Greek authorities approve Chevron's entry into Block 10 offshore Kyparissiakos Gulf
All administrative approvals have been completed for Chevron to acquire a 70% stake and the operator role in Block 10, a concession in the Kyparissiakos Gulf, forming a joint venture with HELLENiQ ENERGY.
On 15 June 2026, the Greek Ministry of Environment and Energy, the Hellenic Hydrocarbons and Energy Resources Management Company (EDEYEP), and the Ministry of Foreign Affairs approved Chevron's entry into the Block 10 concession in the Kyparissiakos Gulf, southern Ionian Sea. The approval follows a joint request by Chevron and HELLENiQ ENERGY submitted on 28 May. The meeting in Athens was attended by Minister Stavros Papastavrou, US Ambassador Kimberly Guilfoyle, EDEYEP CEO Aristofanis Steftos, Chevron's Andrew Deighan, and HELLENiQ ENERGY CEO Andreas Siamisiis, among others. A 15-month extension of the second research phase was also submitted by the operator.
Concession structure
Once the farm-in agreement is completed (expected within the next few days), Chevron will hold a 70% stake and assume the operator role in Block 10, while HELLENiQ ENERGY retains a 30% interest. The block had originally been granted to HELLENiQ ENERGY, which is now transferring the majority stake.
Exploration progress
The first and second research phases of the Basic Research Stage have been concluded, covering geological, geophysical, and environmental studies. A 2022 campaign acquired 1,210 km of 2D seismic data, expanding the available database by 40%, followed by the first-ever acquisition of 2,416 square kilometers of 3D seismic, covering 88% of the concession. The new consortium will jointly evaluate these datasets to decide on entering the third research phase, which involves an exploratory drilling.
Wider exploration program
The Chevron–HELLENiQ ENERGY consortium already holds lease agreements for four additional offshore areas, south of Crete and south of the Peloponnese. Block 10 becomes the fifth concession where the two companies cooperate in Greek hydrocarbon exploration. Minister Papastavrou described the approval as another important step for the responsible exploration of the country's mineral wealth.
