What is Russia's end-game in gas row?

By Christian Lowe - Analysis

MOSCOW (Reuters) - Russian Prime Minister Vladimir Putin raised the stakes in his gas conflict with Ukraine by slashing supplies to Europe, a measure that has left some EU states struggling to heat homes in sub-zero temperatures.

Russian gas export monopoly Gazprom said it was forced to take that step because Ukraine -- locked in a dispute with Moscow over gas pricing -- was stealing gas being pumped across its territory for customers in Europe.

What was Putin seeking to achieve by reacting in this way? There is so far no consensus among diplomats and analysts about what Russia's end-game is. The following are the main theories:

RUSSIA HAS NO END-GAME

The Kremlin started out with the modest aim of persuading Ukraine to pay closer to market prices for its gas, but has now been out-manoeuvred by Kiev.

"Russia and Gazprom have walked into a trap," said Fyodr Lukyanov, editor of the journal Russia in Global Affairs.

He said Ukraine -- desperate not to pay more for its gas because of the fragile state of its economy -- seized the initiative from Moscow by endangering exports to Europe.

"They are calculating, and I think not without basis, that the longer this drags on the more the blame will be laid at Moscow's door," said Lukyanov.

He said Gazprom, under pressure from a Europe angry its supplies are being disrupted and fearful for its reputation as an energy supplier, will now be forced to cut the price it is demanding Ukraine pay for its gas.

"Ukraine wants to go back to the negotiations from a position of strength ... And it is working," he said.

KREMLIN PUSHING NEW PIPELINE PROJECTS

The disruption of gas flows to Europe has highlighted the fragility of transit routes -- playing into the Kremlin's hands as it tries to persuade Europe to back alternative pipelines.

Russia has been struggling to win European approval for the Nord Stream pipeline, which will ship gas under the Baltic Sea to Germany, bypassing potential troublesome transit states.

Nord Stream, a joint venture between Gazprom, Germany's BASF

and E.ON and Dutch firm Gasunie, has encountered resistance, on political and environmental grounds, from several European Union states.