Italian energy company Eni said Tuesday it signed what it said was a groundbreaking deal to sell liquefied natural gas from a deepwater Indonesian field.

Eni and its partners at French energy company Engie, formerly GDF Suez, and its Indonesian partners signed a deal to purchase and sell as much as 1.4 million tons of LNG per year from the Jangkrik complex starting in 2017.

"The signing of these agreements represents a key milestone for the Jangkrik field development project," Eni Chief Executive Officer Claudio Descalzi said in a statement. "It is one of the first deep-water gas projects in Indonesia being developed under a fast track scheme, and confirms Eni's commitment in supplying gas for the development of the Indonesian domestic market."

An October report on Southeast Asia from the International Energy Agency said the region's energy demand is expected to soar by more than 80 percent through 2035.

IEA says the region will need around $1.7 trillion of investment in energy infrastructure in the period to 2035.

The French company last year signed a cooperation agreement with its regional counterparts, Perusahaan Gas Negara, related to a feasibility study for the LNG terminal in northern Java.

Natural gas production in Indonesia increased by more than 20 percent in the decade ending in 2012, the U.S. Energy Information Administration reports. The country exports about half its natural gas and is one of the largest exporters of liquefied natural gas in the world.

Eni said field development included pipeline development and offshore production terminals. Production is expected to begin at the Jangkrik development by 2017.