Centrica will buy 1.75 million metric tons a year of liquefied natural gas from Cheniere Energy Inc.'s Sabine Pass plant in Louisiana, the Windsor, England-based company said today. That's equivalent to the demand of 1.8 million U.K. homes. The deal can be extended for another 10 years, it said. Prices will be linked to Henry Hub, the U.S. benchmark gas prices, and deliveries will start in September 2018. The deal shows the U.S.'s emergence as a natural gas exporter after fracking technology created a glut of fuel, sending prices to decade lows. In contrast, U.K. gas prices spiked to a seven-year high last week after a fault on a Belgian pipeline, raising concern that Britain is vulnerable to supply shortages as indigenous production slumps.