The pipeline's design is based on a trilateral agreement signed in March 2007 in Athens by Putin, then Greek Prime Minister Costas Karamanlis and former Bulgarian Prime Minister Sergei Stanishev.
Nacrt naftovoda zasnovan je na trilateralnom sporazumu koji su u martu 2007. u Atini potpisali Putin, tadašnji grčki premijer Kostas Karamanlis i bivši bugarski premijer Sergej Stanišev.