The union that represented Northwest mechanics backed down at Delta ( DAL), meaning the 6,700 mechanics at the combined carriers will not have labor representation. In a notice posted on its Web site, the Aircraft Mechanics Fraternal Association said it came up short in its drive to secure sufficient signatures on union authorization cards to call for an election. As a result, AMFA said, it filed with the National Mediation Board to end the effort, which "will clear the way for Delta to treat the combined work group equally." The NMB on Thursday revoked the union's certificate. Delta and Northwest merged in October. At Northwest, AMFA replaced the International Association of Machinists as the mechanics' representative after a bitter 1998 election. In 2006, AMFA staged a disastrous strike that caused nearly all of its Northwest members to lose their jobs. The number of union mechanics declined from 9,795 in 1998 to a few hundred. "The mechanics at Northwest haven't had union representation for years, even with AMFA," said IAM spokesman Joe Tiberi. "Now they've made it official." The IAM continues to represent ground service workers and airport agents at Northwest and will seek elections at Delta. Delta said Northwest mechanics "will come up to the Delta pay scales and applicable license, skill and line premiums, effective with the next pay period," while union dues collection will end immediately. It said the transition to Delta's medical, retirement, time off and disability benefits programs will begin in January 2010.