American Airlines is suing Yahoo, claiming that when users enter American's trademark terms such as AAdvantage they get referred to rivals who pay Yahoo for the advert. The case is similar to one that AA settled against Google and it claims that it has to run a "corrective" advertising campaign to counter Yahoo’s activities.

In the Google case, each side agreed to pay its own legal fees, and American got nothing from Google. But Google searches for "American Airlines" or "AAdvantage" no longer produce paid ads along the right side of the portal screen. Yahoo said that its trademark policies are good, and it is prepared to defend them in court.

Basically, Yahoo thinks it is enough to allow advertisers to use the trademark terms of others only if it refers to the trademark "without creating a likelihood of consumer confusion."

Tim Smith, a spokesman for American, said the airline saw value in Internet searches and hoped to continue a "professional and amicable relationship" with Yahoo.  After the lawsuit is over, we guess.