Google has become the exclusive provider of pay-per-click text ads on CNN.com, one of the most visited news web sites in the world, displacing rival Yahoo.
Yahoo had been the provider of search-engine services and pay-per-click advertising for CNN.com since 2004. At the time, Yahoo took that contract away from Google.
The deal announced on Tuesday calls for CNN.com to use Google's AdSense advertising program exclusively for the contextually relevant, pay-per-click ads it runs on its pages, the companies said. CNN.com also uses Google's search engine.
"This is an important deal for Google because CNN.com has a lot of traffic and high quality content. The agreement provides an opportunity for our advertisers to target CNN.com and get high quality traffic for their ads," said Google spokesman Brandon McCormick.
However, CNN apparently still uses Yahoo's search engine and pay-per-click ads on the International edition of CNN.com.
Yahoo didn't immediately reply to a request seeking comment. A CNN spokeswoman confirmed that Google replaced Yahoo as the text ad provider on CNN.com, but at press time she hadn't replied to a subsequent inquiry about CNN International.
The news of Google's win comes at a time when Yahoo's new Panama pay-per-click advertising platform has been in place in the U.S. now for a little over six months.
Yahoo, whose financial performance in the past year has been disappointing and has led to a major company reorganisation, is counting on Panama to help boost its pay-per-click advertising business.
Pay-per-click ads, which are matched to the topic of search-engine queries and of regular Web pages, make up the single largest segment of online ads, accounting for about 40 percent of all revenue. Google generates most of its revenue from sales of these text ads, which, when clicked upon, take people to advertisers' pages.
Advertisers pay only when people click on these ads. In other online ad formats, advertisers pay when ads are displayed.
According to Yahoo, Panama significantly improves on its ability to match ads to search queries and web pages. The company has said that this improved targeting will increase the number of times users click on the pay-per-click ads it serves up in its search engine, web pages and partner web sites.