March 30 (LNGJ) - Sempra Energy, the owner of LNG terminals in the US state of Louisiana and northern Mexico, has agreed to sell its 25 percent interest in the Rockies Express Pipeline (REX) for around $440 million in cash to Tallgrass Development of the US. “While REX is an important part of the country's natural gas pipeline system, we believe that given the changing market conditions, we can more productively redeploy the proceeds from the REX sale into long-term growth opportunities,” said Sempra. The REX is one of the largest natural gas pipelines ever constructed in North America. The 1,712-mile transmission line extends from Opal, Wyoming, and Meeker, Colorado, to Clarington, Ohio.