UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 13F
FORM 13F COVER PAGE
INFORMATION REQUIRED OF INSTITUTIONAL INVESTMENT MANAGERS PURSUANT
TO SECTION 13(f) OF THE SECURITIES EXCHANGE ACT OF 1934 AND RULES THEREUNDER
Report for the Calendar Year or Quarter Ended: March 31, 2008.
CHECK HERE IF AMENDMENT |_|; AMENDMENT NUMBER:
This Amendment (Check only one.): |_| is a restatement.
|_| adds new holdings entries.
INSTITUTIONAL INVESTMENT MANAGER FILING THIS REPORT:
Name: OneBeacon Insurance Group, Ltd.
Address: 601 Carlson Parkway
Minnetonka, Minnesota 55305
U.S.A.
Form 13F File Number: 028-12951
The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.
PERSON SIGNING THIS REPORT ON BEHALF OF REPORTING MANAGER:
Name: Ann Marie Andrews
Title: Chief Accounting Officer
Phone: (781) 332-6000
SIGNATURE, PLACE, AND DATE OF SIGNING:
/s/ Ann Marie Andrews Canton, Massachusetts May 13, 2008
--------------------- --------------------- ------------
[Signature] [City, State] [Date]
REPORT TYPE (CHECK ONLY ONE.):
|_| 13F HOLDINGS REPORT. (Check here if all holdings of this reporting
manager are reported in this report.)
|_| 13F NOTICE. (Check here if no holdings reported are in this report, and all
holdings are reported by other reporting manager(s).)
|X| 13F COMBINATION REPORT. (Check here if a portion of the holdings for this
reporting manager are reported in this report and a portion are reported by
other reporting manager(s).)
List of Other Managers Reporting for this Manager
[If there are no entries in this list, omit this section.]
No. Form 13F File Number Name
1. 028-04685 Prospector Partners, LLC
FORM 13F SUMMARY PAGE
Report Summary:
Number of other included managers: 1
Form 13F Information Table Entry Total: 28
Form 13F Information Table Entry Value Total: 32,678
(thousands)
List of other included managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.
No. Form 13F File number: Form 13F File Number: Name:
1 28 - N/A Copley Square Capital Management, LLC
VOTING
INVESTMENT DISCRETION AUTHORITY SHARES
----------------------------- ------------------
NAME OF ISSUER CLASS CUSIP FAIR MV SHARES SOLE SHARED AS SHARED-OTHER SOLE SHARED NONE
------------------------ --------- --------- --------- ------ ---- --------- ------------ ---- ------ ----
American INTL Group Inc Com 026874107 865,000 20,000 x x
Automatic Data Proc Com 053015103 847,800 20,000 x x
Bank New York Mellon Com 064058100 1,460,550 35,000 x x
Cardinal Health Inc Ohio Com 14149Y108 262,550 5,000 x x
Colgate Palmolive Com 194162103 1,947,750 25,000 x x
CVS Caremark Corp Com 126650100 2,430,600 60,000 x x
Embraer Empresa Bras ADR ADR 29081M102 395,100 10,000 x x
Ethan Allen Interiors Com 297602104 454,880 16,000 x x
Goldman Sachs Group Inc. Com 38141G104 826,950 5,000 x x
Hartford Finl Svcs Group Com 416515104 757,700 10,000 x x
Honda Motor ADR New AMERN SHS 438128308 1,152,400 40,000 x x
Honeywell Intl Inc Del Com 438516106 2,821,000 50,000 x x
Illinois Tool Works Inc Com 452308109 1,929,200 40,000 x x
Kraft Foods Inc VA CL A CL A 50075N104 775,250 25,000 x x
L-3 Communications Hldgs Com 502424104 2,733,500 25,000 x x
Marathon Oil Corp Com 565849106 1,824,000 40,000 x x
Nucor Corporation Com 670346105 1,354,800 20,000 x x
Patriot Coal Corp Com 70336T104 23,485 500 x x
Peabody Energy Corp Com Com 704549104 765,000 15,000 x x
Plum Creek Timber Co Inc Com 729251108 1,017,500 25,000 x x
Safeway Inc New Com 786514208 587,000 20,000 x x
Staples Inc Com 855030102 442,200 20,000 x x
TJX Cos Inc New Com 872540109 1,984,200 60,000 x x
Toronto Dominion Bank Com 891160509 613,500 10,000 x x
Wellpoint Inc Com 94973V107 1,103,250 25,000 x x
Weyerhaeuser Co Com 962166104 650,400 10,000 x x
Yum Brands Inc Com 988498101 1,860,500 50,000 x x
3M Company Com 88579Y101 791,500 10,000 x x