WASHINGTON, Jan 28 (Reuters) - A U.S. appeals court on

Tuesday blocked the Biden administration's 2024 rule requiring

upfront disclosure of airline service fees, saying the

Transportation Department (USDOT) had not complied with

procedural rules.

The court ruling said the department had authority to write

fee disclosure rules that specifically address "unfair or

deceptive practices being conducted by airlines." However, the

court also said the department should have allowed airlines an

opportunity to comment on a study used by USDOT that looked at

the impact of the fee disclosure rules.

The court sent the rule back to USDOT to give it a

chance to address the procedural error. The department, which

has been under control of the Trump administration since Jan.

20, did not immediately comment on whether it plans to proceed.

Regulations issued by USDOT in April required airlines and

ticket agents to disclose service fees alongside the airfare, in

a move to help consumers avoid unneeded or unexpected fees, but

they were put on hold pending a legal challenge.

Airlines including American Airlines ( AAL ), Delta Air

Lines ( DAL ), United Airlines, JetBlue ( JBLU ) and

Alaska Airlines, joined by trade group Airlines for

America and the International Air Transport Association, sued in

May to overturn the rules.

Airlines for America said it was studying the ruling and

did not comment.

The Biden rules had set an October 2024 deadline for

airlines to disclose fee data to third-party ticket agents, and

on their own websites by April 2025.

The industry previously said the rule would require

airlines to "spend millions" to re-engineer their websites.

In April, USDOT said consumers were overpaying $543

million in fees annually, generating additional revenue for

airlines from passengers surprised by having to pay a "higher

fee at the airport to check a bag."

Major airlines charge such higher fees if travelers do

not pay in advance or wait until flight time. Several U.S.

airlines boosted fees last year for checked baggage.

The rule would end "bait-and-switch tactics some

airlines use to disguise the true cost of discounted flights,"

added USDOT.

U.S. airlines collected $7.1 billion in baggage fees in

2023, up from $6.8 billion in 2022.