BRADLEY, Ill. — Hundreds of workers at a medical plant in Kankakee County are walking off the job.

The contract for union workers at CSL Behring in Bradley, Illinois expired Wednesday night. A large number of employees are rallying outside the main entrance to the facility Thursday.

They are calling for a new three-year deal — negotiating sessions were held Monday and Tuesday.

In a statement, CSL Behring said it offered an excellent contract proposal that includes an 11% raise over three years, plus other benefits on holidays and healthcare.

But unlike many strikes, the two sides are not necessarily at odds over money and benefits, instead it’s about outsourced work to non union workers.

CSL Behring is Kankakee County’s largest manufaturing facility. There are more than 1500 workers at the bio pharmaceutical company, more than 700 are members of the union.

The two sides have been negotiating for a while. The company said it is ready to resume negotiations, however union leadership said they have not heard from the company as of yet.