GARDINER – The Gardiner Paperboard mill shut its doors Thursday, putting 40 people out of work and idling the 125-year-old mill.

Fred G. von Zuben, president of The Newark Group, the mill’s parent company, said the mill has been operating at reduced capacity for several months.

“This is economically feasible in the short term, but totally uneconomical in the longer term,” von Zuben said in a prepared statement. “At this time, we see no reason to believe that the general economic conditions or internal needs of the company will change dramatically, and we are forced to discontinue operation of the mill.”

Gardiner Mayor Brian Rines said the Gardiner Paperboard mill has been at the same location on Water Street since 1876. He said the folding paper grocery bag was created at that location.

Rines said he remembers when there were three mills in the city when he was growing up.

“It’s incredibly sad to see them gone. It’s really an end of an era,” he said. “We were the quintessential New England mill town.”

The mill manufactured recycled paperboard, which is used in numerous products including books, toys, cereal cartons, rigid boxes, mailing tubes, furniture and other products.

The Newark Group, which is headquartered in Cranford, N.J., has more than a dozen other paperboard mills nationally.

The Gardiner Paperboard mill and equipment was assessed at more than $1.7 million, meaning the city stands to lose $21,000 in annual property taxes, said Gardiner City Manager Jeffrey Kobrock.

The Newark Group also owns Newark Papertube in South Gardiner, which employs about another 20 workers. The company said that plant will stay open.