Turkish contractor IC Içtaş got back the Akkuyu nuclear power plant construction contract after reaching an agreement with Russia, sources said Friday.

Akkuyu is the world’s first nuclear power plant project implemented through a build-own-operate model. Under the long-term contract, Rosatom has agreed to provide the power plant’s design, construction, maintenance, operation and decommissioning.

Last month, Russian state nuclear energy company Rosatom terminated a contract with IC Içtaş, its Turkish partner, over alleged "violations" in the contract.

The firm holds a 99.2% stake in the project that is estimated to cost around $20 billion (TL 357.98 billion), marking the biggest investment in Turkey’s history implemented at a single site.

IC Içtaş is an experienced Turkish contractor, having delivered a number of infrastructure and energy projects both at home and abroad. The company undertook the construction of the third bridge on the Bosporus, Yavuz Sultan Selim, and the Northern Marmara Highway. The company also constructed infrastructure projects in Russia and built the St. Petersburg Western High Speed Diameter (WHSD) project. It has important public-private partnerships (PPP) in Russia and has strategic importance in St. Petersburg city's transport system.