Union activists suffered a setback Wednesday when a majority of Delta Air Lines flight attendants rejected union representation. But labor activists predict that a union will represent attendants brought together under a Delta-Northwest Airlines merger.

For 79 years, Delta's attendants have worked outside of the organized labor movement, but 40 percent of them voted in recent weeks to join a union.

"Those supporters, combined with strong union support at Northwest, will clearly be enough for the flight attendants to win union representation after the merger with Northwest is finalized," Patricia Friend, president of the Association of Flight Attendants (AFA), said in a prepared statement.

Friend and other union supporters are using simple math to project that they will have enough votes to keep Northwest attendants under the union umbrella and to bring Delta employees into the fold.

The National Mediation Board reported that 5,306 of Delta's 13,382 flight attendants voted in favor of union representation. If a substantial majority of Northwest's 7,500 attendants join forces with the Delta attendants who now want a union, they would have enough votes to ensure that labor leaders negotiate a contract for them under the merged Delta.

In 2002, only 29 percent of Delta's attendants voted in favor of joining a union.

Mollie Reiley and Danny Campbell, former Northwest labor union officials who advised the Delta attendants, said that they expect the two attendant groups ultimately will be blended into an AFA unit. Reiley and Campbell were leaders of the organizing drive that brought the AFA to Northwest in 2006.

If the Delta and Northwest attendants forgo union representation, they would be "subject to whatever management deems is appropriate for cost efficiencies," Reiley said. She also noted how union support at Delta has grown since the last election.

Delta management waged an extensive campaign to encourage its attendants to reject the union.

"It was important to get the facts out there," Sandy Gordon, a Delta vice president of inflight services, said after the vote results were released. She said that AFA supporters had spread "a lot of misinformation" about the prospect that Delta would outsource jobs. Instead, she said that Delta has been hiring U.S. citizens with foreign language skills.

Campbell, who led the Northwest attendants when they were represented by the Teamsters, said that the outsourcing issue was legitimate, because when Northwest was in bankruptcy, management proposed shifting work to foreign attendants.

Delta CEO Richard Anderson, who frequently met with labor leaders when he was the top executive at Northwest, praised the Delta attendants for choosing to preserve Delta's work culture and management's direct relationship with its attendants.

"Delta continues to be the best advocate for its people, and our employees recognize the benefits of working together to enhance their careers," Anderson said.

But Kevin Griffin, president of the Northwest branch of AFA, said that Delta management had used "intimidation and coercion" to fend off the union.

Delta circulated a DVD to its attendants, which featured Delta executives and flight attendants talking about the positive aspects of their relationship. Gordon said attendants could watch the video "in the privacy of their own homes."

After the vote, Delta managers released a memo to attendants that said they had listened to employee input over the past year and "made more than 40 significant changes that benefit flight attendants and our operation."

Northwest attendants have engaged in considerable political infighting in recent years, as they broke with the Teamsters, created the independent Professional Flight Attendants Association and then joined the AFA, a large union affiliated with the AFL-CIO.

Now Griffin is trying to rally attendants from all of those camps to preserve union representation for his members.

If the Department of Justice approves the Delta-Northwest merger later this year, Griffin estimates the two attendant groups would vote on union representation in 2009.

John Budd, a human resources professor at the University of Minnesota, said Wednesday's election results put flight attendants at both airlines in a "holding pattern." The union issue likely will remain a major distraction at both carriers until the next election, he said.

Northwest's workforce is highly unionized. At Atlanta-based Delta, only the pilots and dispatchers are union members.

The ground workers, including customer service agents and equipment service employees, constitute the largest union group at Northwest. They are represented by the International Association of Machinists and Aerospace Workers (IAM).

Joe Tiberi, an IAM spokesman, said that his union has been conducting an organizing drive among Delta ground workers since late 2006.

"There's absolutely no doubt that Delta's plan is to remain largely nonunion if this merger takes place," Tiberi said. "If the merger occurs we want to make sure that not only Northwest members retain representation, but that the Delta workforce finally gets to enjoy the benefits of a union contract."

Liz Fedor • 612-673-7709