The company signed a binding heads of agreement with the WestSide-operated Meridian SeamGas coalbed methane joint venture.
Gas supply will start in 2015 and will be supplied over a 20-year period at an oil-linked price from 2016.
The gas will be piped from the Meridian gas fields in Queensland and delivered to GLNG’s gas transmission pipeline.
GLNG is one of three LNG projects being built on Curtis Island off Queensland, which were thought to be struggling for mid-term gas supply.
According