Sterling Energy has agreed to acquire a 40.5% interest in the production sharing contract (PSC) for the Block C-3 prospect in Mauritania from Tullow Mauritania.
Tullow Mauritania operates the PSC with a 90% stake. Société Mauritanienne des Hydrocarbures et du Patrimoine Minier owns the remaining 10% interest.
Sterling will pay $2.5m for the 40.5% interest in the PSC, which will see Tullow retain a 49.5% stake.
Block C-3 is in its initial phase of exploration and is scheduled to expire on 30 June 2016. The block covers an area of approximately 9,800km².
Tullow has already acquired about 1,600km of 2D seismic data, which is due to be processed in 2015.
Competion of the acquisition and processing of this data represents the minimum work obligation during Phase 1 of the exploration period.
Sterling Energy chairman Alastair Beardsall said: "We are very pleased to be joining Tullow in Block C3 in Mauritania, which we consider to be highly prospective.
"Block C-3 has an active work programme and we look forward to working with Tullow in the exploration of this largely unexplored block."
Sterling Energy is focused principally on high potential exploration opportunities in Africa. The company owns a 50% interest in Ntem, a deepwater offshore exploration block in Cameroon.