Editor’s Note: NGI’s Mexico Gas Price Index, a leader tracking Mexico natural gas market reform, is offering the following column by Eduardo Prud’homme as part of a regular series on understanding this process.

For a while now, CFE Internacional (CFEi), a company incorporated in 2016 in Delaware, has been among the 15 largest marketers of natural gas in North America. According to the latest NGI Top North American Natural Gas Marketers rankings, in the second quarter this U.S. subsidiary of Mexico’s state utility Comisión Federal de Electricidad (CFE) ranked an impressive 12th with transactions that averaged 3.8 Bcf/d during the period.

CFEi imports gas into Mexico. CFEnergia, meanwhile, is the Mexican company in charge of marketing this purchased natural gas. It...