The fertiliser co-operative Ballance Agri-Nutrients is investigating the redevelopment of the country's only nitrogen fertiliser plant, to take it through the next 30 years.
The ammonia-urea plant at Kapuni, in Taranaki, has been converting natural gas to fertiliser since the late 1980s, supplying about a third of the agriculture sector's urea fertiliser needs.
The plant has been regularly upgraded, but Ballance's chief executive, Mark Wynne, said after a year-long feasibility study, it was moving to the next stage in assessing the long-term options for the plant.
"We have requested from three international contractors that they submit detailed proposals to us at the end of this calendar year, and from there we will have a much clearer picture of the true costings, production capacity, health and safety, environmental foot print, etcetera," he said
"So we're looking at a number of options. Do we upgrade it, do we renew it completely, do we do nothing? So to work through that, obviously we need good engineering studies and accurate costings."
Mr Wynne said if it stacked up, a redevelopment plan would go to the farmer shareholders for approval in the second half of next year.
The Kapuni plant employs 130 full time staff as well as contractors.