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AM Best Affirms Credit Ratings of Castle Harbour Insurance Limited and Harrington Sound Insurance Limited

OLDWICK, N.J.--(BUSINESS WIRE)--AM Best has affirmed the Financial Strength Rating of A (Excellent) and the Long-Term Issuer Credit Ratings of “a+” (Excellent) of Castle Harbour Insurance Limited (Castle Harbour) and Harrington Sound Insurance Limited (Harrington). These companies are captive insurance companies of SLB N.V. (SLB). The outlook of these Credit Ratings (ratings) is stable. Both captives are domiciled in Bermuda.

The ratings of Castle Harbour and Harrington reflect the companies’ balance sheet strength, which AM Best assesses as strongest, as well as their strong operating performance, neutral business profile and appropriate enterprise risk management (ERM).

Castle Harbour and Harrington are single-parent captives of their ultimate parent, SLB, a global technology company focused on energy innovation. Castle Harbour and Harrington maintain the strongest level of risk-adjusted capitalization, as measured by Best’s Capital Adequacy Ratio (BCAR), in addition to displaying excellent liquidity measures. The operating performance assessments of strong reflect the companies’ favorable underwriting results driven by excellent loss history and benefiting from inherently low expense structures as single-parent captives. The ratings also take into consideration the captives’ strategic importance in providing tailored insurance coverages for the parent and its subsidiaries. While each captive carries relatively large limits within its respective designated coverages for the parent in the general liability and property lines of business, each writes a broad scope of business and has considerable geographic diversification. Each captive also maintains significant retentions within the offered limits, but they are readily manageable within their respective capital bases and organic surplus growth, offset by periodic sizable dividends.

As captive insurers of SLB, the companies are an integral part of the parent’s ERM framework, which includes defined risk controls and optimization of the captives’ capital. Further, AM Best recognizes the financial flexibility afforded by their parent company, and their strategic importance across SLB.

AM Best remains the leading rating agency of alternative risk transfer entities, with more than 200 such vehicles rated in the United States and throughout the world. For current Best’s Credit Ratings and independent data on the captive and alternative risk transfer insurance market, please visit www.ambest.com/captive.

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 specializing 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

Luke Davies
Financial Analyst
+1 908 882 2467
luke.davies@ambest.com

Dan Teclaw
Director
+1 908 882 2390
daniel.teclaw@ambest.com

Christopher Sharkey
Associate Director, Public Relations
+1 908 882 2310
christopher.sharkey@ambest.com

Al Slavin
Senior Public Relations Specialist
+1 908 882 2318
al.slavin@ambest.com

AM Best


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Contacts

Luke Davies
Financial Analyst
+1 908 882 2467
luke.davies@ambest.com

Dan Teclaw
Director
+1 908 882 2390
daniel.teclaw@ambest.com

Christopher Sharkey
Associate Director, Public Relations
+1 908 882 2310
christopher.sharkey@ambest.com

Al Slavin
Senior Public Relations Specialist
+1 908 882 2318
al.slavin@ambest.com

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