Looks like while American Airlines has kissed and made up with one online site, it’s launching a war against another.

Users of meta-search engines Kayak.com and Sidestep.com (also owned by Kayak) can now find schedules and fares directly from American Airlines, which is owned by parent company AMR.

This summer, Kayak stated that it terminated its relationship with AA after the online agency “refused to concede to AA’s demand to not display AA fares available through online travel agencies alongside those from AA.com.”

According to Kayak’s CEO Steve Hafner, American asked the online site to direct all fare searches to American’s Web site, rather than displaying fares from AA.com alongside fares from booking sites Orbitz and Cheaptickets.

As to how the two sides came to a resolution, the details are being kept under wraps. American Airlines spokesman Ned Raynolds responded that a legal settlement was involved, but “details and terms are confidential.”

As for Kayak? When contacted, their VP of Marketing Drew Patterson read out loud from press releases. Literally. Apparently, Kayak is “delighted” to be working with American again.

A quick search on Kayak shows that the site is NOT showing fares from Orbitz and Cheaptickets alongside AA fares, although it does so for other airlines. Guess AA won this battle.

On the flip side, AA has filed a lawsuit against Yahoo! for trademark infringement, claiming the search engine is selling the airline’s trademark and related terms for ads that may divert business from AA. So, for example, if you type in AAdvantage—the name of the airline’s frequent-flier program—sponsored ads from competitor Web sites may appear using that search term.

This summer, American filed suit against Google in August 2007 for the same reason, which later reached a confidential settlement.

Related links: Cranky Flier, Newsweek, Flight Global, Wall Street Journal, Motley Fool, Associated Press

By Managing Editor Sarika Chawla for PeterGreenberg.com.

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