The International Brotherhood of Teamsters airline division will hold an election among pilots at Las Vegas-based Allegiant Air on union representation.
The low-cost carrier employs 363 pilots, according to the union.
"We strongly believe that Allegiant's success is attributable in large part to our pilots and the direct, open relationship we have with them," says Maurice Gallagher Jr, chief executive and chairman of the airline, in a statement. "We are committed to ensuring a fair election."
Allegiant operates 55 Boeing MD-82/83/88 aircraft, two MD-87s and three Boeing 757-200s, according to Flightglobal's Ascend database.