Blue Stream, with a total length of 1,213 kilometers (754 miles), carries gas directly from Russia to Turkey across the Black Sea seabed.
"Gazprom has increased its gas deliveries to Turkey through the Blue Stream pipeline to 40 million cubic meters per day," Gazprom's press service said.
The move is a follow-up to an increase in deliveries from 30 million to 38 million cubic meters last December following a decline in Iranian gas supplies to Turkey.
Accordingly, Russia supplied Turkey with some 90 million cubic meters in excess of the contracted volume from December 25 through January 13.
Last Monday, Turkey's NTV television station quoted the country's Minister of Energy and Natural Resources Hilmi Guler as saying that Iran had suspended supplies of natural gas to Turkey due to a cold weather front which had brought a sharp fall in temperatures, as well as rain and snow, to the region.
Under a contract signed in 1996, Iran is obliged to ensure daily supplies of 28 million cubic meters of natural gas to Turkey via a 2,500-km (8,200 feet) pipeline connecting the two countries.
Iran has in the past halted natural gas deliveries to Turkey several times during the winter months, citing increased domestic demand.
Turkey has never built domestic fuel storage facilities and always compensated for a shortage of exports from Iran with additional supplies from Russia and other countries.
Turkey has also stopped the transit of Azeri gas to Greece pending the resumption of the Iranian supplies.
