Cisco Systems Inc. said on Wednesday that it filed a lawsuit against Apple for infringing its iPhone trademark after Apple unveiled a multimedia phone of the same name.

The suit was filed in the U.S. District Court for the Northern District of California.

Cisco obtained the iPhone trademark in the year 2000 after it acquired a company called Infogear, which previously owned the mark and sold iPhone products for several years. Infogear's original filing for the trademark dates back to March 20, 1996.

Linksys, a division of Cisco, has been shipping a new family of iPhone products since early last year. Last month, Cisco launched its own "iPhone," unveiling a VoIP phone for the home.

According to media reports, Cisco VP Charles Giancarlo read this prepared statement at CES Wednesday: "Given Apple's numerous requests for permission to use Cisco's iPhone trademark over the past several years and our extensive discussions with them recently, it is our belief that with their announcement today, Apple intends to agree to the final document and public statement that were distributed to them last night and that addressed a few remaining items. We expect to receive a signed agreement today."

"There is no doubt that Apple's new phone is very exciting, but they should not be using our trademark without our permission." Mark Chandler, senior vice president and general counsel of Cisco said.

The highly volatile shares of Apple, which was not immediately available for comment, initially fell 1.3 percent in after-hours trade following the announcement and then pared the loss to less than half a percent.

Apple on Tuesday introduced its hotly awaited iPhone in a move that could vault the iconic company into an instant leader in the world cellphone market.

The phone will combine wireless technology, iPod capabilities and new features like Visual Voice Mail, and allows users to go directly to any of their voice messages without listening to any of the prior messages.

The iPhone will be commercially available in June. A 4 GB version will be available for 499 dollars and an 8 GB version will cost 599.

Editor: Yan