Southwest Airlines, for example, only makes its fares available on its website. Delta Airlines last month told three sites—CheapOair, OneTravel and BookIt—that their services were no longer required. And American Airlines stopped using Orbitz on December 21st because of a contract dispute. Now American is also embroiled in a dispute with Expedia, which has suspended the sale of the airline's flights on its site (although they remain listed on Expedia's corporate travel site, Egencia).

The reason behind Expedia's decision is American's introduction of a ticket-selling system that requires agencies to link to its new "Direct Connect" platform, rather than use traditional distributors such as Amadeus and Sabre. American says Direct Connect will "help travel agencies help their own customers by giving them access to customized choices." But Expedia responds that American's new commercial strategy is "anti-consumer and anti-choice," and will result in "higher costs and reduced transparency for consumers, making it difficult to compare American's ticket prices and options with offerings by other airlines."

Google’s $700 million acquisition of ITA Software, which powers many of the Web’s most popular travel search engines, has ruffled more than just a few feathers in the travel industry, The New York Times’ colleague Mickey Meece wrote on Monday.

Google, which announced its intent to purchase the company in July, has faced a wave of resistance from competitors, who are calling on regulators to block the deal on antitrust concerns. In October, several travel search sites, including Expedia, Travelocity and Kayak, formed a coalition called FairSearch.org to oppose the deal, arguing that Google could use ITA to “manipulate and dominate” the travel market, the group said in a recent statement.