Costco, which operates more than 1,600 stores across Australia, is shutting about 400 stores across Queensland and New South Wales in a bid to slash costs.
Costco Australia confirmed on Thursday that its stores will close in Sydney on Saturday.
It said it would shut in Brisbane on Friday.
There will be an estimated 4,200 direct and indirect jobs lost in Sydney, and about 1,200 jobs lost from Brisbane, according to the company.
Costco says the closures are part of the company’s ongoing commitment to reduce costs.
“Costco is committed to reducing our workforce and supporting our employees through this transition,” it said.
“We expect to have all stores open by Christmas.”
Costco Australia said in its statement that “some of the stores that will be closing will be located in Australia’s major cities.”
“Costco has always been about the long-term health of our company, and we continue to look at every opportunity to further our growth strategy,” it added.
The announcement comes as the retailer’s parent company, the Wal-Mart Stores Inc, announced plans to buy its struggling Australian operations.
The move will make it more powerful and potentially allow it to take advantage of the rising popularity of online shopping.
Costos decision is a major blow to the Australian retail industry, which has been struggling to adapt to the rise of online sales and a shifting consumer culture.
It has been forced to slash its Australian workforce by more than 20 per cent over the past year.
The company has about 2,100 people working in Australia and its online stores, where prices vary widely, are the second-largest employer in the country.
The loss of retail jobs could also have a ripple effect on the economy.
Earlier this month, Costco said it had reached a deal to buy rival discount retailer Loblaw.
Wal-Mart, the country’s largest retailer, has been trying to expand its online presence with deals and promotions.
Australian retail sector faces challenge from online retailers Costco, Costco Wholesale, Loblaw, and Zara are the largest retailers in Australia.
The group’s annual report shows it expects to grow its total revenues to $7.5 billion this year.
The retailer has faced criticism in recent years over its pricing and service.
In September, a Senate inquiry found that Costco had a pattern of undercharging customers, including by charging them more for items that were actually being offered at a lower price than they were advertised.
Its chief executive, Doug McMillon, was forced to resign in 2014 after a number of scandals.
As well as closing stores in Australia, Costco has closed its Australian stores in New Zealand, Singapore, Hong Kong, Thailand, Taiwan, Thailand and Thailand.
This article has been updated with Costco’s statement.
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