Aquaculture company New Zealand King Salmon is planning to double production to 15,000 tonnes of salmon a year by 2015.
The company said it planned to apply to the Environmental Protection Authority for planning permission to expand its operations and if successful could double production and sales in three to five years.
The company, which has $115 million of annual sales and employs about 440 people, said doubling sales was likely to create about 70 jobs, but it would need to find environmentally sustainable water space for at least eight new farms to meet market demand.
New Zealand King Salmon has a head office in Nelson and farming operations in Marlborough, and under the proposal would seek to increase its five surface hectares for salmon by another 10 surface hectares.
Chief executive Grant Rosewarne said the authority would require the company to prepare comprehensive evidence.
"Few agricultural industries have the ability to create such significant export income from such a small amount of space, with a low, localised environmental impact," Rosewarne said.
"It's well known among Marlborough locals that we have been identifying sustainable sites to raise premium salmon in areas acceptable to other users. We have invested millions of dollars and been highly successful in developing lucrative specialty markets overseas, which is great for us and great for the country."
King salmon species require cool temperatures, deep water and good tidal flows, meaning suitable new sites need detailed research.
A scientific team was studying the company's sites and improving understanding of the Sounds, Rosewarne said. "We are consulting with a number of people in the community. Everyone will be able to submit and call evidence in the Environmental Protection Authority process."
The authority process would take about 15 months to determine if, where and how new salmon farming could be undertaken in the Marlborough Sounds, the company said.
The aquaculture sector is worth about $380 million, with a target to grow to $1 billion of annual revenue by 2025.