The Romanian government adopted the support agreement that establishes the means for the government to secure financing for the pipeline planned from Azerbaijan.
The BP-led consortium managing the Shah Deniz II natural gas field in the Azeri waters of the Caspian Sea is expected by June to choose between Nabucco West and the Trans-Adriatic Pipeline as its conduit to Europe.
"This is another important step forward, illustrating the advanced stage of development of the Nabucco pipeline, a project which will ensure the diversification and security of energy supplies in Europe," Reinhard Mitschek, managing director Nabucco Gas Pipeline International GmbH, said in a statement.
The 820-mile, 48-inch Nabucco West pipeline is part of the Southern Corridor, a planned network of natural gas pipelines meant to break the Russian grip on the regional energy sector.
Russian energy company Gazprom is sending gas through the Nord Stream pipeline in the Baltic Sea as part of an export diversification strategy. Its planned South Stream pipeline could run through Southern Europe.