American Airlines on Tuesday pulled its fare listings from online travel sites operated by Orbitz because the companies failed to agree on terms for a new contract.
American said it also will pull US Airways flights starting September 1, cutting thousands of routes and fares from travel sites.
American and Orbitz have clashed before over terms and the latest dispute appeared unlikely to threaten rival online travel companies such as Priceline, Travelocity and Expedia, that continue to post American fares.
An American Airlines spokesman, Josh Freed, said the company reached agreements with some of these sites without a problem.
"In general, our strategy is to make our fares widely available," Freed said.
Orbitz declined to comment on the talks, but said its sites still carry fares from hundreds of airlines "eager to capture the revenue American is choosing to forego."
Both companies noted that Orbitz for Business was not affected by American's move.
American said it was not able to reach a deal with Orbitz after negotiations that began before American and US Airways completed their merger last December.
Customers who bought tickets on orbitz or cheaptickets will be able to use the tickets for travel. But changes to the reservations must now be made through either the American or US Airways reservations departments, American said.