MADISON — Hydropower assets at the former Madison Paper Industries site have been sold to a New Jersey hydroelectric power producer, marking the final step in the sale of the paper mill and opening the door for future plans at the property.

Madison Paper, a former partnership of UPM and Northern SC Paper Corp., a subsidiary of The New York Times Co., has signed an agreement to sell its hydropower facilities to Eagle Creek Renewable Energy LLC, which is based in Morristown, New Jersey, Madison Paper said Tuesday in an emailed statement.

The paper mill, which put about 215 people out of work when it closed in May, was sold in December to a buyer with plans to put the property back into use as an industrial site. But that has been on hold pending the sale of the hydroelectric assets. The purchase of the mill site – for an undisclosed price – included the real estate of the main paper mill and all mill equipment.

Tuesday’s announced transaction on the hydropower assets – two hydroelectric dams and power plants – is still subject to third-party approvals. The parties have agreed not to disclose the purchase price.

“Eagle Creek is a well-known and experienced operator of hydroelectric power facilities in North America,” Ruud van den Berg, senior vice president for magazines, merchants and office at UPM Paper in Helsinki, Finland, said in an emailed statement. “The company focuses on CO2-friendly power production and has a long-term, focused business strategy in this sector. As an integral part of an energy company, the hydropower facilities can be operated and developed in an optimal way.”

In March, UPM also sold its hydropower facilities in Steyrermuehl, Austria, and in Schongau and Ettringen, Germany, according to emails from the company.

The overall mill property was sold to a “joint venture” of New Mill Capital Holdings, of New York; Perry Videx, of Hainesport, New Jersey; and Infinity Asset Solutions, of Toronto. Gregory Schain, principal of New Mill Capital Holdings, said Tuesday that the pending sale of the hydropower assets helps turn the page and open a new era for central Maine.

“I think it’s great,” he said. “It finally closes one chapter and hopefully opens another for property in the area. Now that UPM is mostly out of the picture, hopefully the two parties – us and Eagle Creek – can work together to bring some economic life back to the site.”

Schain said there are businesses interested in the former Madison Paper site, but he would not identify them. The town has courted Poland Spring about possibly occupying the site.

Schain said discussions with future buyers or tenants have been on hold pending the sale of the hydro assets. Now, he said, those discussions can advance.

Russ Drechsel, president and CEO of Madison Paper, was philosophical Tuesday about the approaching final curtain in the long history of the paper mill.

“It’s been over a year ago, 13 months ago, that we announced the closure of the paper machines,” Drechsel said. “So it’s another chapter and it’s near the end of the book. It will be good to finish everything up”

Bud Cherry, CEO of Eagle Creek Renewable Energy, said in the emailed statement Tuesday that the company looks forward to doing business in Maine.

“Eagle Creek is very pleased to broaden our footprint in central Maine,” Cherry said. “The Madison Paper Industries hydroelectric portfolio represents an excellent opportunity to build out our operations in the region through the acquisition of a well-maintained, high-quality set of hydro facilities.” 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.