Cheniere Energy Inc., the only company sending America’s shale gas overseas, has begun liquefying the fuel at a fourth plant, keeping the company on a track that will double its export capacity this year. The plant at Cheniere’s Sabine Pass complex in Louisiana is chilling and condensing gas into a liquid so it can be loaded onto tankers, a person familiar with the situation said, asking not be identified because the information isn’t public. The Houston-based company is already producing liquefied natural gas from three plants at the terminal and is working to bring the fourth fully into service by the end of the year. The startup of the fourth plant stands to unleash even more U.S. gas into a worldwide market already awash with supplies. Since beginning operations early last year, Cheniere has sent cargoes of shale gas to about two dozen countries from Chile to China. That’s delivered some relief to U.S. gas drillers who are increasingly looking abroad for sources of demand and has bolstered domestic gas prices this year. Cheniere declined to comment. The company said in a June 9 presentation that it expected the fourth plant to be substantially complete in November. Pipeline deliveries of natural gas to the Sabine Pass terminal this year are already more than double what they were in 2016, according to ABB Inc. data compiled by Bloomberg. Cheniere is now taking about 2 billion cubic feet a day out of the U.S. market. The fourth plant still needs to be commissioned—when Cheniere’s contractor hands over operations to the company. That process, which can take months, is a key step in beginning Cheniere’s 20-year supply contract with Gail India Ltd. The first three trains at Sabine Pass are contracted to Royal Dutch Shell Plc, Spain’s Gas Natural SDG SA and Korea Gas Corp.