Kermadec Property Fund's shareholders vote on Wednesday on a $7 million plan to internalise management and acquire the Augusta Funds Management business.
The Shareholders Association will vote against the proposal through undirected proxies, saying it is too costly and it is concerned about the related party nature of the deal.
Kermadec, which owns five commercial properties worth $100 million, is run by managing director Mark Francis and his brother Chris, an executive director.
The plan is to internalise Kermadec's management by buying the assets of its manager, Augusta Funds Management, costing up to $7 million - money it plans to borrow.
Augusta is owned by the Francis brothers, making them the main beneficiaries of the deal.
Kermadec chairman, Peter Wilson, has defended the proposal.
He said the parties are clearly related so the process must be conducted with great care, and an independent appraisal carried out.
"The independent appraisal notes that the deal is fully priced but is nonetheless fair and notes that the opportunities are indeed available to the company."
Kermadec has 900 shareholders including institutional investors who make up 20% of the capital. Mark and Chris Francis, who hold nearly 18% of the capital, will not vote on Wednesday.
