Reef Shipping says it cannot be blamed for cuts to shipping services in the Cook Islands.
It has issued a statement defending the quality of its service to the Cooks, after the withdrawal of MV Forum Pacific.
MV Forum Pacific is owned by Reef but was being leased to Pacific Direct Line and Pacific Forum Line under a joint venture agreement.
Recently the vessel's charter expired and Reef did not renew it, but Reef says it has offered the company space on its new ship, Southern Reef.
The Cook Islands opposition leader, Wilkie Rasmussen, has raised concerns about a monopoly shipping service.
He says previously when Reef has enjoyed a monopoly it has forced the closure of some small businesses whose cargo had a lower priority than some of Reef's bigger clients.
Meanwhile Reef says its new ship will increase capacity, and, with more speed and power, consolidate service frequency and schedule integrity.
Reef's John Gresson says it should deliver higher levels of service to all importers and consumers.