TotalEnergies TTEF.PA of France and Italy's Eni ENI.MI on Monday announced a significant natural gas discovery at the Cronos-1 well off Cyprus.
The island reported its first natural gas discovery, Aphrodite, in 2011, measuring around 4.5 trillion cubic feet (tcf) and now run by U.S. energy firm Chevron.
"Preliminary estimates indicate about 2.5 tcf of gas in place, with significant additional upside that will be investigated by a further exploration well in the area," Eni said in a statement regarding the latest discovery.
It marks the third offshore gas find reported in waters off Cyprus, all of them still untapped, and comes as the European Union seeks alternative supply to Russian gas after Moscow's February invasion of Ukraine.
Cyprus and the companies are 'already processing ways to expedite and optimise use of this new discovery, (which will) contribute to efforts of Europe in boosting its energy security,' Cyprus's Energy Ministry said.
Sector rivals Exxon and Qatar Petroleum are also drilling in the east Mediterranean region where gas output has soared as older discoveries finally bear fruit.
An appraisal well reaffirmed a reservoir of high quality gas in another area south-west of the island, Cypriot authorities said in March.
EU member Cyprus, however, has faced strong objection from Turkey over its offshore exploration programme, with overlapping claims of jurisdiction extending from land to sea.
The island was divided after a 1974 Turkish invasion in response to a brief Greek inspired coup.
"This successful exploration well at Cronos-1 is another illustration of the impact of our exploration strategy which is focused on discovering resources with low technical cost and low carbon emissions, said Kevin McLachlan, senior vice president for exploration at TotalEnergies.
He said additional sources of gas supply would contribute to Europe's energy security.
"Studies on a fast-track development options are already ongoing," Eni said.
TotalEnergies and Eni began drilling work at the Cronos-1 prospect in offshore Block 6 in May. In 2018 they reported a 'promising' gas discovery at Calypso-1, another well in Block 6.
They are collaborating via local units Eni Cyprus and TotalEnergies EP Cyprus BV and each hold a 50% stake.
(Reuters - Reporting by Tassilo Hummel and Juliette Portala; additional reporting by Michele Kambas editing by Sudip Kar-Gupta and Jason Neely)