These excerpts taken from the BP 6-K filed May 22, 2008.
Form of transfer of certificated shares
44 All transfers of shares, other than shares represented by Share Warrants, or uncertificated shares, may be effected by transfer in writing in any usual or common form or in any other form acceptable to the Directors and may be under hand only. The instrument of transfer (if any) shall be signed by or on behalf of the transferor and (except in the case of fully paid shares) by or on behalf of the transferee. The transferor shall remain the holder of the shares concerned until the name of the transferee is entered in the Register of Members in respect thereof.