Also, instead of implementing the management offer that supermarket workers had all but unanimously rejected in late June, Acme said it would continue to honor the old contract, which expired today, said Wendell Young IV, president of United Food and Commercial Workers Local 1776.

The bargaining session broke at 7 a.m., and Young said both sides agreed to continue talking into next week. Workers reported to their jobs today, despite earlier threats of a potential walkout at Acme's 41 stores in Philadelphia, Bucks, Delaware, Montgomery and Chester Counties.

"The parties will reconvene on Monday, and the company has agreed not to implement any portion of our last, best and final offer through Monday, July 13," Acme said in a statement this morning.

"All ACME stores remain open for business and our associates are ready to serve customers throughout the Greater Philadelphia area," the company said.

Young said both sides now were taking things "one day at a time."

His muted tone this morning was a departure from a more accusatory news conference UFCW held yesterday during which Young accused Acme of refusing to compromise.

In that announcement in front of an Acme in King of Prussia yesterday afternoon, Young urged the local's 4,500 area supermarket employees to report to work today and stay on the job until a membership meeting Wednesday at the Spectrum.

At that event, Young said that he hoped to hash out a settlement at the bargaining table. But he said a work stoppage was still on the table, depending on what happened before Wednesday.

He called Acme's take-it-or-leave-it contract offer "unacceptable" and said it would be "devastating" to members, though he did not elaborate on what, if any, progress had been made in negotiations with Acme this week under supervision of a federal mediator.

"We're going to show up and serve our customers," Young said, as a crowd of supporters cheered and chanted that they wanted to work. "What happens after that might be a different story."

Before this week, Acme officials said they had the right to unilaterally implement the new contract starting today. About 95 percent of UFCW workers rejected the offer at a vote at the Spectrum in late June.

"We believe the union should ratify this fair final offer so we can secure the future of our associates and Acme Markets," the company said in a statement issued after Young's 4:30 p.m. news conference Thursday.

Previously, Young had said union members would stay home from work if Acme implemented the new terms. His message yesterday was that the union would let the situation unfold for a few more days.

While saying he was willing to bargain, Young accused Acme, based in Malvern, and its corporate parent, Supervalu Inc. of Minnesota, of trying to rectify bad business decisions by slashing the benefits of workers.

Acme's proposed four-year contract would eliminate health-care benefits for up to 2,000 workers, he said, even though the company has cast the offer in more charitable terms.

"Lack of reinvestment, poor management have added up to this company trying to make our workers the scapegoat," Young said. Since May, Supervalu has replaced its chief executive officer, said it would replace its chief operating officer, and announced a corporate realignment.

Young said there would be no strike vote Wednesday. Acme could consider a walkout tantamount to a strike and attempt to make that case legally to the National Labor Relations Board.

Union lawyer Stuart Davidson said Acme was guilty of acting in bad faith by walking away from negotiations. He said it seemed like a planned tactic, which would strengthen the union's legal case.

The company has said that after more than 18 months of talks, it had the right to issue its last, best offer.

Contact staff writer Maria Panaritis at 215-854-2431 or mpanaritis@phillynews.com.