External audit
The external auditors started the annual cycle with their audit strategy which identified key risks to be monitored during the year – including the provisions and contingencies related to the Gulf of Mexico oil spill, the impact of the estimation of the quantity of oil and gas reserves and resources on impairment testing, depreciation, depletion and amortization
and decommissioning provisions, unauthorized trading activity and BP’s ability to maintain significant influence over Rosneft and consequently our ability to recognize our share of Rosneft’s income, production and reserves. The committee received updates during the year on the audit process, including how the auditors had challenged the group’s assumptions on these issues.