Origin has agreed to purchase up to 139 petajoules of gas under the 2013 agreement.

Beach is supplying the gas from its share of production from the South Australian Copper Basin Joint Venture and the South-West Queensland JV that it shares with Origin and Santos.

Beach will be paid for the gas at an attractive oil-linked pricing.

Origin has the potential to extend the contract for a total of 173 petajoules 10 years.

It is expected that sales gas delivery under the Long Term GSA will ramp up during FY16, while legacy contracts continue to be serviced.

"We are pleased to have partnered with Origin for the supply of material gas volumes under a long term gas sales agreement," Beach managing director Rob Cole said.

"Our transition to separate gas lifting and marketing from the Cooper Basin will strengthen both Beach's position as an independent upstream gas supplier, and our ability to benefit from expected East Coast gas demand growth."

The contract is one of a number that the Queensland LNG plants have entered into to offset ramp-gas and performance risks from the Bowen-Surat Basin CSG fields, and retails such as Origin secured to ensure that they can meet domestic gas contracts.