One of Mason City’s largest employers is facing a walk-out. Some 96-percent of the workers at Holcim Cement Company have authorized union leaders to call for a strike if labor negotiations break down before their contract expires at midnight Wednesday night. PACE Union Local President Michael Dunn says talks are still underway on three major issues in an attempt to avoid a strike. Dunn says little progress is being made in the negotiations. Dunn says Holcim is trying to eliminate overtime payments for working over eight hours in a day and eliminate premium pay for employees working on a Sunday, there are issues regarding the healthcare coverage for retirees. Dunn says workers believe that Holcim needs to up the ante with the company’s retirement healthcare packages. Dunn says the elimination of overtime and premium pay would be a burden for Holcim employees. Holcim spokesman Tom Chizmadia says the company is making its best attempt to negotiate a new contract.Holcim’s Mason City plant manufactures seven types of cement and has been a part of the community for almost a century and employs about 170 people.