Delta Air Lines said Tuesday that it was doubling, to $50, the fee for checking a second bag, three months after airlines initially began imposing the charge.
The airline is also raising fees for checking special items, like surfboards, as well as additional luggage beyond two bags. Bags that exceed Delta's weight allowance will also cost more.
Delta did not join other major airlines this summer in charging to check a first bag on flights within the United States. But Delta was among the airlines to begin charging $25 in May for a second bag.
The airline said Tuesday that it was increasing its second-bag fee to help offset increases in fuel prices, which have nearly doubled in the last 12 months. The increased second-bag fee, and the other fees, will apply to passengers who book tickets on or after Thursday for travel after next Tuesday.
On domestic flights, the fee on Delta for checking a third, fourth or fifth bag, now $80 for each bag, will rise to $125 apiece.
"Fewer than 20 percent of our customers check a second bag; I would imagine that it would be even less for a third," a Delta spokeswoman, Betsy Talton, said. "It's still a good value when compared with shipping or luggage services."
She declined to estimate how much the new baggage fees have raised. Other airlines have said the fees, for both a first and second bag, have generated tens of millions of dollars.
First-class passengers, international travelers and elite members of Delta's frequent-flier program will still be allowed to check two bags at no charge. First-class and elite travelers can check up to three bags at no charge on international flights; a third bag will now cost a coach-class passenger traveling overseas $150.
Items that are 62 to 80 inches long, including athletic equipment like surfboards and skis, will cost $175 to check after Tuesday on all flights. They now cost $150.
Delta is also increasing its charges for heavy baggage, regardless of whether it is included in a free baggage allowance. A bag that weighs 51 to 70 pounds will cost the traveler $90 to check in the United States, and $150 on an international trip, up from $80.
A bag weighing from 71 to 100 pounds will cost as much as $300 to check on an international trip, compared with $150.