Chatham Rock Phosphate wants to raise up to $10 million to get the company to the point where it can start mining.
Its resource is rock phosphate on the seabed of the Chatham Rise, about 450 kilometres off the coast of New Zealand.
Chief executive Chris Castle said company needs two more consents before it can begin mining.
He said he expects the mining licence will be granted very soon and the company also needs a marine consent which will be a longer process with an outcome expected in January 2014.
The company is forecasting that after production begins in mid-2015, it expects its annual operating profit for the 15 years of the life of the mine will be between $62 - $100 million.