Ballance Agri-Nutrients says a fire at its urea manufacturing plant at Kapuni in Taranaki will force a shutdown for several days.
Seven fire crews and a company specialist crew took about an hour to extinguish the fire, which began just after 9.30am in the ammonia plant on Monday.
Site manager John Maxwell says the fire was contained in one area of the plant and there are no environmental issues.
He says staff at Kapuni regularly undertake safety and fire-fighting and were well equipped to deal with the incident.
Mr Maxwell says the company does not expect the loss of production to impact on the supply of urea during spring.