted measures that strip out one-off items, the picture reverses entirely: adjusted diluted EPS rose 17% to $3.35, and adjusted operating margin expanded 100 basis points to 19.5%. Two things explain almost all of the gap. Transaction and integration costs tied largely to the Newfront acquisition, which WTW closed in January, jumped from $2m in the same quarter last year to $61m this quarter. On top of that, last year's comparable quarter benefited from a one-off $74m favourable tax item that flattered the 2025 baseline, making this year's comparison look worse than the underlying trend really is.
Gallagher shows a strikingly similar pattern for the same underlying reason: a large, still-being-integrated acquisition. Its reported net earnings fell 12% to $324m and reported diluted EPS fell 11% to $1.25, while adjusted diluted EPS rose 23% to $2.84. The gap is driven by the ongoing integration of AssuredPartners, the roughly $14bn acquisition Gallagher closed in August 2025, its largest ever. Acquisition integration costs in Gallagher's Brokerage segment jumped from $30m to $84m year-on-year, and amortisation of acquired intangibles rose from $130m to $218m, an increase of nearly 70%. Gallagher's comparison is also flattered in reverse by a prior-year item: roughly $144m of interest income earned in Q2 2025 on cash raised for the AssuredPartners deal before it closed, income that naturally disappeared once that cash was spent on the acquisition.
Aon and Marsh show a much smaller version of the same reported-versus-adjusted gap, and in Aon's case, none of the same direction problem. Aon's GAAP operating margin rose 80 basis points to 21.5% in the quarter, while its adjusted margin rose a similar 70 basis points to 28.9%, both figures moving the same way. Marsh shows a milder version of the WTW/Gallagher pattern: GAAP EPS of $2.63 trailed adjusted EPS of $2.96, but both were still up on the prior year, just not by the same margin. WTW and Gallagher are the two brokers this quarter where the headline and adjusted trends actively disagree about which way the business is moving, and in both cases the explanation is the same: a transformative acquisition still working its way through the numbers.
None of this means WTW's or Gallagher's headline numbers are fake, or that integration costs don't matter. $61m and $84m respectively are real cash spent this quarter, and both will recur for as long as their acquisitions continue to be absorbed. But if the question is which of the four brokers grew its core placement business fastest this quarter, on a comparable segment basis, the answer is WTW, ahead of Gallagher and Aon, and by a wider margin over Marsh. That's a harder number to spin than a profit figure, and precisely the one currently buried under the accounting noise of two major acquisitions.
