Unilever is proposing the closure of its laundry powder manufacturing site in Petone, with the possible loss of 58 jobs.
The Petone plant makes Surf, Drive and Persil brands for the Australasian market.
Under the proposal, production would continue at Petone for a period of up to 18 months, after which there would be a decommissioning period of between three and six months.
If the proposal goes ahead, the site could close by the end of 2015.
The production of laundry powders for the Australasian market would move to Australia.
"Unilever has a proud history of manufacturing in Petone and we recognise how significant this proposal is for our employees and the local community.
"We are faced with a market where consumers are increasingly turning to liquid laundry detergent formats, rather than powders, which has resulted in a reduction in volumes at Petone.
"We have done what we can to address this changing market, however regrettably we are now at a stage where closing the Petone factory appears to be the only viable option available to us," chairman and chief executive officer of Unilever Australia and New Zealand Clive Stiff said in a statement.
Unilever axed 33 workers from its Petone plant in 2009, moving from a seven to five day a week operation.
It has a long history in the Petone area, starting in 1919 with the production of Sunlight and Lifebuoy soap, as well as Rinso soap powder.
- Fairfax Media