The Trans-Tasman Resources (TTR) board will appeal against the Environmental Protection Authority's (EPA) decision to decline its marine consents for mining iron sands off the South Taranaki coast.
Last month the authority scuttled plans by TTR to mine 50 million tonnes of sediment a year, across 65.76 square kilometres of the South Taranaki Bight.
It was turned down primarily because of environmental concerns.
The precedent-setting case was the first to be heard under new Exclusive Economic Zone laws.
TTR has until July 9 to to appeal but only on a question of law.
Chief executive Tim Crossley said the company had spent more than $60 million trying to get the green light for the mining work, and was confident there were strong grounds for a successful appeal.
"Because this will now be dealt with through a court process, TTR will not be commenting further and we are not yet in a position to disclose the basis of our appeal as these will be sent to the EPA and submitters in the first instance before being released by the EPA."
Crossley expects the court to deal with the matter within six months, although the timing of the appeal is in the hands of the EPA.
Kiwis Against Seabed Mining chairman Phil McCabe expected TTR to challenge the decision but thought it would be fruitless.
"The [EPA's] decision-making committee gave a comprehensive decision covering a lot of aspects of the application that weren't up to scratch. I don't see what could come from an appeal."
In the Environmental Protection Authority's 248-page decision, the committee said the main reasons for knocking the plans back "were the uncertainties in the scope and significance of the potential adverse environmental effects and those on existing interests, such as the fishing interests and iwi".
In light of that, the EEZ Act required the EPA to favour caution and environmental protection.
Crossley said TTR's objective was to develop an iron sands extraction project that achieved substantial economic development while protecting the environment.
He said the project would have significant economic benefits, creating 250 direct and 170 indirect jobs. It would grow gross domestic product in the Taranaki regional economy by 3 per cent, or $240m a year, and the country's GDP by $302m a year. The project would earn New Zealand $50m a year in tax and royalties.
TTR had successfully applied for a mining consent earlier this year.
- The Dominion Post