MOSCOW, September 14 (RIA Novosti) - France's GDF Suez will by the end of October become a shareholder in the company building the Nord Stream gas pipeline under the Baltic Sea, Gazrpom's deputy CEO said on Monday.

The $6 billion-euro Nord Stream pipeline between Russia and Germany is designed to eventually pump 55 billion cu m of Siberian gas per year to Western Europe, bypassing traditional transit nations.

"All decisions should be agreed upon, [the company's accession] can be expected in September-October," Alexander Medvedev said.

The Gazprom official announced in June that German partners of the Russian energy giant had agreed to cede part of their stake in Nord Stream AG to GDF Suez, so that the French company would be on a level with the Dutch minor partner Gasunie, which owns 9%.

Germany's Wintershall Holding and E.ON Ruhrgas currently each control 20%, while the Russian gas monopoly has a 51% stake.

Talks to admit GDF Suez were started in April.

The Nord Stream project has triggered environmental concerns among Baltic Sea states and fears in traditional transit countries that they will lose leverage when buying Russian gas, on which they are heavily reliant.