But disputes over economic policy and cross-border mergers threaten to block any kind of agreement.
French President Jacques Chirac defended his government's attempt to block the takeover of leading French energy giants by an Italian company.
Spain, Poland, and Italy have also tried to block recent cross-border mergers in other sectors.
Austrian Chancellor Wolfgang Schussel, whose country currently heads the EU's rotating presidency, appealed to his fellow leaders to move away from economic protectionism.
The summit is also expected to discuss proposals for the further enlargement of the EU to Turkey and the Balkans, and moves to revive debate about the currently moribund EU constitution.
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- Ukraine consumes 70 billion cubic meters (bcm) of gas per year. It produces 20 bcm of its own gas, has a signed contract to import 40 bcm from Turkmenistan, and in 2005 was getting 29 bcm from Russia as payment for transit of Russian gas.
- Ukraine sells some 7 bcm of gas a year to the West and places some in underground storage facilities. These facilities can hold 34.5 bcm.
- Ukraine is the sixth-largest consumer of gas in the world and uses more gas than Poland, the Czech Republic, Hungary, and Slovakia combined.
- Russia has proven gas reserves of 47 trillion cubic meters (tcm) -- the largest in the world ahead of Iran and Qatar.
- Russia sells approximately 160 bcm to Europe each year. By 2015, Europe is expected to import 300 bcm, or 40 percent of its projected needs from Russia.
- Russia's Gazprom is the world's largest gas company. It is the only company allowed by Russian law to export gas outside the borders of the CIS. It also owns the gas-transportation system and most of the gas fields in Russia.
- The Russian state is Gazprom's majority shareholder , with a 51 percent share. The company's ownership rights changed as of the beginning of 2006, with Gazprom stock being sold on the open market. The Russian state, however, will continue to hold the majority stake.