Blue Nile Inc. was sued for trademark infringement and unfair competition by Hearts On Fire Inc., Bloomberg News reports.

Hearts On Fire says the Seattle-based Internet jewelry and diamond retailer is using keywords on the Web to misdirect those who are searching for Hearts On Fire Diamonds, Bloomberg reports. Blue Nile, which isn’t an authorized seller of Hearts On Fire diamonds, bought the search term “hearts on fire” from Webcrawler.com, a search engine that searches other search engines, according to the June 20 complaint filed in federal court in Boston.

Searchers who use that phrase end up at the Blue Nile Web site, Boston-based Hearts On Fire said in its court papers.

Blue Nile’s use of Hearts On Fire’s trademark as a search term violates the company’s trademark and “misappropriates the goodwill” the diamond cutter has created over the years, court papers reportedly say.

Hearts On Fire asked the court to order Blue Nile to quit infringing the trademark, and for money damages, including profits relating to the infringement, Blue Nile . It also seeks attorney fees.

Bruce E. Falby and Robert P. Sherman of Chicago’s DLA Piper represent Hearts On Fire.

JCK