MADISON — The new owners of the shuttered Madison Paper Co. mill will hold a three-day online sale of more than 3,000 pieces of paper mill equipment next month.

The 550,000-square-foot facility closed last May after 35 years on the banks of the Kennebec River, leaving 214 mill workers without jobs.

New Mill Capital Holdings of New York City, in partnership with Perry Videx, of Hainesport, New Jersey, and Infinity Asset Solutions, of Toronto, acquired the mill property in December.

The 3,000-item sale, to be held June 13-15, will feature items such as debarking equipment, log grinders, vacuum pumps and other industrial equipment, the company said Tuesday in a written statement. The Valmet paper machine, which was upgraded in 2012, is also for sale via private negotiation.

The auction is to be conducted exclusively online at bidspotter.com, an industrial auction site.

“While the Valmet paper machine itself is being sold via private negotiation, the balance of the plant production and support equipment will be sold at the auction,” Eric Weiler, principal at New Mill Capital Holdings, said in the statement. “There is a large volume of machinery available, ranging from specific paper production assets to general plant support equipment.”

Prospective buyers are invited to schedule an inspection of the equipment at any time by appointment or by attending open inspections June 8, 9 and 12 at the mill on Main Street in Madison.

Weiler said later Tuesday in an email that the pending sale is “tracking very well,” particularly from the number of buyers that have already registered to bid.

“With the sale three weeks away, I’m very happy with the interest so far,” he said. “In today’s auction environment, most buyers see the sale, plan to bid, but don’t register until much closer to the sale date. We’re also just getting into the heaviest advertising push.”

The company intends to sell what it can and find tenants or buyers for the vacant buildings.

The real estate is currently available as well.

The mill produced supercalendered paper used for magazine publishing and has been in Madison since 1978. It was producing about 195,000 tons of paper annually at the time the closure was announced.