February 20 (SeeNews) - The energy ministry of Bosnia's Serb Republic said it signed a 50-year concession contract worth 127.7 million marka ($69.8 million/65.3 million euro) with hydro power producer Hidroelektrane na Trebisnjici (HET) [BANJ:HETR-R-A] for the construction of a 33.5 MW hydro power plant.