South Stream is envisaged as a set of four parallel pipelines of 931 kilometres each, linking Russia and Europe with a total annual throughput capacity of 63 billion cubic metres of gas.

The Brussels-based EC, which is the executive branch of the 28-member state EU, had previously said in December that the South Stream pipeline was in breach of EU competition law and bilateral deals with its calling points - Bulgaria, Serbia, Hungary, Greece, Slovenia, Croatia and Austria - all needed to be redrawn.