* Bulgaria say deliveries have dropped
* Poland, Hungary and Romania also affected
* Ukraine accuses Russia of "energy blackmail"
* EU calls for special talks, says deals must be honoured
By Guy Faulconbridge and Sabina Zawadzki
KIEV, Jan 3 (Reuters) - Russian gas flows to Bulgaria dropped on Saturday in a fresh sign that Moscow's decision to cut off its neighbour Ukraine in a row over pricing was disrupting supplies to some European Union members.
Bulgaria's Bulgargaz operator joined energy firms in Poland, Romania and Hungary in saying they had noted falls in supply, though the main pipeline through the Czech Republic to Germany -- Europe's biggest economy -- was working normally.
Russia has accused Ukraine of stealing gas in transit to Europe but in Kiev, state energy firm Naftogaz hit back by saying Russian gas export monopoly Gazprom <GAZP.MM> had itself reduced supplies to Europe and was using "energy blackmail."
Gazprom halted supplies to Ukraine on New Year's Day, saying Ukraine had failed to pay its gas bill and talks on 2009 gas prices had broken down.
Three years after a similar dispute briefly disrupted supplies, European fears of gas flows dropping off in the dead of winter were once again becoming a reality.
The European Union, which gets a fifth of its gas from pipelines that cross Ukraine, said it would call a crisis meeting of envoys in Brussels on Monday and demanded that transit and supply contracts be honoured.
"Energy relations between the EU and its neighbours should be based on reliability and predictability," the Czech presidency of the 27-nation bloc said in a statement on Friday.
The disruptions are likely to undermine Russia's attempts to present itself as a stable energy supplier and add to concern that Moscow is trying to bully its neighbours just five months after the war with Georgia.
Ukrainian President Viktor Yushchenko has angered the Kremlin by trying to join the NATO military alliance.
Europe, where temperatures fell below freezing overnight, has enough gas stockpiled to manage without Russian supplies for several days but could face difficulties should problems last for weeks, analysts said.
EUROPEAN SUPPLIES
Bulgargaz CEO Dimitar Gogov said supply levels have not fallen below a critical level but further reductions could force the company to introduce restrictions for customers.
"The pipeline pressure has dropped and we are getting smaller deliveries as of Saturday morning," Bulgargaz's chief executive Dimitar Gogov told Reuters.
Ukraine's Naftogaz issued a statement saying Russia was responsible for the fall in supplies to Europe and it urged Moscow to restart talks soon.
"The company thinks that Gazprom's position breaches international practices of holding negotiations ... and amounts to energy blackmail," the company said.
In an indication of how seriously Moscow and Kiev view the crisis, both sides had delegations touring European capitals to explain their positions.
Alexander Medvedev, head of Gazprom's export arm, was in the Czech Republic, holder of the EU's rotating presidency, for talks with officials.
Russia's 2006 dispute with Ukraine prompted calls for the EU to reduce its reliance on Russian gas but Gazprom forecasts that the bloc will rely on Russia for as much as one-third of its gas by 2015, up from about a quarter now.
Alexei Miller, CEO of Gazprom, said on Thursday he wanted Ukraine to pay $418 per 1,000 cubic metres (tcm) of gas, compared with the $179.50 Kiev paid in 2008.
Talks between Gazprom and Ukraine's state-run gas company, Naftogaz, have not resumed since failing late on New Year's Eve and the two sides remain far apart.
Ukraine says the most it can afford to pay is $235 but only if Gazprom pays it more for gas transit. Gazprom says it already has a gas transit deal to 2010 and does not need to rework it.
Ukraine, facing a deep recession, says it can ill afford to pay higher prices for its gas.
Ukrainians on the street in Kiev seemed to blame their own politicians for failing to get a deal with Russia.
"This is just bandits sitting in the Kremlin arguing, deciding, talking to bandits sitting in Grushevska street," Oleg Karlichyk a plumber in his mid-30s going on his way to work, said referring to the seats of power in Moscow and Kiev.