TIMELINE: Gas crises between Russia and Ukraine

(Reuters) - Ukraine removed conditions on Monday that threatened a gas deal to resume Russian supplies, to resolve a row that has plunged much of Europe into an energy crisis.

Here are some details about recent gas crises between Russia and Ukraine:

* WINTER 2005-2006:

-- Russia and Ukraine clashed over prices for the first time following the 2004 pro-Western "Orange Revolution" which swept President Viktor Yushchenko to power. Yushchenko has tried to withdraw Ukraine from Russia's sphere of influence.

-- A dispute over gas prices -- Ukraine then paid just $50 per 1,000 cubic meters, Gazprom wanted to charge $230 -- was complicated by accusations of corruption in the energy sector from Prime Minister Yulia Tymoshenko.

-- Gazprom cut off supplies on January 1 2006, but turned them on again a day later. European consumers complained their supplies had been hit. Gazprom accused Ukraine of stealing gas from export pipelines, but Kiev denied this.

-- Ukraine agreed to a price of $95 per tcm and the introduction of intermediary RosUkrEnergo, which soon became a source of conflict over future gas agreements.

* FEBRUARY 2007:

-- Ukraine's parliament passed a law banning the privatization, sale or lease of gas pipelines, after Russia suggested creating a joint venture to run the system.

* FEBRUARY 2008:

-- Gazprom said Ukraine had accumulated more than $1.5 billion in debts for supplies in 2007, when it was paying $130 per tcm. After weeks of talks and contradictory statements from both sides, it halved supplies briefly at the beginning of March.

-- Supplies were resumed after Naftogaz agreed to pay back the debt but analysts predicted tough talks over next year's supply deal and the question of intermediary RosUkrEnergo, which Tymoshenko wants abolished as the intermediary supplier.

-- In October, Tymoshenko and Prime Minister Vladimir Putin signed a memorandum that stipulated Ukraine would pay a market price within three years after gradual rises and that supply intermediaries like RosUkrEnergo would be scrapped.

* WINTER 2008-2009

-- Gazprom cut off all supplies for Ukraine's use on January 1, after weeks of negotiations on outstanding debts and prices for 2009. Gazprom proposed to raise the price to $250 from $179.5. Ukraine said it was prepared to pay $201 and wanted to raise gas transit fees. Gazprom then raised the price again to $458.

-- Russia accused Ukraine of corruption and stealing gas meant for Europe, and on January 7, Russian Prime Minister Vladimir Putin ordered a halt in gas transit via Ukraine as well, saying it was pointless pumping the gas if it was being stolen by Ukraine. Kiev said Russia's actions amounted to blackmail to extract an unjustifiably high price for the gas it sells to Ukraine.

-- Both sides said they would guarantee transit of Russian gas through Ukraine to Europe. Europe receives 80 percent of its Russian gas, a fifth of its total needs, from pipelines that run via Ukraine. Supplies to 18 countries in Europe were disrupted after Gazprom cut off supplies.

-- Ukraine signed a deal on Sunday allowing EU, Ukrainian and Russian observers to monitor gas flows across Ukrainian territory. Later in the day a deal to restore gas supplies to Europe via Ukraine had appeared on the verge of collapse after Moscow rejected handwritten additions by Kiev as a 'mockery of common sense'. Ukraine removed the additions on Monday opening the way for a resolution of the row.

-- Experts have said it may take 36 hours from the time gas starts flowing for capacity to build up in pipelines so that supplies reach consumers in Europe.