EXHIBIT 4.1 NUMBER SHARES COMMON SHARES COMMON SHARES THIS CERTIFICATE IS TRANSFERABLE IN CUSIP G7127P 10 0 NEW YORK, NY AND RIDGEFIELD PARK, N.J. SEE REVERSE FOR CERTAIN DEFINITIONS PLATINUM UNDERWRITERS HOLDINGS, LTD. ORGANIZED UNDER THE LAWS OF BERMUDA This Certifies that is the registered holder of FULLY PAID AND NON-ASSESSABLE SHARES OF THE PER VALUE OF $0.01 EACH OF THE CAPITAL OF COMMON SHARE CERTIFICATE DATED /s/ Jerome T. Fadden /s/ Steven H. Newman President Chairman COUNTERSIGNED AND REGISTERED: MELLON INVESTOR SERVICES LLC TRANSFER AGENT AND REGISTRAR, BY AUTHORIZED SIGNATURE PLATINUM UNDERWRITERS HOLDINGS, LTD. The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN COM - as tenants in common TEN ENT - as tenants by the entireties JT TEN - as joint tenants with right of survivorship and not as tenants in common UNIF GIFT MIN ACT- Custodian ---------------------------------- (Cust) (Minor) under Uniform Gifts to Minors Act --------------------------------- (State) Additional abbreviations may also be used though not in the above list. FOR VALUE RECEIVED, __________ HEREBY SELL, ASSIGN AND TRANSFER UNTO PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE - --------------------------------------- | | - --------------------------------------- ________________________________________________________________________________ (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) ________________________________________________________________________________ ________________________________________________________________________________ _______________________________________________________________________ SHARES REPRESENTED BY THE WITHIN CERTIFICATE, AND DO HEREBY IRREVOCABLY CONSTITUTE AND APPOINT ______________________________________________ ATTORNEY TO TRANSFER THE SAID SHARES ON THE BOOKS OF THE WITHIN NAMED COMPANY WITH FULL POWER OF SUBSTITUTION IN THE PREMISES DATED _______________________ ___________________________________________________________ NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER. Signature (s) Guaranteed: _____________________________________________________ THE SIGNATURE(S) MUST BE SIGNED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM). PURSUANT TO S.E.C. RULE l7A-l5.