Russia may freeze work on the Turkish Stream gas pipeline project for several years in retaliation against Ankara for the shooting down of a Russian air force jet, two sources at Russian gas giant Gazprom told Reuters.
The Kremlin has imposed trade sanctions on Turkey over the jet incident last week but so far the measures have not affected the Russian energy exports to Turkey that are the core of their economic relationship.
Freezing work on the pipeline - intended to pump Russian gas, via Turkey, into southeastern Europe while bypassing Ukraine - would have a more symbolic than practical effect because the project is already beset by delays and doubts over its viability.
Any freeze would also not affect another Russian project to boost gas exports to the north of Europe. Gazprom is going ahead with plans to expand the Nord Stream pipeline to Germany despite resistance from several ex-communist states in eastern Europe.
Gazprom sources said no decision had been taken inside the company about changes to the Turkish Stream schedule in response to the row with Ankara, but said they were awaiting instructions from President Vladimir Putin.
"We're expecting that the head of state, in all likelihood, could declare a freezing of Turkish Stream, or at least some kind of timeout should be announced," said one Gazprom source, who spoke on condition of anonymity.
A second source in Gazprom, who also did not want to be identified, said: "We are still hoping that Turkish Stream will be pushed back by a few years, rather than completely cancelled."
Russian Economy Minister Alexei Ulyukayev said last month Turkish Stream could be among the projects affected by sanctions against Turkey, but he did not specify how.