Cheniere Energy Inc.'s (NYSE: LNG) Sabine Pass LNG export plant on the U.S. Gulf Coast will shut down for planned maintenance in September, sources with knowledge of the matter said.

The exact timing of the shutdown has not been set yet, one of the sources said on July 19.

The plant, which started-up in February and has exported 18 cargoes to date, can produce around 4.5 million tonnes of LNG per year from its one existing production line, known as train 1.

Spot LNG prices have risen 40% since March to around $5.75 per million British thermal units, driven by production outages in Australia and rising oil prices.

The second LNG train at Cheniere's Louisiana plant will likely enter service by the end of August, according to market intelligence firm Genscape.