Greece and Italy will sign an agreement on maritime boundaries during a visit by Italy's foreign minister to Athens on Tuesday, the Greek Foreign Affairs Ministry said.
The deal follows months of tensions in the Eastern Mediterranean region over natural resources. Turkey, Greece and Cyprus have been caught in a complex diplomatic standoff over the issue.
Details of the deal were not immediately available.
Italian Foreign Minister Luigi Di Maio and his Greek counterpart Nikos Dendias are expected to make a joint statements following their meeting.
At a meeting in Rome in February, the two ministers discussed ways of cooperating in the energy sector in the eastern Mediterranean.
Italy and Greece are already partners in the EastMed gas pipeline project intended to transport 10 billion cubic meters of gas per year from off-shore gas reserves in the eastern Mediterranean to Greece, Italy and other southeastern European countries.
The accord between the two countries comes months after a deal on maritime boundaries between Turkey and Libya's Tripoli-based internationally recognized government. That agreement angered Greece, which views the move as infringing its own sovereign rights.
Greece and Turkey are at odds over various decades-old issues ranging from mineral rights in the Aegean Sea to ethnically split Cyprus.
(Reporting by Renee Maltezou and James Mackenzie; Editing by Alison Williams)