The contracts for three Gorna Arda cascade projects, which will get underway the implementation of the overall project, were signed on Monday. Construction work on the three projects will begin in early June and is due for completion within a year. The total cost of the three projects will be BGN 19 million; the main investor will be the National Electric Company (NEC). An international tender for a strategic investor for the cascade will be invited in the very near future. Tractabel (Belgium), ENEL (Italy) a Canadian and a Norwegian companies are among those that have shown interest in the project.