ExxonMobil LNG Asia Pacific tied up the agreement to buy the LNG from a proposed third train, or production unit, at the Saguaro Energia project on Mexico's west coast, Mexico Pacific said in a statement.
Under the new deal, Exxon will buy the LNG on a free-on-board basis over a 20-year term.
With the agreement, Houston-based Mexico Pacific has locked in the sales required to make a final investment decision later this year on building the third train, CEO Ivan Van der Walt said in the statement.
The new pact follows on a deal late last year under which Exxon agreed to buy about 2 million tonnes per annum from Saguaro Energia's first two LNG trains.
The Saguaro Energia project is set to ship 15 million tonnes per annum of LNG to Asia, using gas from the U.S. Permian Basin. The project has a price tag of over $15 billion, officials from the Mexican state of Sonora said last year.
