OneBeacon and Frontline Offer Motor Truck Cargo Program

Now available in nine states

CANTON, Mass., Aug. 16 -- OneBeacon Insurance Group today announced its alliance with Frontline Underwriters, Inc. to offer a new Motor Truck Cargo Program to transportation customers in nine states: Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee and Texas.

Said Don Keahon, OneBeacon's Vice President and Director of Inland Marine, "We are excited to partner with Frontline Underwriters and bring this program to the transportation marketplace. Frontline's preeminence in the motor truck segment nicely complements OneBeacon's focus on this specialty business. Through our combined expertise, enhanced coverages and personalized approach, we offer the transportation market in the southeast and Texas a total Motor Truck Cargo solution."

A full suite of motor truck cargo protection is available with the program, including standard inland marine coverages and program features such as expediting expenses, off-board and on-board electronic equipment and on-board supplies. As a leading insurance provider to the transportation segment, OneBeacon can also offer occupational accident coverage for owner operators as well as key risk management services such as travel assistance and a discount prescription drug program.

About Frontline Underwriters: Frontline Underwriters, Inc. is a privately owned wholesale insurance broker with specific expertise in all trucking lines of coverage: motor truck cargo, auto liability, auto physical damage, general liability and property. Through its relationships with OneBeacon Insurance and other "A" rated Admitted carriers that specialize in the transportation business, plus "A" rated surplus lines carriers with expertise in commercial auto, Frontline Underwriters offers one-stop shopping for the transportation-specific retail insurance agent.

About OneBeacon: OneBeacon Insurance Group, Ltd. is a Bermuda-domiciled holding company that is publicly traded on the New York Stock Exchange under the symbol "OB." OneBeacon Insurance Group's underwriting companies offer a range of specialty insurance products sold through select independent agents, regional and national brokers, and wholesalers. The company's businesses include OneBeacon Professional Insurance, International Marine Underwriters, Entertainment Brokers International Insurance Services, Specialty Accident and Health, OneBeacon Government Risks, OneBeacon Energy Group, A.W.G. Dewar (tuition refund), collector cars and boats written through Hagerty Insurance Agency, OneBeacon Technology Group, OneBeacon Financial Services, OneBeacon Specialty Property, Property and Inland Marine, and AutoOne.

As one of the oldest property and casualty insurers in the United States, OneBeacon traces its roots to 1831 and the Potomac Fire Insurance Company. Today, OneBeacon's specialty insurance businesses are national in scope.

Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995

This press release may contain "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements, other than statements of historical facts, included or referenced in this release which address activities, events or developments which we expect or anticipate will or may occur in the future are forward-looking statements. The words "will," "believe," "intend," "expect," "anticipate," "project," "estimate," "predict" and similar expressions are also intended to identify forward-looking statements. These forward-looking statements include, among others, statements with respect to OneBeacon's:

  --  change in book value per share or return on equity;
  --  business strategy;
  --  financial and operating targets or plans;
  --  incurred loss and loss adjustment expenses and the adequacy of its
      loss and loss adjustment expense reserves and related reinsurance;
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      share, dividends, market share or other financial forecasts;
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These statements are based on certain assumptions and analyses made by OneBeacon in light of its experience and perception of historical trends, current conditions and expected future developments, as well as other factors believed to be appropriate in the circumstances.

However, whether actual results and developments will conform to our expectations and predictions is subject to a number of risks and uncertainties that could cause actual results to differ materially from expectations, including:

  --  claims arising from catastrophic events, such as hurricanes,
      windstorms, earthquakes, floods, fires, explosions, terrorist attacks
      or severe winter weather;
  --  recorded loss and loss adjustment expense reserves subsequently
      proving to have been inadequate;
  --  the continued availability and cost of reinsurance coverage;
  --  the continued availability of capital and financing;
  --  general economic, market or business conditions;
  --  business opportunities (or lack thereof) that may be presented to it
      and pursued;
  --  competitive forces, including the conduct of other property and
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  --  changes in domestic or foreign laws or regulations, or their
      interpretation, applicable to OneBeacon, its competitors, its agents
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  --  an economic downturn or other economic conditions adversely affecting
      its financial position including stock market volatility;
  --  actions taken by ratings agencies from time to time, such as financial
      strength or credit ratings downgrades or placing ratings on negative
      watch;
  --  the risks that are described from time to time in OneBeacon's filings
      with the Securities and Exchange Commission, including but not limited
      to OneBeacon's Annual Report on the Form 10-K for the fiscal year
      ended December 31, 2009 filed February 26, 2010.

Consequently, all of the forward-looking statements made in this press release are qualified by these cautionary statements, and there can be no assurance that the actual results or developments anticipated by OneBeacon will be realized or, even if substantially realized, that they will have the expected consequences to, or effects on, OneBeacon or its business or operations. OneBeacon assumes no obligation to update publicly any such forward-looking statements, whether as a result of new information, future events or otherwise.