The Nord Stream gas pipeline from Russia to Europe will be launched on November 8, Russia's energy monopoly Gazprom said on Monday.
The pipeline will deliver Russian gas via the Baltic Sea to Germany, bypassing key transit countries Ukraine and Belarus.
There have been fears that the pipeline may cause harm to the Baltic - reported to be one of world's most polluted seas - but Prime Minister Vladimir Putin insisted last year the project was safe.
Speaking during a meeting with Putin outside Moscow, Gazprom head Alexei Miller said construction of the first leg of Nord Stream had been completed.
"Today I can name the exact date when the pipeline will start operating. It's November 8, 2011," Miller told the Russian premier.
Russia provides up to 30 percent of the gas consumed in Europe.