PCR manufactures a variety of pesticide baits, including the pellets containing 1080.
The council invested $1.9 million in the venture in 2013, paying $1.3 million for the property and building, and $490,000 for a 49 per cent share in the business.
The council kept the investment quiet for about a year, and when it was uncovered by the Greymouth Star it sparked a petition and angry protests by anti-1080 demonstrators.
Announcing the sale today, council chairman Alan Birchfield said the council was selling mainly because the investment had failed to generate the expected profits.
"We weren't getting a decent return, but also the company's being prosecuted over a safety incident and though it didn't happen at our [Rolleston] site, there's some risk of liability, so we're pulling out."
WorkSafe NZ has laid charges against PCR after a worker was poisoned by an unnamed chemical at its Bromley warehouse, and hospitalised for two weeks. He later made a full recovery and the case is yet to go to court.
Birchfield said the council had sold its share for a dollar to majority shareholder Matthew O'Brien, but would be paid out about $390,000 owing to the council from the joint venture's current account.
"The council hasn't had the profits it hoped for from the joint venture, but it hasn't cost the ratepayers a cent overall," Birchfield said.
The council would keep ownership of the property in the Rolleston Izone industrial park, and PCR would remain as tenant, paying the council $96,000 a year in rent, with a rent review due in January.
"That is a sound investment. We've spent a bit on the building, but properties there are in high demand and will continue to increase in value; ours has gained about $400,000 in CV, which is a lot more than what we spent on the improvements."
With the council's exit from PCR, chief executive and majority shareholder Matthew O'Brien becomes the sole owner of the company.
He has so far declined to comment on the deal.