Russian state-owned energy giant Gazprom has reportedly cancelled a 10.25 percent discount on natural gas for at least six private Turkish companies.

According to Stratfor, the companies, Enerco Enerji, Bosphorus Gaz, Avrasya Gaz, Shell, Bati Hatti, and Kibar Enerji, each import at least 10 billion cubic meters of natural gas from Russia annually in line with an agreement signed in 2012.

The discount had been in effect since Jan 1, 2015.

Unnamed officials said that representatives of Gazprom and the firms met in the recent weeks and decided on lifting the discount.

Overall, Turkey imports 60 per cent of its natural gas — 28-30 billion cubic meters annually — and 35 percent of its oil from Russia.