The blocks offshore Mauritania range in water depths between 1,600m and 3,000m and cover a combined area of 27,200km².
Kosmos plans to acquire 2D and 3D seismic data and is expecting to start drilling in early 2014, in the initial exploration phase under each of the contracts.
Kosmos will be operator of the three blocks with a 90% share in each and national oil company, Societe Mauritanienne des Hydrocabures will hold a carried interest of 10%.
The contracts will take effect upon formal ratification by the Government of Mauritania.
Kosmos Energy chief executive officer Brian Maxted said that the exploration programme is focused on unlocking new petroleum systems by drilling multiple basin-opening wells on an annual basis.
"We have now captured approximately 24m gross acres of high-impact exploration potential, with additional new venture initiatives ongoing to selectively further our opportunity set," said Maxted.
"We look forward to initiating a seismic program over the blocks towards the end of this year or early next year."
