Kellogg workers ratify a revised contract after being on strike since October.

About 1,400 striking Kellogg workers have ratified a new contract, their union said Tuesday, ending a strike that began in early October and affected four of the company’s U.S. cereal plants.

“Our striking members at Kellogg’s ready-to-eat cereal production facilities courageously stood their ground and sacrificed so much in order to achieve a fair contract,” Anthony Shelton, the president of the workers’ union, the Bakery, Confectionery, Tobacco Workers and Grain Millers International Union, said in a statement. “This agreement makes gains and does not include any concessions.”

Steve Cahillane, the company’s chairman and chief executive, said in a statement that he was pleased that the workers approved the deal. “We look forward to their return and continuing to produce our beloved cereal brands for our customers and consumers,” he added.

The strike had become especially contentious after workers rejected an agreement on a five-year contract between their union and the company in early December, and the company announced that it would move ahead with hiring permanent replacement workers.

President Biden waded into the dispute a few days later, saying in a statement that the plan to replace workers was “deeply troubling” and calling it “an existential attack on the union and its members’ jobs and livelihoods.”

The company and the union announced the second tentative agreement the next week, just before Senator Bernie Sanders, an independent from Vermont, was scheduled to hold a rally on behalf of workers in Battle Creek, Mich., home of the company’s headquarters and one of the cereal plants where workers had walked off the job.

The contract dispute revolved partly around the company’s two-tier compensation system, in which workers hired after 2015 typically received lower wages and less generous benefits than veteran workers. The company has said that the longer-tenured workers make more than $35 an hour on average, while the more recent workers average just under $22 per hour.

Veteran workers had complained that the two-tier system put downward pressure on their wages and benefits because they could effectively be outvoted or replaced with newer, cheaper workers.

Under the agreement that workers rejected in early December, the company would have immediately granted veteran pay and benefit status to all workers with four or more years’ experience at Kellogg. It would have also granted veteran status to a number equal to 3 percent of a plant’s head count in each year of the contract.

The initial agreement would have given veteran workers a 3 percent wage increase in the first year and cost-of-living adjustments.

In the agreement that workers just approved, the proposal for converting newer workers to veteran status remained unchanged, but the company expanded cost-of-living wage adjustments to cover all employees in each year of the contract, according to a Kellogg spokeswoman.

Newer workers will see their wages immediately rise to just over $24 an hour and veteran workers will immediately receive a wage increase of $1.10 per hour.