Fujitsu named preferred partner.
Australia Post will soon take plans to outsource 108 internal technology jobs to Fujitsu to its board for approval.
The plans to offload the functions of AusPost's end user computing and enterprise technology services teams to an external provider were first revealed in September last year.
At the time, the Communications Workers Union warned that reductions would add to the 900 jobs in management, administration and support areas already in the firing line before June 2015.
The outsourcing decision would affect around 108 workers within the organisation's 1200-strong IT division.
The union criticised AusPost's consultation with workers as "box ticking exercises", which had forced the CWU to go to the Fair Work Commission late last month.
"Obviously the workers affected are very disappointed by Post’s decision," the CWU said in a statement.
"Some have been through a restructure last year. There can be no guarantees that work won’t be offshored."
The positions are likely to be outsourced to Fujitsu, which has been named the preferred supplier.
AusPost's initial plans to take the Fujitsu proposal to the board in May have been held back to June, the CWU said after AusPost agreed to develop an alternative option to the outsourcing.
"We have told Post that the decision to outsource EUC is not well thought out. The alternative proposals put by workers and their union should be trialled for 12 months," the CWU said in a statement.
"Post should go back to the drawing board and examine who and what must be kept because they are critical to the organisation."
The union said it had been advised by AusPost that the expected savings from the outsourcing agenda would sit somewhere between $5 million and $8 million.
An Australia Post spokesperson told iTnews a decision on the proposed outsourcing had not yet been made.
"Just like many businesses, Australia Post is operating in a challenging business environment. We will continue to assess our services against the market to ensure we are delivering value to our business and our customers."
Australia Post was aiming to achieve four key objectives through the Fujitsu partnership, according to the CWU.
It said the organisation was after confirmed pricing for specific service options; the ability to add and remove resources quickly as needed; access to new technologies; and faster speed to market for new products.