Reuters quoted Russian gas giant Gazprom as saying that it expected debt repayments to peak in 2018 and investments to peak between 2018 and 2020 as it boosted spending on major pipeline projects. Gazprom, which is involved in building three major gas pipeline projects to Europe, China and Turkey, frequently draws criticism from analysts who say it should rein in spending.

Gazprom expects its average annual investment until 2035 to be capped at RUB 1 trillion. Gazprom Group, which combines the gas business with the Russian firm's oil and power generation units, expects to spend RUB 1.28 trillion on investment this year.

Mr Andrey Kruglov, Gazprom Chief Financial Officer told investors in New York that the company would continue to be a big spender in the coming years, adding that its debt repayments would reach a high of more than USD 13 billion in 2018.

Mr Kruglov said that a negative net cash flow was fairly likely both this year and next.

The state-controlled Russian company is facing political resistance in Europe, particularly over Moscow's role in the Ukrainian crisis, but it still plans to boost its share of the European gas market.

Gazprom, whose gas business relies on pipelines, is also facing steeper competition from producers of liquefied natural gas (LNG), which can be shipped from sources around the world.