Refer to the input text as context and select the correct relationship between 'Energy company' and 'natural gas' from the available options.
Options: stock exchange, operator, product/material produced, business division

Energy company BG Group (LSE: BG.L - news ) has started up and loaded its first liquefied natural gas from the second production train at the Queensland Curtis LNG (QCLNG) facility in Australia.
product/material produced