Airline shares fell on Monday after Delta said a key measure of revenue grew less than it had expected in May because of fare competition from another airline.
The news unnerved investors because a big selling point for airline stocks has been the idea that airlines have been relatively united in charging enough for tickets to cover growing fuel costs. The industry used to be marked by fare wars, followed by losses. Airline executives have been trying to convince investors that those days are over.
Delta saw the biggest decline in percentage terms, falling $1.30, or 11.3 percent, to $10.21 in afternoon trading. On Monday morning Delta said passenger revenue for each seat flown one mile had risen 6 percent in May. As recently as May 17, it had predicted revenue growth of 7 percent. The airline said the smaller-than-expected gain was because of fare actions by an unnamed competitor in the second half of the month.
US Airways Group Inc. fell $1.32, or 10.4 percent, to $11.32. United Continental Holdings Inc. was down $1.85, or 7.6 percent, to $22.51.
Southwest Airlines Co. fell 24 cents, or 2.7 percent, to $8.70, and JetBlue Airways Corp. fell 25 cents, or 4.8 percent, to $4.91. Shares of Alaska Air Group Inc. fell $1.57, or 4.6 percent, to $32.24.