The largest private-sector strike by U.S. workers in three years came to an apparent end Sunday, with the grocery chain Stop & Shop announcing it had reached a tentative agreement with the United Food and Commercial Workers union.

The union said in a statement that the new contract includes pay increases and “preserves health care and retirement benefits” for members. Neither the chain nor the union released full details on the agreement.

More than 30,000 Stop & Shop workers went out on strike April 11, protesting the company’s proposal to increase workers’ share of health care costs and cut benefits for future hires, including phasing out time-and-a-half pay on Sundays. The strike affected 240 stores in Massachusetts, Rhode Island and Connecticut.

The work stoppage put a huge dent in Stop & Shop sales, causing some stores to shut down certain functions or close entirely. Workers maintained picket lines day and night, encouraging shoppers to buy groceries elsewhere during the dispute.

Stop & Shop said in a statement Sunday that all its employees would be back on the job Monday morning.

“Our associates’ top priority will be restocking our stores so we can return to taking care of our customers and communities and providing them with the service they deserve,” the company said. “We deeply appreciate the patience and understanding of our customers during this time.”

Pete Katsigianis, a Stop & Shop employee who’s worked for the company for 48 years, told HuffPost last week that he was striking because the company’s proposal would degrade the job.

“A serious problem the company has is attracting talent,” Katsigianis said. “With this contract here, it is making conditions a lot worse. We just don’t feel like it’s deserved. It’s a lot of work in a supermarket ― very hard work ― and we don’t feel this is necessary.”

The Boston Globe reported Friday that the strike had cut visits to Stop & Shop by 75 percent, squeezing the company in the runup to the busy Easter shopping week. Stop & Shop is owned by the Netherlands-based grocery conglomerate Ahold Delhaize, which also includes the Giant and Food Lion brands.

The union called the strike’s resolution “a powerful victory for the 31,000 hardworking men and women of Stop & Shop who courageously stood up to fight for what all New Englanders want ― good jobs, affordable health care, a better wage, and to be treated right by the company they made a success.”