On Ruhrgas, Gazprom Export, GDF Suez, Qatar Petroleum, Royal Dutch Shell and Statoil - would like to see coal's share of the energy mix fall from 24% currently to between 4% and 9% by 2030.

BBC: Coal-to-gas power shift 'to cut energy costs'

Its cost will be borne by Russian taxpayers rather than by Gazprom, as the discount in gas prices to Ukraine will be provided by a cut in export duty paid by Gazprom to the Russian state.

ECONOMIST: Ukraine and Russia: A normal day's debate in Kiev | The

Sakhalin Energy has the dubious distinction of being the only big energy project in Russia not to involve a Russian firm, and the two big Sakhalin projects are the only exceptions to Gazprom's gas-export monopoly.

ECONOMIST: Russian energy

To entice Ukraine to sign contracts, Gazprom will allow it to re-export any gas it does not consume domestically.

ECONOMIST: Ukraine and Russia: A normal day's debate in Kiev | The

But these companies lack the best incentive to raise their production, or develop new fields in inaccessible places: the right to export gas beyond the former Soviet Union (which is a Gazprom monopoly).

ECONOMIST: Russian gas and Europe