Four new salmon farms have been approved for the Marlborough Sounds.
New Zealand King Salmon wanted to create nine more farms, but the Environmental Protection Authority has granted it permission for four new sites.
The application process has cost the Nelson-based firm $10 million - more than five times its original estimate - and the company says it has taken a big financial hit.
New Zealand King Salmon said the new farms would create 200 jobs for the region and double the company's production - particularly in the lucrative export market - but it is unfair that it had to spend that amount of money to get just four farms.
The Government has long said it wants to turn the aquaculture industry into a billion dollar business by 2020.
New Zealand King Salmon chief executive Grant Rosewarne says for that reason, it should not have had to fight in court to expand and it should be for the Government to allocate space and call for tenders.
Mr Rosewarne told Radio New Zealand's Checkpoint programme on Thursday he believed his company should not have to be pitted against environmental groups or people that own baches in the Marlborough Sounds.
The decision has been met with disappointment by campaign group Sustain our Sounds, which believes the new farms will have a detrimental effect on the environment and tourism in the Marlborough Sounds.
The group is considering whether to appeal against the decision.