Australian gas producer Senex Energy has unveiled plans to invest more than A$1bn ($708m) to increase output from gas fields in Queensland.

The proposed investment will be used to expand the Atlas and Roma North natural gas developments in the Surat basin of Queensland.

Senex is controlled by South Korean trading company Posco and Hancock Energy and started producing gas in Queensland three years ago.

The investment is expected to boost the company’s annual output to 60 petajoules (PJ) per year by 2025.

Senex CEO Ian Davies said: “This new investment to significantly boost domestic natural gas supply supports Australia’s energy security and continues to underscore Queensland’s position as a reliable energy provider.

“Senex prides itself on supporting the production of natural gas for the Australian market. It was only three years ago Senex began supplying the east coast market from Queensland’s Surat basin and to date has already invested more than half a billion dollars in new supply.”

The company plans to invest over two-thirds of the capital commitment over the next two years in gas infrastructure and wells at its Surat basin developments.

Posco International agreed to acquire all the shares of Senex Energy in a $610m deal in December 2021.

Davies also revealed that the company’s new owners Posco International and Hancock Energy have committed to injecting ‘significant’ additional new capital to allow Senex to bring ‘critical new gas’ supplies to market.

The bulk of the extra fuel will be reserved for domestic use to help secure Australia’s energy future, the company said.