Russian gas giant Gazprom announced yesterday it had decided to file a suit against Ukraine's national gas company Naftogaz to ensure transit of Russian gas through Ukrainian territory to Europe.

Chief executive Alexei Miller said the company would ask the Stockholm arbitration court to order Naftogaz to refrain from 'any actions aimed at reducing Russian transit gas to Europe.'

Meanwhile, the deputy head Gazprom, Alexander Medvedev, accused Ukraine of stealing 35 million cubic metres of Russian gas per day intended for Europe, saying Kiev would have to pay for it.

Medvedev was speaking after arriving in Prague for talks with the EU on his country's gas dispute with Ukraine, as several EU countries reported shortages of gas from Russia.

The Czech Republic, which currently holds the EU presidency, has called for a resumption of disrupted supplies.