by , 9:50 AM EDT, June 16th, 2006

Colorado-based JP Enterprises filed a suit against Internet search service Yahoo! for purchasing AdWord advertising on Google to draw consumers to Yahoo!-based services. JPEnterprises owns the lovecity online dating service, and claims that Yahoo! placed keywords in Google AdWords advertising in an effort to draw consumers to its own online dating services, according to the Denver Post.

HDVE LLC and Spark Networks were also named in the suit.

Google offers a sponsored advertising feature called AdWords. By including appropriate keywords, an advertiser's link appears at the top of a search results page. Even though sponsored links are clearly marked, some users may not realize that they are not regular search results.

Google and Yahoo! are competitors in the Internet search engine market, and competition between the companies has been on the rise. Both have expanded beyond basic search features and offer news, email, and other free services to draw viewers to their sites. Purchasing advertising on a rival's Web site, however, wasn't exactly an expected move.

Both companies own other businesses geared towards enhancing their own services. Google, for example, recently purchased SketchUp, and now offers a free version of the software for personal use and creating Google Earth 3D images. Among its assets, Yahoo! owns online dating services.

As noted by a reader in the comments below, JP Enterprises appears to have taken exception to the fact that "lovecity," "www.lovecity," and "lovecity.com" were all among the AdWords purchased by Yahoo! at Google.

Yahoo! and HDVE LLC were not available for comment. Spark Networks is not commenting on the case.