Papua New Guinea's national court has ordered the merger agreement between Oil Search and Santos be binding, and that the merger should take effect from 10 December.

The court made the orders on 9 December, approving the scheme of arrangement under which Santos will acquire all of the shares in Oil Search in return for the issue of new Santos shares to Oil Search shareholders.

Court approval is the final step in the regulatory process following on from the PNG competition watchdog approving the merger on 8 December, and Oil Search shareholders accepting the takeover on 7 December.

Oil Search said it intends to apply for its shares to be suspended from trading on the PNG and Australian stock exchanges with effect from the close of trade on 10 December.

Santos said in a filing to the Australian bourse it proposes to issue 1.3 billion new Santos shares.

Oil Search shareholders will be issued 0.6275 new Santos shares for each fully paid ordinary Oil Search share; giving Oil Search shareholders a 38.5% ownership in the merged company and existing Santos shareholders 61.5%.

The combined company will have a pro forma market capitalisation of more than A$20 billion,

Combined proven plus probable reserves and best estimate contingent resources will be nearly 4.9 billion barrels of oil equivalent, while 2020 production would be 118 million boe, with a power base of production and development projects in Australia and PNG.