The Cook Islands Chamber of Commerce says the end of the New Zealand-funded Pacific Business Mentoring programme is a big blow to the local community.
The Chamber President Mike Pynenburg says since 2010 around 150 businesses have been involved in some way with the programme.
Under the programme, teams of five mentors travel to various countries for a week on a six-monthly basis to meet with participating businesses.
Mr Pynenburg says he has been told the Pacific-wide programme wasn't cost-effective but he says it had a huge impact in the Cook Islands, with growth in small business ventures.
"We have a huge problem here with depopulation and the more we can encourage locals to get involved in their own businesses here, the better for us being able to retain people in the Cook Islands."
Mr Pynenburg says eight new clients signed up to the programme this month before the chamber was informed that it would cease by December.