KEY POINTS
  • U.S. airline stocks tumble, posting losses that outpaced the broader market.
  • Delta says its revenue did not grow as quickly as it anticipated in the fourth quarter.
  • Delta is expected to report fourth-quarter and full-year results in mid-January.
Delta Airlines Airbus A330-200 airplane landing at London's Heathrow Airport.

Shares of U.S. airlines tumbled Thursday after Delta Air Lines forecast slightly lower revenue growth, following downbeat sales projections from iPhone-maker Apple that stoked concerns of a global slowdown.

Delta shares fell nearly 9 percent, their steepest percentage decline in more than six years, to close at $45.61. American Airlines shed more than 7 percent, recovering slightly after hitting its lowest price since July 2016. United Airlines lost 5 percent, while Southwest Airlines ended the session more than 3 percent lower.