FORT WORTH, Texas For more than three years, the nation's airlines have grappled with persistently high fuel costs. But they haven't seen prices quite like this.

Jet fuel prices reached $2.54 a gallon Friday, the highest price on record. The price spike was driven by the surge in crude oil prices, which topped $90 per barrel for the first time ever this week. Some energy analysts predict prices could rise even higher, perhaps topping $100 per barrel.

If they persist, executives and analysts say the high prices could seriously threaten the airline industry's fragile turnaround.

The airlines have greatly improved their fuel efficiency in recent years and used fare increases and hedging contracts to blunt the impact. But the high costs are impossible to entirely mitigate for an industry that burned nearly 20 billion gallons of fuel last year.

"These prices are very upsetting and worrisome," said George Hamlin, a longtime industry analyst with ACA Associates. "The industry is very concerned right now."

Executives at Fort Worth-based American Airlines said every penny increase in the price of jet fuel costs the carrier about $30 million annually. During the third quarter, the airline spent more than $1.7 billion on fuel. It was one of the few times in the airline's history that the fuel bill was higher than the cost of labor, which is traditionally its largest expense.