A.M. Best has affirmed the financial strength rating (FSR) of A (Excellent) and the issuer credit ratings (ICR) of “a” of Atlantic Specialty Insurance Company (New York, NY) and its three U.S. reinsured affiliates, collectively referred to as OneBeacon Insurance Group (OneBeacon).

At the same time, A.M. Best has affirmed the ICRs of “bbb,” the issue rating on currently issued securities and indicative issue ratings on shelf registrations of OneBeacon’s publicly traded parent, OneBeacon Insurance Group, Ltd. (OneBeacon Ltd.) (Hamilton, Bermuda) [NYSE: OB] and OneBeacon U.S. Holdings, Inc. (OneBeacon U.S.), an intermediate holding company that issues securities in the United States.

Concurrently, A.M. Best has affirmed the ICR of “bbb” of the group’s ultimate parent, White Mountains Insurance Group , Ltd. (White Mountains) (Hamilton, Bermuda) [NYSE: WTM]. The outlook for all ratings is stable.

The ratings reflect the group’s solid risk-adjusted capitalization and profitable earnings driven by its generally positive underwriting results and steady investment earnings. The ratings also consider the financial flexibility of OneBeacon U.S. and OneBeacon Ltd.

These positive rating factors are partially offset by adverse development of loss reserves, including reserve actions recorded in 2014 related to the group’s on-going business, payment of significant shareholder dividends that has constrained growth in surplus, and a somewhat elevated level of equity investments, which – while well managed – has added volatility to the group’s earnings and balance sheet.

The affirmation of the ratings of OneBeacon Ltd., OneBeacon U.S. and White Mountains acknowledges the companies’ strong financial flexibility and solid operating performance generated through their operating subsidiaries. Financial leverage and interest coverage ratios are within A.M. Best’s guidelines for the ratings.

While the group’s ratings are stable, future positive rating actions may result if OneBeacon‘s underwriting and operating results outperform its peers for an extended period of time. Negative rating actions may result if the group’s underwriting and operating performance falls markedly short of A.M. Best’s expectation or if there were a material weakening of risk-adjusted capitalization.

The FSR of A (Excellent) and the ICRs of “a” have been affirmed for Atlantic Specialty Insurance Company and its following affiliates:

  • Homeland Insurance Company of New York
  • Homeland Insurance Company of Delaware
  • OBI National Insurance Company

The following issue rating has been affirmed:

OneBeacon U.S. Holdings, Inc.—

--“bbb” on $275 million 4.60% senior unsecured notes, due 2022

The following indicative ratings under the shelf registration have been affirmed:

OneBeacon U.S. Holdings, Inc. and OneBeacon Insurance Group, Ltd.—

--“bbb” on senior unsecured debt

--“bbb-” on subordinated debt

--“bb+” on preferred stock

OneBeacon U.S. Holdings Trust I, II, III—

--“bb+” on preferred stock

This press release relates to rating(s) that have been published on A.M. 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 visit A.M. Best’s Ratings & Criteria Center.

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