Russia and Bulgaria signed on Friday a road map for the technical and economic assessment of Bulgaria's section of the South Stream gas pipeline, an advisor to the Russian Energy Ministry said.

The document was signed in the presence of Bulgarian Prime Minister Boyko Borisov.

The South Stream pipeline will transport Russian gas to western Europe bypassing Ukraine. The offshore part, operated by Russia's Gazprom and Italy's ENI, will run for 900 km (559 miles) from Russia's mainland under the Black Sea to the Bulgarian coast and carry up to 63 billion cubic meters of gas a year.

The launch of the gas pipeline is scheduled for December 2015.

Intergovernmental agreements have been signed between Bulgaria, Serbia, Greece, Hungary, Slovenia, Croatia and Austria for the implementation of the section of the pipeline that will run over land.

Russia and Bulgaria signed an agreement on the South Stream project in January 2008, and both financial and technical preparations were scheduled to be put together by mid-2010.

However, until recently, Bulgaria's participation in the project was uncertain. Borisov announced a suspension in the project when he came to power in summer 2009 and has been making inconsistent statements on the project ever since.

MOSCOW, July 17 (RIA Novosti)