Gazprom Chief Executive Alexei Miller said in a statement issued Wednesday the decision will determine whether or not the utility will move ahead with plans for the project, which is envisioned to carry natural gas across the Black Sea to Europe.
Miller made the comments at a South Stream implementation meeting in Moscow with Marcel Kramer, chief executive of South Stream, and other pipeline officials.
Saying the brutally cold winter in Europe highlights the importance of new gas routes directly connecting European customers with Russian supplies, Miller clarified Gazprom's timetable for the South Stream project.
"We have brought South Stream to the actual construction stage," he said. "It is no exaggeration to say that Gazprom is busy with the project 24 hours a day.
"This abnormally cold winter, which caused a spike in demand for Russian gas in Europe, is another proof that South Stream has to be and will be built. Europe is in need for the new corridors delivering Russian gas with no transiters," Miller said.
While previously only saying a final investment decision on the project would be made sometime late in the year, Miller declared Wednesday officials had decided the call would be made in November.
Gazprom officials said they also talked about a decision made in December to speed up the pipeline plans.
The move as a brutal winter that has seen European natural gas supplies stretched to their limits and stored underground reserves tapped.
A construction launch could happen as early as December, in line with a request from Russian Prime Minister Vladimir Putin, with commercial deliveries to begin in 2015.
Partners in the pipeline's offshore section include Gazprom (50 percent) Italy's Eni (20 percent), along with Germany's Wintershall Holding and France's EDF at 15 percent each. Its capacity would be up to 63 billion cubic meters per year.
The pipeline would run under Turkish territorial waters of the Black Sea and include onshore sections in Bulgaria, Serbia, Hungary, Greece, Slovenia, Croatia and Austria -- all of which have set up national joint ventures.
Gazprom this month it has also begun discussions with Montenegro to join the South Stream project.
Earlier this month U.S. Secretary of State Hillary Clinton said in Bulgaria the United States supports efforts by that country to diversify its energy supplies -- interpreted to mean lessening its dependence on Russian gas and exploring shale gas reserves within its borders.
After Clinton's visit, Bulgarian Minister of Finance Simeon Djankov told national television Sofia is still fully committed to implementing the South Stream pipeline, the Brussels weekly New Europe reported.
"We remain in South Stream, it is a very promising project," he said.
Opponents, however, say the Bulgarian government's decision to align with Russia on the project is compromising its chances for energy independence.
A coalition of energy experts calling themselves the Movement for Energy Independence told reporters Tuesday the government has become fixated on the "uncertain" South Stream for reasons that economically benefit them while average Bulgarians' energy costs soar, the Sofia News Agency reported.
More promising energy projects, such as a gas grid interconnection between Turkey and Bulgaria, Danube River hydro-potential and shale gas exploration, have been neglected in favor of "kleptomanic schemes that benefit certain parties," the group said.