WASHINGTON — Airport screeners around the county have chosen the nation’s largest federal employee union to represent them in collective bargaining talks with the government, federal officials announced Thursday.

The American Federation of Government Employees won a close runoff vote to represent about 44,000 employees at the Transportation Security Administration in the largest union election for federal workers in history.

Federal officials tallying the votes say AFGE received 8,903 votes, or 51 percent, while National Treasury Employees Union got 8,447 votes, or 49 percent. The runoff was held after neither union received more than 50 percent of votes during the first election earlier this year.

The vote came after TSA head John Pistole agreed in February to grant screeners limited collective bargaining rights for the first time since the agency was formed a decade ago. The screeners who inspect bags and guide passengers through security had been among the few federal workers without union rights.

“We are obviously thrilled with the election results, but more importantly are delighted that the transportation security officers now will have the full union representation they rightly deserve,” said AFGE President John Gage.

Gage said his union would reach out to workers at airports across the country for input on contract negotiations and address the different needs of employees at small and large airports. AFGE represents about 625,000 workers in the federal government and the government of the District of Columbia.

Republicans have widely criticized the decision to grant collective bargaining rights for airport screeners, arguing the move would threaten the government’s ability to respond quickly during emergencies. The Bush administration refused repeated requests to grant union rights since the agency was created after the 9/11 terror attacks. But President Barack Obama promised to reverse that policy during his first campaign for the White House.

Pistole has said his decision won’t compromise security because it allows bargaining only on a narrow range of issues, such as work shifts, transfers, vacation time and awards.

It prohibits negotiating on security-related matters like deployment, job qualifications, testing or discipline, and does not change current regulations that already ban strikes or work slowdowns.

Democrats and union leaders point to thousands of other government security workers, such as border patrol agents and customs officers, who have had union representation for years with no problems.

“Transportation security officers join the ranks of firefighters, police and emergency responders, who have a say through collective bargaining to protect the public’s safety and make their jobs more efficient and productive,” said AFL-CIO President Richard Trumka.

Union officials are still fighting off efforts in Congress to override Pistole’s decision. Earlier this month, the GOP-controlled House passed a $42.3 billion budget for the government’s homeland security programs that would prohibit the use of federal funds for collective bargaining for TSA workers. But that provision is expected to face stiff resistance in the Democratic-controlled Senate.