Summary

• Mauritania: the reserves stated are for the Chinguetti field only and are based on Sterling’s own assessment of reserves, as at 31 December 2011. Sterling’s interest in the Chinguetti field is through its Funding Agreement and Royalty Agreements; Sterling does not have a direct equity participation in the Chinguetti field.
• Sterling has not booked reserves in Mauritania relating to other discoveries, on the basis that there are no approved development plans for these discoveries.
• In accordance with the guidelines of the AIM Market of the London Stock Exchange, Dr Philip Frank, Ph.D. Geology (1977), Exploration Director of Sterling Energy Plc, who has been involved in the oil industry for over 30 years, is the qualified person that has reviewed the assessment of reserves set out above.
• Definitions: proven reserves have a 90% level of confidence to the stated quantities will be equalled or exceeded. Probable reserves have a 50% level of confidence that the stated quantity will be equalled or exceeded. Oil includes condensates.