Telstra is reportedly sacking 650 staff from its Sensis business division, which runs Yellow Pages, White Pages and Trading Post.
The jobs will be axed from offices in Sydney and Melbourne.
“We're talking to members at the moment and we will be meeting th Sensis at 3pm,” Community and Public Sector Union spokesman Teresa Davison told News Ltd.
She said 2500 staff work for Sensis, which has reportedly been hit by a fall in advertising revenue, particularly within its print publications.
“Like all large businesses they look at their massive profits dropping,” Ms Davison added.
“If a $1 billion profit drops to $900 million their response is to sack staff, even though they are still making a huge profit.”
Sensis appointed digital media executive Jeremy Birt as its new executive general manager on January 30, with a brief to oversee the company's print and digital operations.
The company also acquired True Local in January and indicated the online directory would be added to its Yellow Pages network.
The deal was subject to ratification by the Australian Competition and Consumer Commission.
Comment is being sought from Telstra.