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CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-68438) of OneBeacon Insurance of our report dated June 16, 2004 relating to the financial statements of the OneBeacon Insurance Savings Plan, which appears in this Form 11-K.
/s/ PricewaterhouseCoopers LLP
Boston, Massachusetts
June 28, 2004