TEWKSBURY, Mass. — Arthur T. Demoulas has reclaimed ownership of Market Basket.

Arthur T. Demoulas has reclaimed ownership of Market Basket.

The owners of the New England supermarket chain agreed to sell him the 50.5% stake of his cousin Arthur S. Demoulas for $1.5 billion. The deal ended a 40-day ownership fight following Arthur T. Demoulas’ acrimonious ouster in June.

The returning owner said he was coming back with day-to-day operational authority. "The shareholders and the company would like to thank Market Basket customers and partners for their strong support through the years," he said last month. "Our shared goal is to return Market Basket to the supermarket that its customers have come to rely on for service, quality and best prices."

He added that all employees, many of whom had been boycotting the chain under the new management, were invited to return to work "to restore the company back to normal operations."

As a result of the boycott, store shelves emptied and customers stayed away. The company began losing millions of dollars a week, and analysts questioned whether it could be saved.

Many shoppers joined rallies in support of Arthur T., who has been in a long-running feud with Arthur S. over the direction of the business, which operates 71 stores in Massachusetts, New Hampshire and Maine.