Swiss Re, Munich Re and Hannover Re Top List of 40 Largest Reinsurers in 2025: S&P

Swiss Re tops the list of the world’s 40 largest reinsurers in 2025, followed by Munich Re and Hannover Re, according to S&P Global Ratings.

Berkshire Hathaway Insurance Group comes in at number four, while Lloyd’s is ranked at number five and SCOR is number six. (See chart below for the full top 40 list).

For the purposes of developing the top 40 ranking of global reinsurers and overcoming the issue of comparing reinsurers that report under the GAAP versus IFRS 17 accounting standards, the ratings agency referred to gross premium written (GPW) for pure reinsurance business.

“For those reinsurers reporting under IFRS 17 and that do not publish GPW, we estimated the pure reinsurance GPW and marked them in the ranking. At the same time, we added the gross insurance revenue for reinsurance for all IFRS 17 filers,” said S&P in its report titled “S&P Global Ratings’ Top 40 Global Reinsurers In 2025 And Reinsurers By Country,” published on Sept. 3.

One of the main challenges for creating this report, S&P said, was drawing a clear line between companies’ reinsurance and primary insurance activities, “especially in cases where the reinsurance operation is a division within a company and not a distinct business.”

“Generally, premium data relate to a company’s reinsurance premium written. In some cases, however, other metrics include data from the primary insurance and the reinsurance business. If we did not view the metrics provided by companies as representative of their reinsurance operations, we marked the relevant metrics as not available (N.A.).”

Further, for groups that write both non-life and life reinsurance businesses, the combined ratio reflects non-life business only.

The report also breaks down the top reinsurers by country.

(Click on the graphic below to expand the Top 40 list)