Metro says it has reached a tentative agreement that would end a historic six-month strike at its produce warehouse in Laval, Quebec — a work stoppage that cost the company $64.2 million in its fiscal third quarter alone.

The union representing the workers, the United Grocery Workers Union Metro-Richelieu, has endorsed the proposed contract. Its terms include a 22% salary increase over five-and-a-half years, with a 6% increase retroactive to last September and an additional 4% raise when workers return, according to a report in The Globe and Mail.

About 550 workers at the Laval distribution center and Metro's headquarters have been on strike since March 30. They are scheduled to vote on the proposed pact on Sept. 24. The agreement is unanimously supported by the union's bargaining committee, the Montreal-based retailer said.

The financial toll has been substantial. On its recent third-quarter earnings call with analysts, Metro estimated the strike cost the company approximately $64.2 million in lost profits and incremental direct costs during the quarter. The company's Q3 EBITDA fell 11.3% year over year after adjusting for separate, non-recurring restructuring charges.

"The labor disruption required significant attention and resources from our teams," said Eric LaFlèche, president and CEO of Metro. He noted the disruption affected both the Laval facility and another facility in Toronto that supported some of the company's stores in Quebec.

Despite the strain of running a contingency plan for produce distribution, LaFlèche said the company's stores remained "generally well stocked and in good condition." The Laval facility supplies more than 350 supermarkets in Quebec.

The pain is not over yet. The strike is also expected to affect Metro's fourth-quarter results, which end Sept. 27, according to the Globe and Mail report, citing a research note from analyst Irene Nattel of RBC Capital Markets. She said efforts to unwind the contingency plans and restore normal distribution operations could continue into the next fiscal year.

The road to a deal was long. Metro began negotiating with the union last December and made its first contract offer in June. The union overwhelmingly rejected that proposal and returned with a counteroffer, which the company rejected, a union spokesman told Supermarket News at the time.

The strike now stands among the longest grocery work stoppages in recent North American history. It outlasted the 141-day Southern California grocery strike of 2003-2004, which remains the longest and largest on record in the U.S.

If workers ratify the agreement on Sept. 24, Metro can begin the costly process of unwinding its contingency distribution network — but as Nattel's analysis suggests, a return to normal operations may stretch well beyond the strike's official end.