Specialty Fashion Group will shutter over 300 stores as part of a restructure.
The company, behind brands such as Katies and Millers, revealed the closures at an annual general meeting this week.
Chairwoman Anne McDonald addressed the restructure amid declining sales and increased competition.
“We are targeting an optimised store network of around 700 stores in 2020 compared to the current 1,000-plus stores,” she said.
Specialty Fashion Group currently has a portfolio of 1,019 stores.
The company's full year loss for 2017 grew four-fold to $8.39 million, heightened by the exit of its City Chic stores in the US.
The group has reduced costs by $3.6 million in the first quarter of the 2018 financial year through a "leaner support office."
CEO Gary Perlstein has also announced he will be stepping down after 14 years in the role.