ATLANTA — Delta Air Lines is imposing new or higher fees on a host of travelers, including frequent fliers, passengers traveling with pets and people booking their tickets over the phone.

The fee changes, which go into effect today, come as Delta and its competitors try to boost revenue to offset record fuel prices. Delta did not say how much revenue it expected from the fee changes, but the parent company of United Airlines has said new luggage fees would generate more than $100 million annually. The industry has had mixed success with fare increases.

"Desperate people do desperate things," said Minneapolis airline expert Terry Trippler.

Betsy Talton, a spokeswoman for Delta Air Lines Inc., the country's third-largest carrier, said Delta's additional fees are largely in response to fuel prices and said that the most recent attempts by Delta to raise fares "have not been successful because there's also a need for Delta to be competitive."

Talton said Delta continuously reviews all aspects of its business "to make sure our business model is aligned with current costs."

She said she did not know how much extra revenue the airline expected to generate annually from the fee changes.

One of the changes most likely to rankle frequent fliers is a new $25 "handling charge" for any Delta award ticket booked through a Delta representative that includes a segment on another airline.

In the past, people who redeemed their Delta SkyMiles for free tickets on partner carriers such as Northwest and Continental did not pay a "handling charge" whether they booked it on the phone or online.

The fee for booking an award ticket on another airline through a Delta representative helps Delta recoup charges from the other airline, Talton said. Booking Delta award travel on another airline will not carry the new $25 fee if done online, Talton said.

The "handling charge" would be on top of the fee Delta charges for booking travel over the telephone, which is increasing today to $25 from $20.

It was not clear if Delta's partner carriers will impose a "handling charge" on their frequent fliers booking award tickets on Delta.

Michelle Aguayo-Shannon, a spokeswoman for Eagan, Minn.-based Northwest Airlines Corp., would not comment on the issue. Mary Clark, a spokeswoman for Houston-based Continental Airlines Inc., said Continental does not have such a fee. She said she couldn't comment on any potential "future pricing actions."

Delta, based in Atlanta, also said carrying a pet in the cabin will cost $100 instead of $75, starting today. The oversize bag fee will be $150 instead of $100.

The unaccompanied minor fee will be $100 on all flights instead of $50 for nonstop flights and $100 for connecting flights.

In February, UAL Corp.'s United Airlines said it would in May start charging domestic passengers $25 to check in a second piece of luggage. Certain elite fliers are exempt from that fee.

Last week, Northwest said it would begin charging $25 each way for a second checked bag. It also raised its fee for a third bag from $80 to $100. And it doubled its $25 fee for bags over 50 pounds.