OneBeacon Schedules Second Quarter 2009 Earnings Release and Webcast

HAMILTON, Bermuda, June 29 /PRNewswire-FirstCall/ -- OneBeacon Insurance
Group, Ltd. (NYSE: OB) will review its second quarter 2009 results via live
Webcast at 10:00 a.m. ET on Friday, July 31, 2009, following its earnings
release earlier that morning. The slide presentation that will be referenced
during the call, the press release and a financial supplement will be
available on the company's Web site: www.onebeacon.com. An audio playback of
the Webcast will be available on the site shortly following the call.

About OneBeacon: OneBeacon Insurance Group's underwriting companies offer a
range of specialty and segmented commercial and personal insurance products
sold through select independent agents, regional and national brokers, and
wholesalers. 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, while commercial lines business is produced in select
territories throughout the United States. Personal lines business is
concentrated in the Northeastern United States.

OneBeacon's U.S. headquarters is in Canton, Massachusetts. The company is
publicly traded on the New York Stock Exchange under the symbol "OB".

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;
-- projections of revenues, income (or loss), earnings (or loss) per
share,
dividends, market share or other financial forecasts;
-- expansion and growth of our business and operations; and
-- future capital expenditures.

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
casualty
insurers and agents;
-- changes in domestic or foreign laws or regulations, or their
interpretation, applicable to OneBeacon, its competitors, its agents
or
its customers;
-- 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, 2008 filed February 27, 2009.

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.

SOURCE OneBeacon Insurance Group, Ltd.

Investor Relations, Todd Mills, +1-781-332-7442, ir@onebeacon.com, or Media,
Carmen Duarte, +1-781-332-7268, cduarte@onebeacon.com, both of OneBeacon