Locke Insulators Inc. announced Monday it will close its Port Covington manufacturing plant and lay off 108 employees.

The manufacturing plant, located on a 26-acre lot at 2525 Insulator Drive, will wind down operations over the next few months in response to dwindling demand for its electric utility insulators, the company said in a statement.

Locke Insulators makes porcelain station post insulators used by electric utilities to control the flow of electric current through electrical wires. Demand for Locke Insulators' products has declined in recent years, as utilities began using less expensive imported insulators, the company said.

"We remain committed to supporting Locke's employees throughout this difficult transition," said Don McKenzie, Locke Insulators' president. "We will consider the assistance to be provided to employees losing their jobs after the union representing Locke's production employees has had an opportunity to review the shutdown of the manufacturing facility."

The company employs 84 production-related employees who are represented by the United Electrical, Radio and Machine Workers of America.

James Cook, president of the union's local chapter, said the union was caught off guard by news of the closure.

"This came out of nowhere," Cook said.

Cook said the union last fall finalized a three-year contract that runs through September 2019.

Lock Insulators also employs 24 salaried workers.

The company was founded in 1893 and moved its headquarters to Baltimore in 1922, according to its website.

Locke Insulators and Baltimore-based affiliate NGK-Locke are part of NGK Insulators in Japan. NGK-Locke handles sales and marketing for its parent company.

Both Locke Insulators and NGK-Locke have operations in the Insulator Drive building, which is owned by Locke Insulators, according to property records.

The property is within the Port Covington area where Sagamore Development, Under Armour CEO Kevin Plank's private real estate firm, is planning a $5.5 billion redevelopment.

A spokesman for Sagamore declined to comment Monday on whether the firm would be interested in buying the property if it is put on the market.

Ray Weiss, a spokesman for Locke Insulators, said the company had not decided what to do with the building. NGK-Locke has about a dozen employees based in the building who will remain there for the immediate future, he said.