According to the Cyprus News Agency, the agreement on the pipeline, which will connect Israel, Cyprus, and Greece, needs the approval of the European Commission first.
The agreement also contains important references to the security of energy infrastructure.
As part of the deal, the three countries will set up a permanent secretariat in Nicosia whose job will be to coordinate the trilateral cooperation scheme.
It has received €35m in funding from the European Commission as a Project of Common Interest (PCI). The pipeline is currently designed to initially carry 10 billion cubic meters (bcm) a year from the East Med to Greece, about 1,900km, where it will connect to the Poseidon pipeline to Italy, about 300km.
Some industry experts believe the four governments and the EU cannot fund the project, which would require investor participation, and buyers for its gas.