Delta Air Lines Inc. and Continental Airlines Inc. will begin charging customers the highest fees in the industry for checked bags this week, setting up other carriers to do the same.
Delta raised its checked-baggage fees last week to $25 for the first bag and $35 for the second, up from $15 and $20, respectively. Continental said it matched these increases Friday.
In August, US Airways Group raised its bag fees to $25 and $35. Ancillary fees, such as those levied for checked luggage, have become an important driver for revenue growth. Putting pressure on the industry is a recent jump in benchmark crude prices, which hit a 15-month high earlier this week.

