WASHINGTON (Reuters) - The Teamsters union won an election on Monday to represent mechanics at United Airlines, a unit of UAL Corp (UAUA.O: Quote, Profile, Research), the labor group said.

The Teamsters easily gained majority support to unseat the Aircraft Mechanics Fraternal Association (AMFA), according to a final counting of the ballots.

The results must be certified by the National Mediation Board (NMB).

United's 10,000 active and furloughed mechanics have been represented by AMFA since 2003. Teamsters represent 40,000 airline workers, including 9,000 mechanics and related employees at 11 airlines, including AirTran Holdings (AAI.N: Quote, Profile, Research) and Frontier Airlines Holdings Inc FRNT.O.

"The campaign is over and it is now time to see the Teamsters turn their promises into action," said AMFA National Director Steve MacFarlane.

United, like other major airlines, has worked for several years to cut costs. Labor ranks in the top two expenses for those carriers.

"United is committed to working productively with the elected representatives of our employees, and we look forward to working with the Teamsters/AMFA to ensure United's position as a strong, profitable and competitive airline," a UAL spokesman said in a statement.

(Reporting by John Crawley; Additional reporting by Kyle Peterson; Editing by Brian Moss)