Retailers added 465,500 seasonal workers in November, the most ever added during what is typically the busiest hiring month of the holiday hiring season, according to an analysis of data from the U.S. Bureau of Labor Statistics by outplacement firm Challenger, Gray & Christmas Inc. The previous record of 465,400 was set in 2007. November job gains were up 21 percent from the 383,700 seasonal workers hired by retailers a year ago, Challenger said. October job gains in the retail sector were adjusted upward to 145,200 from an originally reported figure of 130,100.