Delta is the latest airline to raise baggage fees as fuel costs surge

Delta Air Lines raised its first checked bag fee by $10 to $45, effective for tickets purchased starting this week, making it the third major U.S. carrier to increase baggage prices this year.

Travelers $TRV checking a single bag on domestic or short-haul international routes will now pay $45, while fees for additional bags will rise to $55 for a second and $200 for a third, according to CNBC. "These updates are part of Delta's ongoing review of pricing across its business and reflect the impact of evolving global conditions and industry dynamics," the company said in a statement.

United Airlines and JetBlue Airways raised their checked bag fees last week. For most United travelers, the new structure sets prepaid first-bag fees at $45, climbing to $50 for those who settle the charge in the final 24 hours before departure, according to ABC News. United's increase was its first in two years.

The fee increases come as jet fuel prices have climbed sharply. According to Airlines for America data cited by CNBC, Monday's average jet fuel price across major U.S. markets hit $4.69 per gallon — a figure that represents an almost 88% surge since joint U.S.-Israeli strikes on Iran on Feb. 28. Global supplies of crude oil and refined fuels have tightened considerably, with the Strait of Hormuz shipping lane staying largely shut for roughly the past month.

Fuel is airlines' largest expense after labor. Speaking to ABC News in March, Kirby warned that passengers would probably feel the effects of the conflict through higher costs, and in a separate message to staff he put a number on the risk, estimating that sustained fuel prices at current levels could add $11 billion annually to United's expenses.

With Delta's first-quarter earnings due this week, questions about fuel cost recovery are expected to dominate the conversation with analysts.