"The deal is done but won't be announced for several months at Exxon's request," one of the sources said.
Eni declined to comment, while a spokesman for ExxonMobil said: "We do not comment on market rumours or speculation".
The offshore gas reserves already discovered by Eni in Area 4 are large enough to need a giant land-based LNG export plant whose proximity to Asian and Middle Eastern growth markets makes it potentially a highly-lucrative project.
But
