Nearly 600 workers at a Siemens Westinghouse Power Corp. plant in south Charlotte will decide this month whether to unionize. The vote set for April 16 at the turbine plant follows two rounds of layoffs that have chopped about 400 jobs since September. The National Labor Relations Board, which typically monitors about 75 union votes a year in the Carolinas, says most votes involve fewer workers. The Siemens vote comes as union membership in the private sector continues to wane, in a state that has one of the lowest percentages of unionized workers.

Employees at the plant approached the United Steelworkers of America for help in organizing a union, said Mike Yoffee, organizing director for the Steelworkers in Pittsburgh.