"Yahoo is poised to launch an ad network for small Web publishers styled on a similar offering from Google, sources familiar with the plan told CNET News.com, a move that promises to sharpen competition between the search giants.

While Yahoo and Google already go head-to-head for major search advertising partners such as America Online, Google has largely enjoyed a monopoly serving its signature text-only ads to smaller publisher Web sites, including ever-more-popular blogs."

Background article from CNET
URLs:

http://news.com.com/Yahoo+seeks+to+expand+in+Google+territory/2100-1024_3-5609792.html