Tourism Holdings plans to lay off 63 staff at its campervan and motorhome assembly plant in Hamilton.
The cuts were announced when the company, which runs rental brands Maui and Britz, revealed plans to merge its manufacturing business with Kea Manufacturing in a joint venture.
Tourism Holdings will close its motorhome assembly business in Hamilton, which employs 127 people.
The joint venture will instead operate its main manufacturing plant in Auckland, while retaining a specialist bodywork business in Hamilton.
The union representing 29 of the 63 losing their jobs says there will be limited employment opportunities.
An Engineering Printing and Manufacturing Union spokesperson, Louisa Jones, says while most will be laid off, some staff might be able to continue working in the company's Auckland and Australian plants.
Ms Jones says the news came as total shock to many employees.