He joins from London listed Essar Energy (LON:ESSR), where he held the position of director of financial operations.
Tethys' chief financial officer, Bernard Murphy, said: "The appointment of Clive is a most welcome addition to our team and further strengthens it following Denise Lay's promotion to deputy chief financial officer.
"As vice president finance, Clive will be a key figure in managing and developing the finance function within our expanding company.
"His extensive accounting experience both within the oil and gas industry and elsewhere will be a welcome addition to the company's existing accounting resource."
Tethys is an oil and gas exploration and production company working in the Republics of Kazakhstan, Tajikistan and Uzbekistan.
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