With this acquisition, the company has increased its shareholding in Seven Stars to 85% from 51%.
Tethys CEO David Robson said the move will allow Tethys a greater share in a very prospective, yet underexplored area.
Seven Stars is the owner of the rights to the Bokhtar production sharing contract in Tajikistan.
Tethys is focused on oil and gas exploration and production activities in Central Asia, with activities currently in Kazakhstan, Tajikistan and Uzbekistan.
