But the company said in response to a query from iTWire that Virgin Mobile Australia employees would be considered for vacancies in Optus-owned stores.
They would "also be invited to explore opportunities within our group of companies", a spokesperson said.
Rumours of the phasing out of Virgin Mobile were floating around in April, but at that time when an inquiry was made, Optus said it was unwilling to comment on what it characterised as "rumour and speculation".
The spokesperson said: "Virgin Mobile customers can continue to use their service in the same way they always have. We will be contacting them in the coming days to let them know more about the changes and their future options.
"For Virgin Mobile employees, our policy is always to talk to those who may be impacted by these changes first. Any potential options for redeployment within the wider Optus business will be discussed with affected individuals at that time."
Founded by Sir Richard Branson in 2000, Virgin Mobile Australia became a wholly-owned subsidiary of Optus in 2006.
Maintaining its own brand, it offers post-paid mobile and mobile broadband services to about a million Australians.