Marsh & McLennan Cos. Inc.'s pending $5.51 billion acquisition of U.K.-based insurance broker Jardine Lloyd Thompson Group PLC was by far the biggest deal involving a U.S.-based insurance company announced in the third quarter and the third-largest insurance deal announced thus far in 2018.

With this deal, Marsh & McLennan will expand its specialty risk brokerage business and widen its exposure to the U.K. The company's annual revenues are projected to grow by more than 20% following the acquisition.

When conducting this analysis, S&P Global Market Intelligence examined whole, minority and asset deals where the buyers, targets or sellers were based in the U.S., Canada or Bermuda.

Overall, there were 150 insurance broker deals announced in the third quarter, down from 158 in the second quarter, but up from 135 in the year-ago quarter.

Of the 16 insurance M&A transactions that had disclosed deal values announced in the quarter, five were valued at more than $1 billion. Overall, there have been 12 insurance deals of more than $1 billion announced this year.

Apollo Global Management LLC announced in late August that it would acquire Bermuda-based Aspen Insurance Holdings Ltd. for $2.60 billion in the second-largest deal of the third quarter. Aspen only agreed to the deal after Apollo twice revised its initial $40-per-share bid.

Of the insurance sub-industries examined in this analysis, the property and casualty sector was the only segment to see both volume and deal value gains quarter over quarter and year over year. During the third quarter, 94 P&C deals worth a combined $13.11 billion were announced, up from 75 announced deals worth a combined $920 million in the previous quarter and 78 deals worth an aggregate $4.95 billion in the year-ago quarter.

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