The National Mediation Board said that passenger service agents at American Airlines voted against unionizing after an election that concluded yesterday, Reuters reported. Of the 5,954 workers who cast a vote, 3,052 voted for no union, compared with 2,891 who voted in favor of the Communications Workers of America, according to results from the National Mediation Board, which conducted the election from Dec. 4 to Jan. 15. There were 7,792 people eligible to vote, a spokeswoman for the U.S. agency said. The worker group includes airport agents and reservations representatives. They are the only employee group at American not unionized.