JetBlue has raised checked-bag fees for the third time in less than a year as rising fuel and operating costs weigh on airline profits. The new prices apply to many economy passengers, with some exceptions for customers who have a co-branded JetBlue credit card or elite frequent-flyer status.

During nonpeak periods, checking a first bag costs $50 if purchased more than 24 hours before departure, up from $45. The fee is $60 when paid within 24 hours of departure. During peak periods, including holidays and summer, the advance-purchase fee has risen from $49 to $55, while a bag bought within 24 hours of departure costs $70.

JetBlue said the increase is intended to offset higher fuel and operating expenses while keeping base fares competitive. The airline also said the fees allow customers to pay for checked baggage only when they need it.

Jet fuel, the airline industry's largest expense after labor, has roughly doubled this year since the start of the Iran war in February. The U.S. Energy Information Administration put the price of jet fuel in the U.S. Gulf of Mexico at $4.44 per gallon on Tuesday. Other major U.S. airlines raised baggage fees earlier this year after JetBlue made a similar increase.

Sources: CNBC Markets.