In yet another effort to enhance European energy security by diversifying sources away from Russia, a consortium of countries including Cyprus, Italy, Greece and Israel will build an 1900 km gas pipeline from the Levantine Basin in the eastern Mediterranean to Greece and Italy in 2025.

The East Med Pipeline, as it is being called, would ship up to 16 billion cubic meters (bcm) of gas a year, roughly 5 percent of the EU annual consumption.

IGI Poseidon, a joint venture by Italian firm Edison and Greek company Depa, will build the pipeline - the longest underwater one in the world - at a cost of over €4 billion.

The EU has indicated that it will defray $2 billion, of half the cost, of the construction.

Cyprus, Israel, Italy and Greece intend to sign a binding intergovernmental agreement in 2018.

The Greek minister, Giorgos Stathakis, said "today we are making a major step forward" in a project that would be "strategically very important for Europe". And the Israeli energy minister, Yuval Steinitz, said: "It looks like a fantasy, a dream, because there is no parallel, there is no such long and deep underwater gas pipeline in the world, and now, we can understand that this is possible, viable."

The eastern Mediterranean has produced some of the world's biggest gas finds in the past decade, and much of it is still thought to be untapped at a time Europe is looking to diversify its gas resources and bolster energy security. The field within Israel's territorial waters alone contains as much as 900 bcm of natural gas.