Nobel Energy from the United States is leading a consortium probing the Leviathan prospect about 84 miles off the northern Israeli coast. Preliminary figures indicate the prospect holds as much as 16 trillion cubic feet of gas.
Gideon Tadmor, an executive at Israeli partner Delek Energy Ltd., said the find is transformative for the region.
"We see a huge revolution in the Israeli energy sector," he was quoted by The Wall Street Journal as saying.
Lebanon, meanwhile, contends that a portion of Leviathan lies within its maritime borders. Hezbollah has told Israel not to touch its resources, spurring threats of force from the Israelis.
The potential at Leviathan follows the 2009 discovery of the Tamar gas field off the Israeli coast, which holds around 8 trillion cubic feet of gas.