SOFIA (Bulgaria), June 16 (SeeNews) – The International Court of Arbitration in Paris has ruled that Bulgaria's heavily indebted state-owned National Electricity Company, NEK, must pay 550 million euro ($619 million) to Russia's Atomstroyexport as compensation for the country's decision to abandon a nuclear power plant construction project, prime minister Boyko Borissov said on Thursday as quoted by local media.