KiwiRail hopes to complete a sale of the Hillside workshops in Dunedin in about a fortnight.
The company says interested buyers are going through due diligence checks and a sale should be concluded in about two weeks.
The Rail & Maritime Transport Union considers the chances of selling the workshops are good.
Sources confirm buyers are mainly interested in a metal-casting foundry at the site. Other parts such as train building may close.
KiwiRail's business plan last week showed the company intends to close Hillside if it does not sell.