A consortium led by U.S. energy giant Chevron has signed lease agreements with the Greek government to begin natural gas exploration in deep waters off southern Greece, marking a major step in the country’s push to strengthen energy security.

The contracts, signed in Athens on Monday, grant the group exclusive rights to explore four offshore blocks located south of the Peloponnese peninsula and the island of Crete. Together, the areas cover about 47,000 square kilometres and significantly expand Greece’s offshore exploration footprint.

Greek Prime Minister Kyriakos Mitsotakis attended the signing ceremony, alongside senior government officials and executives from consortium partners, including HELLENiQ ENERGY, Greece’s largest oil refiner.

The deal comes as Europe continues efforts to reduce reliance on Russian gas supplies following the Ukraine war. Greece, which currently produces no natural gas and depends heavily on imports, has renewed interest in domestic exploration after energy prices surged in 2022.

Chevron’s entry further deepens U.S. involvement in the eastern Mediterranean energy space.

The company is already expanding gas production in Israel and now takes the lead role in Greece’s latest offshore search. Another U.S. major, Exxon Mobil, is also active in Greek waters through a separate partnership exploring blocks west and south of Crete.

Beyond exploration, Greece is positioning itself as a transit hub for American liquefied natural gas entering Europe.

Through the Vertical Gas Corridor, LNG arriving at Greek terminals can be transported northward to central Europe and Ukraine, supporting broader European Union energy diversification plans.
The newly signed leases must still be ratified by the Greek parliament. Once approved, seismic surveys are expected to begin later this year.

Authorities say the consortium has up to five years to identify commercially viable gas deposits, while any exploratory drilling is unlikely before 2030.

European officials continue to stress that while renewable energy capacity is expanding, natural gas will remain an important transition fuel to maintain grid stability as wind and solar output fluctuates.