Tuesday's shipment was in response to an emergency request by the Thai company, BPMigas chairman R. Priyono told reporters.
"It was sold at market price," said Priyono, adding that the shipment was a one-off delivery.
BPMigas said PTT had requested to buy one cargo of LNG after a leak from one of the company's offshore gas pipelines last month.
PTT has said it planned to import more LNG to offset the supply losses. The natural gas leak in the Gulf of Thailand could result in a loss of about 600 million cubic feet per day (mmcfd), accounting for around 14 percent of PTT's total gas supplies in the country, which uses natural gas to generate 70 percent of electricity.