President Traian Basescu declared that the discussions with his Serb homologue, Boris Tadic, included the future of the Constanta-Trieste oil mainline project. Along with Nabucco, this is the most important energy project currently involving Romania.

The future European mainline is supposed to begin in the Constanta harbor, cross some of the future Yugoslavia states (Serbia, Croatia and Slovenia), reaching the Italian harbor of Trieste. The oil would be bought from the Caspian and Central Asia sources.

In April 2007, the countries involved in the project signed an agreement on the construction of the future oil pipeline. According to project, the pipeline would be 1,856 kilometers long and should start by transporting 40 million tons of oil per year, reaching a maximum capacity of 90 million tons in the future. The estimated cost is between 2.62 and 3.96 billion euro.

The project is competing with a Burgas-Alexandroupolis pipeline project which has the strong support of Russia.