In its latest move to expand a multi-billion-dollar stake in Mexico, San Diego-based Sempra Energy’s Mexican subsidiary, Infraestructura Energetica Nova SAB de CV (IEnova) acquired an additional 25% interest in the Los Ramones II Norte natural gas pipeline from Petróleos Mexicanos (Pemex) for $231 million, plus assumption of outstanding debt.

The IEnova acquisition doubles its participation in the U.S.-to-Mexico pipeline supplying fuel for gas-fired power plants. Sempra expects its latest deal to close before the end of this year.

Sempra will assume $289 million of debt for the added 25% interest, representing Pemex’s portion of the pipeline’s overall outstanding debt. At the end of 2016, IEnova had more than $7 billion in assets throughout Mexico’s energy infrastructure, according to a Sempra spokesperson.

The entire 2.1 Bcf/d Los Ramones pipeline runs from Agua Dulce, TX, and is about 621 miles long. The nearly 400-mile, 42-inch diameter Norte portion interconnects with Los Ramones I pipeline and the Los Ramones II Sur pipeline in central Mexico.

Los Ramones II Norte has a 1.42 Bcf//d capacity and two compressor stations, running from Nuevo Leon to San Luis Potosi.

“Los Ramones II Norte is located in northeast Mexico, and it contracts with Cenagas to supply gas to fulfill its various system/network needs, including providing gas to some power plants,” the spokesperson said.

Investment continues to flow into new pipeline infrastructure to increase U.S. gas supply to Mexico. Late last month, Texas Gov. Greg Abbott hosted a meeting with top Mexico officials and energy executives to discuss oil and natural gas trade across the border.

Two years ago Abbott signed a transportation agreement between the Texas Department of Transportation and the Ministry of Communications and Transportation of the United Mexican States to promote collaboration on border infrastructure projects.

Mexico is the Lone Star State’s biggest trading partner, and Texas exports more goods to Mexico than any other state, according to Abbott’s office.

The total capacity of all U.S.-Mexico natural gas pipelines grew to 7.8 Bcf/d in 2016, compared with 3.7 Bcf/d in 2011, and is expected to double by 2019, according to the Federal Reserve Bank (FRB) of Dallas. Natural gas exports to Mexico increased to 3.8 Bcf/d in 2016 from 1.4 Bcf/d in 2011, reflecting the growing pipeline capacity.

More than 1 Bcf/d of U.S. gas exports moved through Rio Grande City, TX, where the NET Mexico pipeline connects with Mexico’s Los Ramones project, FRB said.