Whanganui's Trafalgar Square shopping mall is up for sale and is expected to fetch more than $20 million.
A spokesman for the agency representing the owners said smaller malls were in high demand as there was a shortage of quality retail investments and a surplus of investor cash.
Smaller malls also allowed investors a less expensive door into retailing.
Trafalgar Square has several advantages, including being well established and providing a diverse income stream, the spokesman said.
The mall opened in 1989 at a cost of $19.1m and was refurbished in 2014.