The ports of Trieste and Koper are north of the Istria peninsula, about 15 kilometres from each other.
Together with Slovenian Prime Minister Janez Jansa, Prodi told a joint news conference that there should be a single port in the Trieste bay.
“Trieste and Koper are in fact the same port on the opposite sides (of the bay),” said Prodi.
Reports say that with Slovenia's entry into the EU in 2004 and its upcoming integration into the EU's Schengen visa regime, administrative obstacles facing a merger between the two ports should be considerably reduced.
Prodi added that the merger should also include the north Croatian Adriatic port of Rijeka, situated approximately 80 kilometres south of Koper.
“Through such a project, the three ports could work as a single port on the Adriatic Sea and would create a significant economic space,” said Prodi.
Prodi expects the collaboration to present competition to the northern European transshipment hub ports of Rotterdam, Antwerp and Hamburg.
Industry players say cargo from Asia going through the Suez Canal could use a fully-developed Adriatic port facilities as the new gateway port to inland European markets.