Russia in return pledged to move ahead with ratification of the Kyoto climate change treaty as Brussels offered a major concession by dropping demands for Russia to hike its low domestic energy prices to world levels.

EU Trade Commissioner Pascal Lamy and Russian Trade Minister German Gref signed a protocol concluding six years of thorny negotiations on Russian membership of the WTO in the presence of Russian President Vladimir Putin and the EU leadership.

The deal crowned a Russia-EU summit, the first since the European Union expanded its membership from 15 nations to 25 on May 1, with former Warsaw Pact countries that still have strong economic links to Russia entering the bloc.

"The fact that the European Union has made concessions in our WTO negotiations cannot but have a positive effect on Moscow's attitude towards ratification of the Kyoto protocol," Putin said.

"We will accelerate our efforts to ratify this protocol," Putin added.

However, he cautioned that Russia still had "several concerns" about its obligations under the treaty and declined to set a firm date for ratification, saying this was a matter for parliament.

The European Union has repeatedly called on Russia to ratify Kyoto -- aimed at reducing the emissions which cause global warming of the atmosphere -- and linked the issue to the Russian WTO accession.

Ahead of the summit, Russia took a tough stance on the Kyoto pact, warning that it would not even be discussed. Its participation is needed to rescue the pact after the United States walked away from the deal in 2001.

European Commission President Romano Prodi hailed the agreement with Russia, for whom the EU is its main commercial partner now accounting for more than 50 percent of trade.

"Today, the EU and Russia cement further their trade and economic relations. This deal brings Russia a step closer to the international trade family, the World Trade Organization, where it belongs," he said.

"This protocol is a compromise, both of us have moved," Prodi added.

Russia, the largest nation to be left out of the 147-member world trade governing body, must still strike agreements with the United States and China before joining the WTO.

Putin sounded optimistic, saying that "this agreement will have a positive effect on our negotiations with the United States and China."

Negotiations had come down in recent months to the European Union's insistence that Russia end its practice of setting artificially low domestic energy tariffs, which Brussels said gave unfair trade benefits to Russian producers.

The European Commission said in a statement that Moscow had pledged to increase domestic gas prices for industrial users from 27 to 28 dollars per 1,000 cubic metres to 49 to 57 dollars by 2010.

However, Western European countries currently pay 110 dollars per 1,000 cubic metres for supplies of Russian gas.

Moscow offered to provide access for independent firms to its state-run gas and oil pipeline networks but refused to break up the export monopoly of state-dominated gas behemoth Gazprom, the world's biggest natural gas producer.

Russia was also asked to provide commitments to open up its banking and insurance markets to European companies.

Irish Prime Minister Bertie Ahern, whose nation holds the rotating presidency of the European Union, expressed optimism at the summit that Brussels would build a closer partnership with Moscow.

"Three weeks ago we welcomed 10 new states (into the European Union). Enlargement will bring the European Union and Russia closer together. It will bring us more opportunities for cooperation," he said.

SPACE.WIRE