Bulgarian Economy and Energy Minister Delyan Dobrev and the head of Russian energy giant Gazprom Alexei Miller have concluded that the construction of the South Stream gas transit pipeline is progressing "as scheduled".

Dobrev and Miller met in Moscow Wednesday, with their talks focusing on the future of South Stream, in addition to the Russian natural gas supplies for Bulgaria, Gazprom said in a statement.

Bulgaria's Economy Minister and the CEO of Gazprom also noted the successful holding of a tender for picking a subcontractor for territorial planning, environmental impact assessment, and drafting the paperwork for the Bulgarian section of South Stream.

The South Stream pipeline is intended to transport up to 63 billion cubic meters of Russian natural gas to Central and Southern Europe annually, diversifying Russian gas routes away from transit countries such as Ukraine.

The pipe will go from Russia to Bulgaria via the Black Sea; in Bulgaria it will split in two – with the northern leg going through Serbia, Croatia, Hungary, and Slovenia to Austria and Northern Italy, and the southern leg going through Greece to Southern Italy.

The Black Sea underwater section of South Stream between Russia and Bulgaria will be 900 km long, and will be constructed at a maximum depth of 2 km.

In order to service the supplies for South Stream, Russia will expand its own gas transit network by building additional 2 446 km of pipelines with 10 compressor stations with a total capacity of 1473 MW, a project to be called "South Corridor" and to be completed in two stages by 2019.

The construction of the South Stream gas pipeline will begin in December 2012, and the first supplies for Europe are scheduled for December 2015.

The pipeline's core shareholders include Gazprom with 50%, Italy's Eni with 20% and Germany's Wintershall Holding and France's EDF with 15% each.

Gazprom has already established national joint ventures with companies from Austria, Bulgaria, Croatia, Slovenia, Greece, Hungary and Serbia to manage the onshore section of the South Stream pipeline.

Bulgaria recently committed itself to speeding up the construction of the Russian-sponsored pipeline on its territory, since on January 1, 2013, the EU is introducing new requirements for the access to energy networks.