He said coastal shipping was a relatively low carbon emission transport mode.
He said Government estimates showed the new shipping services could remove about 35 million kilometres of truck travel from roads annually.
The Aotearoa Shipping Alliance said it would get a multi-million-dollar grant to support the shipping network development.
Ngāti Waewae, Te Rimu Trust, Tainui Kawhia Incorporation and Westland Minerals Sands Co (WMS) form the alliance.
Ngāti Waewae chair Francois Tumahai said the funding agreement, once signed, would bring transport and logistics links to regional communities.
Tumahai said the changes would help businesses ship bulk commodities around the country.
WMS spokesman Ray Mudgway said the shipping network would strengthen New Zealand's domestic and global supply chains.
He said bulk commodities for construction and infrastructure in Auckland and Wellington could now be sustainably shipped from the South Island's West Coast.
He said Westport would be ready within months, and upgrades in Greymouth, Te Araroa near Gisborne, Kawhia in Waikato and Jackson Bay on the West Coast would follow.
"By 2026, our alliance will have a coastal shipping system with five operational and interconnected domestic ports."
Transport Minister Michael Wood said New Zealand was now closer to a more resilient, competitive, and sustainable coastal shipping sector.
He said coastal shipping was a small but important part of the New Zealand freight system.
Wood said the shipping network could help secure New Zealand's recovery from Covid-19.
"As a lower emissions transport mode, investing in coastal shipping will also help us achieve our decarbonisation goals," Wood said.
Waka Kotahi worked with the NZ Shipping Federation, Port Company CEO Group, National Road Carriers, KiwiRail, and Te Manatū Waka/Ministry of Transport to choose four applicants for co-investment.
The four suppliers were Coastal Bulk Shipping Ltd, Move International Ltd, Swire Shipping NZ Ltd and Aotearoa Shipping Alliance.
Wood said each selected supplier would bring at least one additional coastal shipping vessel into service.
The minister said the shipping network would help reduce wear and tear on roads, and improve safety for road users.
He said the network would also create new work opportunities for mariners.