Switzerland's Allseas Group S.A. has begun constructing the first stage of the Turkish Stream pipeline, Gazprom said.
Gazprom added Allseas' vessel Audacia had started laying pipes on the Russian shore of Black Sea.
In a statement, the company's Chief Executive Alexei Miller said the Turkish Stream project would be finished by the end of 2019.
"Today we started the practical part of realization of the Turkish Stream project – the offshore construction of the gas pipeline. The project is being implemented strictly according to the plan, and by the end of 2019 our Turkish and European consumers will have a new reliable route for the import of the Russian gas," Sputnik cited Miller as saying.
Moscow and Ankara signed an intergovernmental agreement in October 2016 envisioning the construction of two underwater legs of the Turkish Stream gas pipeline in the Black Sea. The annual capacity of each leg is estimated to reach 15.75 billion cubic meters of natural gas.
