Exxon Mobil Corp. said that it would buy a 25% indirect interest in an offshore natural gas field near Mozambique from Eni SpA for about $2.8 billion.

The deep water "Area 4" block contains an estimated 85 trillion cubic feet of natural gas.

Eni currently holds a 50% indirect share in the field through a 71.4% stake in Eni East Africa, which owns 70% of the Area 4 concession.

Following the deal, Eni East Africa will be co-owned by Eni with a 35.7% stake, Exxon with 35.7%, China National Petroleum Corp. with 28.6% and other investors.

Eni will continue to lead the floating liquefied natural gas project and all upstream operations in Area 4, while Exxon will lead the construction and operation of natural gas liquefaction facilities onshore.