Eni's discovery of potentially the world's largest natural-gas field off the Egyptian coast will be a gamechanger for Egypt and the Mediterranean in terms of energy stability, the CEO of the Italian energy giant told CNBC on Monday.

On Sunday, Eni said in a press release that it had discovered a "supergiant" gas field that could hold "a potential of 30 trillion cubic feet of lean gas in place." It said the discovery well was located off Egypt's Mediterranean coastline at a depth of 1,450 metres with the prospective Zohr field covering an area of about 100 square kilometres (60 square miles).

Eni said that the discovery could satisfy Egypt's natural gas demand for "decades".

On Monday, Claudio Descalzi, CEO of Eni, told CNBC: "It is changing the game for Egypt…It is very important for Egypt, but also for the Mediterranean in terms of stability."

Descalzi could not give a timeline for when the gas might hit the market, but said developments would be quick as the gas field was in close proximity to Eni's processing facilities.

"It is close to the facilities so the time to market will be very good… that is part of our strategy to…continue to do our exploration in the mature area where we have a deep geographical knowledge and we can take advantage of our facilities and that will make the unit cost in terms of capital very positive," the CEO said.

"I don't want to put a date now but it is a question of a few years to have production—then a full production, that will be a very quick fast track development," Descalzi added.