The company will make 290 of the 440 roles redundant and create 150 new positions, The Australian reported.
This is the third time Optus has announced sackings this year.
The telco said in May that it was phasing out its Virgin Mobile subsidiary and that 200 positions would go.
Contacted for comment, an Optus spokesperson said: "Optus is committed to becoming a world-class, mobile-led, digital service provider.
"As we continue to evolve the way we work, do business and fund future investments we are removing duplication, improving our operating efficiency and embracing next-generation technologies, like digitisation and automation to achieve this goal.
"As a result, certain roles will be impacted, including 440 roles being made redundant.
"We are speaking with affected employees first, and discussing redeployment opportunities where available.
"We are structuring our organisation to become the next-generation Optus and continue to meet the needs of our customers."