Employees at a Shaw's Supermarket distribution centre in Maine ratified a new contract over the weekend, following the example set by staff at other stores in Massachusetts and in Rhode Island and thus avoiding a strike.

The Maine contract covering 350 workers, and the larger one covering about 5,600 employees in Massachusetts and Rhode Island, expired last weekend, and employees voted overwhelmingly last Sunday to authorise a strike.

The union agreed to extend talks on both contracts for another five days, then struck the deal with Shaw's late Thursday night, with the help of a federal mediator.

Negotiators had been meeting since June to try to resolve differences over issues including healthcare costs, wages, work rules and pension benefits.

Workers at other Shaw's stores in Massachusetts, Maine, New Hampshire and Vermont are non-unionised and unaffected by the contract. Unionised Shaw's employees in Connecticut are covered by a different local., reported AP.

Shaw's is owned by Boise, Idaho-based Albertsons Inc., one of the nation's largest food and drug retailers.