January 20 (SeeNews) - Croatian oil and gas group INA [ZSE:INA] said it signed on Thursday a deal with engineering company Koncar – Inzenjering za Energetiku I Transport, a unit of electrical equipment manufacturer Koncar Elektroindustrija [ZSE:KOEI], to build two solar power plants as a first step to creating a portfolio in the production of electricity from renewable sources.