He said they were all New Zealand companies and each had provided written registrations of interest in buying the entire Holcim portfolio in Buller.
Holcim preferred to conclude as few transactions as possible, he said.
Holcim closed its Cape Foulwind cement works in June after 58 years of operation in Buller.
The assets for sale include the cement works site, a quarry, water treatment plant, 11 houses, the Westport packing plant site and silos on the Westport wharf.
The Cape Foulwind site, associated facilities and buffer land comprise over 500 hectares of land, including 200ha of farmland.
Most of the land is 14km east of Westport.
Mr Harding said the sale process had taken longer than expected because Holcim wanted a deal that was both good for the company and the West Coast.
"If it was just about who could do this fastest, at the highest price, we would have sold it. But we all understand it's far more important for the region than that.
"Holcim have been caretakers of the land and they are incredibly focused on making sure that the sale is handled correctly and ends up in the right hands... it's got to benefit the region, it has to. And the sum of the parts means that it can." He was hopeful of a conditional sale before Christmas.
Westport had plenty to attract prospective buyers, he said.
"It's got an airport. It's got great hunting. It's got great fishing. It's got a supermarket. It's got infrastructure. It's got a swimming pool. It's got everything there. It's got cheap housing. We just need to shine a light on the place." The scenery was stunning and Buller had more wealth than many realised, he said.
"We are just so conscious of making sure this [asset sale] is a springboard for the region rather than an international corporate just showing up and getting out." Holcim had had the Cape Foulwind site since 1953.
"They don't need $100 million for it... To replicate what Holcim owns there, and what they have today, would cost them $550 million." He declined to say what the assets might sell for, but said it would be "nowhere near" $550m.
"The responsibility of the sale is not so much about the highest price, it's about getting it into the right hands. And all the people we wanted to raise their hands, have... The interested parties that we have would certainly be of benefit to the area." Cape Foulwind offered views over the sea, a quarry, arable land, a proposed bike trail, and was near Tauranga Bay, he said.
"I think ultimately, in the end, parts of it need to be held in the tourism arena because they're spectacular." The cement works would be decommissioned and demolished, either by Holcim or the new buyer, he said.
Some administration buildings would remain.
Buller Mayor Garry Howard has been investigating the possibility of two of the Holcim silos on the Westport wharf - which council owns - being converted to apartments or a hotel.
Asked whether Holcim might gift the silos or any other assets to the Buller District Council, Mr Harding said: "Everything's on the table. Obviously this is a commercial decision. However, there's flexibility around it to make sure they [assets] get into the right hands." He said there was no truth to a local rumour that Talley's Fisheries was a prospective buyer. "They got all the information but they have declined to move forward at this stage." Holcim closed its Westport works, with the loss of over 100 jobs, in favour of importing cement from Japan. The company spent more than $100m building new import terminals at Auckland and Timaru.
- Westport News
