Buenos Aires  - The Russian gas giant Gazprom does not rule out new interruptions in its supply of gas to Western Europe, due to the conflict with Ukraine over the hydrocarbon.

"We cannot guarantee 100 per cent that situations like that of 2005 and 2009 will not happen again," Gazprom number two Alexander Medvedev said Thursday, on the sidelines of the World Gas Conference in Buenos Aires.

He noted that Ukraine paid its Russian gas bill on time Wednesday and saw tjos as an encouraging sign, although he warned that Ukraine remains unreliable due to its internal political situation.

At the same time, Medvedev was confident that the Nord Stream Pipeline would manage in 2011, as planned, to deliver gas to Western Europe by a route under the Baltic, thus bypassing Ukraine.

"This is very important, because Europe urgently needs that gas," Medvedev said.

His remarks contradicted those by Vadim Chuprun, vice president of Ukraine's Naftogaz, who said Wednesday in Buenos Aires that Western Europe does not need the new Baltic pipeline or the southern route around Ukraine, the Nabucco Pipeline, at all. According to Chuprun, the Ukrainian transit network is enough in the face of falling demand.

Medvedev anticipated that the price of gas would rise again in the medium term.

"Still, Gazprom is not interested in exploding prices but in fair prices," he said.

Medvedev refused, however, to name a "fair" price, arguing that that would distort the markets.

He strongly advocated the formation of a world cartel of gas exporters, similar to the Organization of Petroleum-Exporting Countries (OPEC).

"When even cocoa producers have an agreement, why can we not have one?" he said.

Gazprom wants to continue to expand in China and South East Asia, which he described as strategic markets. Plans for the United States include aim of obtaining a market share of 4-5 per cent in five years, with an end goal of 10 per cent of the market.  dpa