Aramark Corp. and a union representing food-service workers at Boston’s Hynes and South Boston convention centers have reached a tentative contract agreement after more than a year of talks. The deal provides higher wages and additional pension and health-care benefits for some 300 workers.

Contract negotiations, which started in September 2007, weathered a three-day strike this past June and the filing of an unfair labor practice complaint against Aramark by the National Labor Relations Board. The Massachusetts Convention Center Authority, which had threatended to terminate Aramark’s $27-million-a-year concessions contract over the dispute has now extended the deal through May 2010.