It marks the start of the physical installation of the Coral Sea Cable System, Australia's Foreign Affairs Department said.
Australia will deliver and fund the most of the cables, with a financial co-contributions from both PNG and Solomon Islands.
"Australia's strong support for this project is a reflection of our enduring commitment to the Pacific, where we work with partners to support the region's stability, security and prosperity.
"Boosting connectivity in PNG and Solomon Islands will drive economic growth, and improve governance and security. World Bank research estimates improved internet access and connectivity could grow GDP by more than US$5 billion and create close to 300,000 new jobs in the Pacific by 2040," Foreign Affairs said.
The Coral Sea Cable System is scheduled for completion by the end of 2019.
