By HILLEL ITALIE
AP National Writer
NEW YORK (AP) — Some 250 copy editors, marketing assistants and other employees at HarperCollins Publishers went on strike Thursday, with the two sides differing over wages and benefits, diversity policy and union protection. It was a rare work stoppage in the book publishing industry, where HarperCollins is the only company among the so-called “Big Five” to have a labor union. The HarperCollins union, Local 2110 of the United Auto Workers, struck for one day last summer and this time plans to stay out indefinitely until an agreement is reached. Employees had been working without a contract since April.