Tethys Petroleum Limited announced the appointment of Mattias Sjoborg to the Board of Directors of the Company. Mattias joined Plena Group in 2001 and has led teams through origination, due diligence, negotiation and the restructuring of medium to large emerging market enterprises. In 2011, Mattias bought out Plena Group in a management buy-out and has led its growth by continuing to assemble cross border transactions as well as government privatisations in predominantly emerging markets.