SAN FRANCISCO (AP) -- Cisco Systems Inc. said Wednesday it is suing Apple Inc. in federal court over Apple's use of Cisco's registered iPhone trademark for its new handheld device.

Cisco has owned the trademark on the name "iPhone" since 2000, when it acquired InfoGear Technology Corp., which originally registered the name.

And three weeks ago, Cisco's Linksys division put the trademark to use, releasing an Internet-enabled phone called "iPhone" that uses the increasingly popular Voice over Internet Protocol, or VoIP.

On Tuesday, Apple unveiled the iPhone, its "game-changing" touch- screen-controlled cell phone device that plays music, surfs the Web and delivers voicemail and e-mail.

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

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

"Today's iPhone is not tomorrow's iPhone. The potential for convergence of the home phone, cell phone, work phone and PC is limitless, which is why it is so important for us to protect our brand," Chandler added.