UPDATE 1-LNG expansion may not go ahead-Trinidad official

(Adds detail, quote, background)

BUENOS AIRES Oct 7 (Reuters) - Expansion of Trinidad and Tobago's liquefied natural gas production may not go ahead because there is currently not enough extra gas, David Small, director of policy at the Ministry of Energy, told Reuters on Wednesday.

The possibility of a fifth train to add to the first four at Atlantic LNG has been on the table for some time, but Small said that it will not definitely go ahead.

"As of now, the gas is not all there for an expansion," Small said on the sidelines of the World Gas Conference. "It is not automatic that there will be a fifth train at Atlantic LNG."

Trinidad is the principle LNG supplier to the United States. Atlantic LNG's first four trains have differing shareholder structure. Stakeholders include BG Group (BG.L), BP PLC (BP.L), GDF Suez (GSZ.PA) and Repsol YPF (REP.MC).

Demand for LNG has slipped this year as the economic downturn took hold, but Conrad Enil, Trinidad's energy minister, told reporters Wednesday that Trinidad had not cut back onproduction.

(Reporting by Edward McAllister and Robert Campbell; Editing by David Gregorio)