JetBlue shares plunged 9 percent — among its worst one-day declines in a decade — after the airline reported a $120 million second-quarter loss on higher fuel expenses and gave a cautious outlook for the rest of 2018.

Executives of JetBlue, the nation's sixth-biggest airline, said Tuesday they will respond by reducing planned growth and redirecting some West Coast flying to more profitable transcontinental routes.

In the past few days, JetBlue has announced it would cut an undisclosed number of jobs at its headquarters in Long Island City, New York, and it raised fares — by $5 each way on most U.S. flights, and up to $50 each way on its premium transcontinental service called Mint.

Earnings season is off to a turbulent start for U.S. airlines. Last week, United Airlines stock soared nearly 9 percent after it posted a surprisingly large profit and gave a glowing forecast for the rest of 2018.

JetBlue stock went in the other direction, however, after the company reported Tuesday that it flipped to a loss for the April-June quarter after earning $207 million in the same period last year.

Revenue rose 5 percent, and JetBlue executives said demand for last-minute travel has been strong. Still, the average JetBlue passenger's one-way fare dipped to $170.08, down $1.22 from a year earlier.

Meanwhile, JetBlue's fuel spending spiked 51 percent, an increase of $166 million from a year earlier.

Excluding a write-down in the value of its Embraer E190 jets, which JetBlue plans to replace, the company said that it earned an adjusted profit of 38 cents per share, which was 2 cents better than the average estimate of seven analysts surveyed by Zacks Investment Research.

JetBlue said that with strong travel demand it expects a closely watched revenue per mile figure to be flat to up 3 percent in the third quarter. J.P. Morgan Chase analyst Jamie Baker said the forecast seemed adequate but he had hoped for more.

On a call with executives, Baker questioned JetBlue's strategy of rapid growth, saying, "It seems like the more you grow, the less you earn."

CEO Robin Hayes said growth has been focused in places where JetBlue does well, such as Boston and Fort Lauderdale, Florida. He conceded that the airline's profit margins have been disappointing, falling behind the airline-industry average, "and I don't think that we should be using higher oil prices as an excuse."

JetBlue is often seen as good at generating revenue but less skilled at controlling costs, and that image won't change with a forecast that non-fuel costs will rise again in the third quarter.

Executives said that starting in September, the airline will shift some West Coast flying at Long Beach, California, to transcontinental flights, and it is already scaling back in Puerto Rico, which is still dealing with the aftermath of last year's Hurricane Maria.

In afternoon trading, shares of JetBlue Airways Corp. were down $1.84, or 9.3 percent, to $17.97. The shares opened the session down 12.8 percent in 2018.