US oil major ExxonMobil, Energean and Helleniq Energy will sign a contract on Wednesday with Stena Drilling to start exploratory drilling in a western Greek offshore block, Greece's energy ministry said on Tuesday.
ExxonMobil, Energean and Greece's biggest oil refiner Helleniq announced an agreement last year to explore for natural gas in Block 2 in the Ionian Sea.
The consortium will proceed with exploratory drilling in February 2027, a Greek energy ministry official said on condition of anonymity, the country's first offshore exploration drilling in 40 years.
Stena will use a high-performance vessel able to operate in deep-sea waters and drill at a depth of up to 35,000 feet to look for deposits once considered hard to access, the official said.
Europe is attempting to diversify its energy sources as it seeks to replace Russian gas following Russia's invasion of Ukraine.
(Reporting by Angeliki Koutantou; Editing by Jan Harvey)