More than 20 per cent of the world’s top 50 largest reinsurers are based in Bermuda or have a significant presence here.

In a latest rankings, PartnerRe Ltd is the highest placed Bermudian-based company, appearing at 12 on the 2018 list from ratings agency AM Best. It had $6.3 billion of unaffiliated life and non-life reinsurance gross premiums written, as measured by AM Best’s methodology.

The list was released as part of a 74-page Global Reinsurance market segment report published on Thursday.

One spot below PartnerRe on the list is Everest Re Group Ltd, with similarly assessed gross premiums written totalling $6.22 billion, while at 14 is XL Bermuda Ltd with $5.21 billion unaffiliated gross premiums written, according to AM Best.

RenaissanceRe Holdings Ltd and Axis Capital Group Ltd, also make the top 20, while Arch Capital Group Ltd is at 21.

Others on the list include Tokio Millenium Re, Aspen Insurance Holdings Ltd, Validus Reinsurance Ltd, Hiscox Ltd, Chubb Ltd, and Third Point Reinsurance Ltd.

A new entry at 47 is Argo Group International Holdings Ltd, while Maiden Holdings, which had been at 40 in 2017, did not make it into the latest top 50.

In its report, AM Best called the Maiden Re result the most significant drop. It added: “The drop was driven by Maiden Re’s decision to divest all of its US treaty reinsurance operations, which no longer factor into its premium revenue.”

Swiss Re Ltd changed places with Munich Reinsurance Company to top the list with unaffiliated gross premiums written estimated by AM Best at $36.4 billion.

AM Best noted that the year-on-year growth in the top 50s total gross premiums written was close to nil, with the 2018 total at $263 billion.

There had been growth in 2017, which was driven largely by reinstatement premiums resulting from hurricane losses created by Harvey, Irma and Maria.

The combined ratio of the 2018 top 50 was 100.9, reflecting the losses sustained from US hurricanes, wildfires in California and Typhoon Jebi in Japan, however it was a substantial improvement on the collective combined ratio of 109.1 seen in 2017.

Bermuda-based reinsurers also dominated AM Best’s subgroup showing the top 15 global non-life reinsurance groups. Again using a measurement of unaffiliated gross premiums written, Everest Re, Partner Re and XL Bermuda were seven, eight and nine, respectively, on the list, with RenRe at 12, and Axis Capital and Arch Capital at 14 and 15 respectively. The list was led by Munich Re.

In introductory remarks to the report, Matt Mosher, president and chief executive officer at AM Best, said: “In December 2018, we revised our outlook for the global reinsurance segment from negative to stable.

“Reinsurers faced a challenging year in 2018 — following an even more challenging 2017. Typhoon Jebi, California wildfires, and Hurricanes Florence and Michael caused above-average insured losses even as insurers and reinsurers were hoping for a respite after 2017.”

He added: “At a recent panel discussion we held, reinsurance experts agreed that, after the natural disasters in 2017 and 2018, the reinsurance market would be more rational over the near term and that third-party capital investors would maintain their presence in the market owing to differing return expectations and lower interest rates.”

AM Best’s market segment report on global reinsurance also features commentary on trends at Lloyd’s, the mortgage market, collateralised reinsurance, Asia-Pacific, Latin America, Middle East and North Africa and sub-Saharan Africa.