Supermarkets FreshChoice and SuperValue will stop selling cage eggs by 2025 – the same timeframe in which Countdown aims to phase them out by.
All three supermarkets are owned by Progressive Enterprises, which last March announced its goal for Countdown supermarkets to be cage-free by 2025.
"We are pleased to be working with our suppliers towards offering only cage-free eggs in the near future," said Kiri Hannifin, general manager of corporate affairs at Countdown.
Animal rights' campaigners SAFE said this was a "pivotal moment in history".
"Now all the major supermarkets have decided to go cage-egg-free, the market for such cruel products is decreasing to the point that the egg industry will be rethinking any decision to build new colony cages," SAFE's Mandy Carter said.
"This policy extension by Countdown's owner, Progressive, isn't just a step forward to free hens; it hammers a huge nail in the coffin of colony cages," she said.
The parent company of New World and Pak'nSave last year also committed to selling 100 per cent cage-free eggs by the end of 2027.
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