Russian state-owned energy giant Gazprom and Bulgaria signed a final deal on Thursday to build the Bulgarian stretch of the South Stream gas pipeline project to bring Russian natural gas to Europe along the Black Sea seabed bypassing transit countries. The deal was signed during a working visit by Gazprom CEO Alexei Miller to Bulgaria. “In the presence of Bulgarian Prime Minister Boyko Borisov, Alexei Miller and Bulgarian Energy Holding’s Mikhail Andonov signed a protocol on the final investment decision to build the South Stream gas pipeline in the territory of Bulgaria,” Gazprom said in a statement relayed by Russian Ria-Novosti news agency today. The deal crowns Gazprom’s efforts to sign final investment decisions on the South Stream gas pipeline’s overland sections in Bulgaria, Hungary, Serbia and Slovenia, and its offshore section in the Black Sea. The South Stream pipeline will transport up to 63 billion cubic meters of natural gas to central and southern Europe along the Black Sea seabed, diversifying Russian gas routes away from transit countries such as Ukraine. The offshore section of the South Stream gas pipeline will run under the Black Sea from the Russkaya compressor station to the Bulgarian coast. The total length of the Black Sea section will exceed 900 kilometers (559 miles) and its maximum depth will be more than two kilometers. Following Russian President Vladimir Putin’s orders, Gazprom has accelerated the South Stream pipeline’s construction schedule, with work now to begin before the end of 2012. The pipeline’s commercial deliveries of natural gas to Europe are expected to start in the first quarter of 2016 and the project is set to reach its designed capacity of 63 billion cu m in 2018. The project’s cost, including the pipeline’s overland sections, is estimated at 16 billion euros ($20 billion).