KiwiRail is expected to announce in the next few weeks that it plans to buy more than 2000 railway wagons from China.
A deal was signed last December to buy Chinese 300 wagons, worth $29 million. The new deal will amount to well over $100-million.
As well, a small number of wagons have been built in the company's workshops.
KiwiRail says its 4000 wagons are all more than 30 years old and need to be replaced.
Chief executive Jim Quinn says it needs to buy between 300 and 500 more each year for the next few years.
He says he does not think the company's own workshops, in Dunedin and Lower Hutt, are up to the task of building wagons competitively.