Under the first contract, Gazprom’s wholly-owned subsidiary, Dutch-registered South Stream Transport, contracted Allseas to install the second subsea line under the TurkStream project to export Russian gas to Turkey and onwards to southern Europe.

Gazprom said the contract puts into effect the option that Allseas gave to South Stream Transport last year after signing an agreement for the first line of the project, running about 900 kilometres from Russia across the Black Sea.