AM Best Places Credit Ratings of Sompo Japan Insurance Inc. and Its Subsidiaries Under Review With Positive Implications

HONG KONG–(BUSINESS WIRE)–#insurance—AM Best has placed under review with positive implications the Financial Strength Rating (FSR) of A+ (Superior) and the Long-Term Issuer Credit Ratings (Long-Term ICR) of “aa-” (Superior) of Sompo Japan Insurance Inc. (SJ) (Japan) and its subsidiaries. Concurrently, AM Best has placed under review with positive implications the Long-Term ICR of “a-” (Excellent) of Sompo International Holdings Ltd. (SIH) (Pembroke, Bermuda). In addition, AM Best has placed under review with positive implications the Long-Term Issue Credit Rating of “a-” (Excellent) on $335 million 7% senior unsecured notes due by 2034, which is guaranteed by SIH.

These Credit Rating (rating) actions follow the announcement on 27 August 2025, that SOMPO Holdings, Inc., via a wholly owned subsidiary of SIH, has entered into a definitive merger agreement to acquire 100% of the issued Class A ordinary shares of Aspen Insurance Holdings Limited (Aspen) for approximately USD 3.5 billion in an all-cash transaction. Upon completion, Aspen will become a subsidiary of SIH, the intermediate holding company under SJ.

The under review with positive implications status reflects the potential material benefits in Sompo group’s business profile following the acquisition of Aspen, which could accelerate the geographic diversification and lead to a significant enhancement in its presence in the global property/casualty (re)insurance market. Aspen is a global (re)insurance player with a diversified underwriting portfolio and expertise in specialty lines.

The transaction is anticipated to close in the first half of 2026, subject to regulatory approvals. The ratings will remain under review with positive implications pending the completion of the transaction and until AM Best can evaluate fully the impact on SJ’s rating fundamentals.

The FSR of A+ (Superior) and the Long-Term ICRs of “aa-” (Superior) have been placed under review with positive implications for Sompo Japan Insurance Inc. and the following subsidiaries:

• Endurance Assurance Corporation
• Endurance Specialty Insurance Limited
• Endurance Worldwide Insurance Limited
• Endurance American Specialty Insurance Company
• Endurance American Insurance Company
• Endurance Risk Solutions Assurance Co.
• American Agri-Business Insurance Company
• Sompo America Insurance Company
• Sompo America Fire & Marine Insurance Company
• Lexon Insurance Company
• Bond Safeguard Insurance Company
• SI Insurance (Europe), SA

Ratings are communicated to rated entities prior to publication. Unless stated otherwise, the ratings were not amended subsequent to that communication.

This press release relates to Credit Ratings that have been published on AM Best’s website. For all rating information relating to the release and pertinent disclosures, including details of the office responsible for issuing each of the individual ratings referenced in this release, please see AM Best’s Recent Rating Activity web page. For additional information regarding the use and limitations of Credit Rating opinions, please view Guide to Best’s Credit Ratings. For information on the proper use of Best’s Credit Ratings, Best’s Performance Assessments, Best’s Preliminary Credit Assessments and AM Best press releases, please view Guide to Proper Use of Best’s Ratings & Assessments.

AM Best is a global credit rating agency, news publisher and data analytics provider specialising in the insurance industry. Headquartered in the United States, the company does business in over 100 countries with regional offices in London, Amsterdam, Dubai, Hong Kong, Singapore and Mexico City. For more information, visit www.ambest.com.

Copyright © 2025 by A.M. Best Rating Services, Inc. and/or its affiliates. ALL RIGHTS RESERVED.

Contacts

Charles Chiang
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Patrick Cyphers
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Al Slavin
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