A 12-month gas supply lifeline for Incitec Pivot's threatened Gibson Island fertilisers plant in Queensland is expected to wipe out profits at the operation next year, while its longer-term future still hinges on the success of a $20 million gas development venture with junior producer Central Petroleum.

Incitec will buy 32 terajoules a day of gas, to be supplied from the Mereenie gas field near Alice Springs jointly owned by Central and Macquarie Group, and from Central's Palm Valley field nearby.