Air New Zealand expects its new planes, with greater capacity, will improve its cargo performance as well as drive growth overall.
One of the weak spots in Air New Zealand's otherwise very strong profit report last month was its cargo results.
The government-controlled airline's cargo sales fell nearly 5 percent to $287 million in the year ended June, small in the context of its $4.7 billion in overall sales.
Chief executive Christopher Luxon said the new planes would make a difference.
"As we bring in a 777-300 to replace a 747 that comes with 40 percent more cargo capacity in that aircraft, as we bring in a new Dreamliner to replace a 767 that comes with two and a half times more capacity in the belly of the aircraft that we can put high-value perishable, time sensitive exports from New Zealand into that aircraft."
Mr Luxon said as the company builds its passenger network its cargo capacity gets the benefit or works within that capacity constraint.
He said cargo is a relatively small proportion of Air New Zealand's total revenues.
Mr Luxon said the new improved aircraft can take more passengers as well as taking a fully belly of cargo which will provide exporters with greater certainty of service.