After a backlash from some of its elite fliers, the world’s biggest carrier has halted a program on Delta Air Lines-operated aircraft that allowed customers to purchase better seat assignments on certain flights.

Atlanta-based Delta Air Lines Inc. in late October began offering coach customers on certain flights the ability to purchase a better seat assignment in their cabin for $5 to $25, depending on distance traveled and seat location. The “coach choice seats” represented less than 10 percent of all seat assignments available on Delta-operated flights, the airline said at the time.

But in an e-mail last week to elite fliers, Jeff Robertson, vice president of loyalty programs for Delta, said that some Medallion members of the carrier’s frequent-flier program were upset that their access to preferred seats without charge at the time of booking was restricted as a result of the new program.

“Retaining your long-term loyalty is of paramount importance to us, and we’re not afraid to change course when we need to,” Robertson said.

He said Delta would revert to the original preferred-seat program, offering Medallion members unrestricted access to preferred seats.

Customers on Northwest-operated flights continue to be offered choice seats for purchase, Talton said. Delta acquired Northwest Airlines on Oct. 29.