Apple CEO Steve Jobs shows off the new iPhone during his keynote address at MacWorld Conference and Expo in San Francisco on Tuesday. ((Paul Sakuma/Associated Press) )

Cisco Systems announced Wednesday it has filed a lawsuit against Apple Inc. over the name of the iPod manufacturer's new mobile phone.

The company filed the suit in the U.S. District Court in California seeking to prevent Apple from infringing upon Cisco's registered trademark for the name iPhone.

Apple CEO Steve Jobs unveiled the new product — which he called the iPhone —on Tuesday at the opening of the annual Macworld electronics show.

But even as Jobs was making the announcement, the question of naming rights had still been unresolved.

Cisco obtained the iPhone trademark in 2000 after completing the acquisition of Infogear, which previously owned the mark and sold iPhone products for several years. Infogear's original filing for the trademark dates to March 20, 1996.

And in December,a division of Cisco Systems called Linksys also came out with their own product — a wireless Voice over Internet Protocol or VoIP phone — that goes by the name iPhone.

"Cisco entered into negotiations with Apple in good faith after Apple repeatedly asked permission to use Cisco's iPhone name," said Mark Chandler, senior vice-president and general counsel of Cisco in a statement.

"There is no doubt that Apple’s new phone is very exciting, but they should not be using our trademark without our permission."

Apple's iPhone is a mobile phone using touch-pad technology similar to the iPod portable music player. Jobs said on Tuesday the phone would "leapfrog" past the current generation of hard-to-use smart phones.

Cisco is seeking injunctive relief to prevent Apple from copying Cisco's iPhone trademark.