HOUSTON, July 9 (Reuters) - U.S federal regulators on

Tuesday upheld an earlier decision to allow LNG developer

Tellurian a three-year extension to construct its

Driftwood LNG plant on the west bank of the Calcasieu river,

near Lake Charles, Louisiana.

The U.S. is the world's largest exporter of the superchilled

gas and Tellurian is one of dozens of U.S. companies trying to

develop LNG export facilities.

(Reporting by Curtis Williams in Houston)