Russian President Vladimir Putin is due to open the World Conference on Climate Change, which will convene some 1,200 experts from 43 countries to present 500 scientific papers.

But in the days before the event, Russian and foreign experts said that Moscow would make its decision on the Kyoto treaty on economic and political criteria, rather than purely ecological considerations.

Deputy Prime Minister Alexei Gordeyev told reporters on Thursday that Russia has "no schedule" for ratifying the treaty.

And on Friday an official in the presidential administration said Russia would only ratify Kyoto if it received firm guarantees on investment and on the sale of emission rights.

"We want a legislative and financial mechanism for the sale of quotas to be drawn up, and we want specific joint projects and guarantees on the purchase of Russian emission quotas for a precise sum," the official said.

European officials have already ruled out such a prospect as unrealistic.

Last week a member of the entourage of European Commissioner for the Environment Margot Wallstroem noted that Kyoto signatories "will not know until a year before the deadline" what quantities they will be able to buy on the market.

The Kyoto protocol, signed in 1997, provides for a worldwide reduction in the emission of greenhouse gases held responsible for global warming, notably carbon dioxide.

To come into force it requires the ratification of countries representing at least 55 percent of the global total of carbon dioxide emissions. With the United States refusing to ratify the treaty, Russia's signature is needed to pass the threshold.

Experts agree that the treaty is beneficial to Russia since it allows countries to buy or sell pollution quotas and Russia, following the post-Soviet collapse of much its antiquated industry, would have quotas for sale.

Even by 2010 its CO2 emissions will be between 11 and 25 percent below their benchmark 1990 levels, according to the last Russian report to the United Nations.

Russia can also benefit from the Kyoto treaty by modernising its energy sector under a clause that allows an industrialised country to avoid a forced reduction in its own emissions in exchange for a "clean" investment abroad, a leading pro-Kyoto deputy, Alexander Kosarikov said.

The Russian authorities have appeared indecisive on the issue over the past year and a half amid internal rivalries and a background of upcoming presidential and parliamentary elections, said ecologist Alexei Kokorin.

In September 2002 Putin and Prime Minister Mikhail Kasyanov hinted strongly at a Johannesburg summit that Russia would eventually ratify the pact. But since then, Russian officials have issued a series of contradictory statements.

Faced with these divisions, Putin's opening address Monday may seek to straddle the fence, offering hope to European countries that have been pressing him to sign up but linking the move to Russian entry into the World Trade Organisation.

SPACE.WIRE