Two union leaders said on Tuesday that negotiations between Kellogg and the union representing its U.S. breakfast cereal plant workers had broken down again, prolonging a strike that began in October.

After negotiations over pay and benefits stalled due to differences between the company and about 1,400 union members at Kellogg's cereal plants, the workers went on strike on Oct. 5. Their contracts had expired the day before, and negotiations over pay and benefits had stalled due to differences between the company and about 1,400 union members at Kellogg's cereal plants.

One of the Original Plant-Based Food Companies| Kellogg's

Kellogg proposed a two-tier employment system, according to union members, that did not provide a path for temporary workers, who make up approximately 30% of the company's workforce, to become permanent employees with better benefits and salaries.

The union stated in a statement on Tuesday that it was still working on concerns related to the two-tier structure and volunteered to meet with Kellogg the week of Dec. 6.

A request for comment from the corporation was not immediately returned.

Kellogg would have to pay temporary workers in lieu of the strikers and import cereals to secure supply as a result of the latest setback in negotiations, reducing the company's profit margin at a time when corporate America is already battling with rising costs.

A fresh offer was rejected by the union earlier this month.