The Northern Indiana Public Service Company has reached an agreement with the United Steelworkers, ending a month-long lockout.

NIPSCO says clerical employees will return to work next Tuesday following Friday’s announcement. Negotiations began in January ahead of the March 31 contract expiration, but talks failed to produce a deal, leading to a lockout that started April 2.

Earlier, physical bargaining unit employees returned to work after an April 24 agreement.

The lockout affected more than 1,600 workers across northern Indiana though service continued without interruption or safety incidents, according to the company. Officials say operations will now resume fully operations.