Both companies operate salmon farms in the hydro canals in the Mackenzie district. Mount Cook Alpine Salmon (MCAS) produces just over 1000 tonnes a year and Aoraki just under 600 tonnes.
The acquisition was a ''logical step'' in the growth of the business. The majority of MCAS production went to high-end overseas customers, while Aoraki's production, particularly its smoked salmon products, was highly regarded in the domestic market, MCAS chief executive David Cole said.
The combined company would employ more than 150 staff across its two hatcheries, salmon farm operations, Timaru processing plant and the Christchurch-based Aoraki smokehouse business.
MCAS opened a $6million processing factory at Washdyke in 2013, allowing the company to transfer the processing of its salmon from Christchurch.
Over time, there would be some restructuring as the combined operations were integrated but it was ''business as usual'' at the moment, Mr Cole said in a statement.
''The goal is to have a sustainable, successful business in the central South Island, an outcome that we're confident will bring positive change and opportunities,'' he said.
MCAS chairman Jim Bolger said scale was needed to meet the demand from an expanding international customer base and it made ''good commercial sense'' to bring together the two major producers.
As minister of fisheries, Mr Bolger had licensed salmon farming in New Zealand. He was also prime minister when the government granted the first leases to farm salmon in the hydro canals in 1991, through the Electricity Corporation of New Zealand Ltd (ECNZ), now Meridian Energy.
