CHICAGO - The 1,400 U.S. mechanics who maintain United Parcel Service Inc's worldwide fleet of 263 aircraft authorized a strike against the company, union officials said on Tuesday, though contract talks between the company and the workers will continue later this month.

The mechanics, members of Teamsters Local 2727, will not go on strike as a result of the action. The vote expresses their willingness to walk off the job if ongoing negotiations hit an impasse and union leaders call a strike.

Atlanta-based UPS, the world's largest package delivery company, says the vote was just a tactic that will not affect talks with the machinists, which began in October 2006 and continue under the supervision of a federal mediator.

The Atlanta-based company points out that more talks are scheduled for late September, a sign the process is far from deadlocked.

Until the talks officially break down, and the union endures at least one cooling-off period, a strike -- even one authorized by members -- would be illegal under the U.S. Railway Labor Act, the Depression-era legislation that governs the company's air unit. (Reporting by James B. Kelleher, Editing by Dave Zimmerman)