A.M. Best Co. has assigned a financial strength rating of A (Excellent) and issuer credit rating of “a+” to Essentia Insurance Company (Essentia) (Chesterfield, MO). The outlook assigned to both ratings is stable. The ratings largely reflect the full rating enhancement afforded to Essentia given its recent acquisition by Markel Corporation (Markel) (Glen Allen, VA) [NYSE: MKL] and the implicit as well as explicit support provided to Essentia by an affiliate, Evanston Insurance Company (Evanston) (Deerfield, IL), in the form of a 100% whole account quota share reinsurance agreement. Effective January 2, 2013, Essentia was acquired by Markel from OneBeacon Insurance Group, Ltd. (OneBeacon) (Bermuda) [NYSE: OB]. Prior to the purchase, all prior-year liabilities were 100% reinsured by a OneBeacon subsidiary. Historically, Essentia ceded the majority of its business to OneBeacon Insurance Company. Essentia will continue to underwrite insurance exclusively for the Hagerty Insurance Agency and the Hagerty Classic Marine Insurance Agency (collectively known as Hagerty) throughout the United States. Hagerty is the leading insurance provider in the world for classic vehicles and host to the largest network of classic car owners. Through Hagerty, Essentia offers insurance for classic cars, vintage boats, motorcycles and related automotive collectibles. Any upward or downward revision in the ratings largely would be dependent on the ratings of Evanston. Negative rating actions also could result from lessening of support (implied or explicit) provided to Essentia by Markel and Evanston. The methodology used in determining these ratings is Best’s Credit Rating Methodology, which provides a comprehensive explanation of A.M. Best’s rating process and contains the different rating criteria employed in the rating process. Best’s Credit Rating Methodology can be found at www.ambest.com/ratings/methodology. Founded in 1899, A.M. Best Company is the world's oldest and most authoritative insurance rating and information source. For more information, visit www.ambest.com. Copyright © 2013 by A.M. Best Company, Inc. ALL RIGHTS RESERVED.