URBANA, Ill. (WCIA) — An Urbana plant that has been in operation for 50 years is closing its doors by the end of the year.

Mayor Diane Marlin confirmed that that she received an email Friday afternoon from Dart Container Corporation, the parent company of Solo Cups, to inform her of the closure of their Urbana plant. Company officials said the closure is happening due to declining production volume.

135 jobs will be lost as a result of the closure. The employees were informed of the decision in the morning.

“Our priority during this time is the employees whose positions will be discontinued, and their families,” officials said. “Our goal is to help them move forward and treat them with the dignity and respect our company values and culture demand and they deserve. Dart will provide offers of severance and outplacement assistance to the approximately 135 employees who work at the Urbana plant.”

Marlin said that the Champaign County Economic Development Corporation will be working closely with Urbana’s Economic Development staff on this issue.

The plant, located at East Main Street and South Lierman Avenue, makes several items including Solo’s iconic red cups. Solo operated the factory until 2012, when it was bought by Dart.