These excerpts taken from the BP 6-K filed May 22, 2008.
Chairman and Deputy Chairman
112 (A) The Directors may elect from their number a Chairman and a Deputy Chairman (or two or more Deputy Chairmen) and determine the period for which each is to hold office. If no Chairman or Deputy Chairman shall have been appointed or if at any meeting of the Directors no Chairman or Deputy Chairman shall be present within five minutes after the time appointed for holding the meeting, the Directors present may choose one of their number to be chairman of the meeting.
(B) If at any time there is more than one Deputy Chairman the right in the absence of the Chairman to preside at a meeting of the Directors or of the Company shall be determined as between the Deputy Chairmen present (if more than one) by seniority in length of appointment as Deputy Chairman or otherwise as resolved by the Directors.
112 (A) The