Cisco Systems has given Apple a further extension on the deadline to respond to its lawsuit concerning the iPhone name, the company said late yesterday.

Apple was hit with a trademark infringement lawsuit from the networking vendor the day after it unveiled a new mobile phone under the name iPhone at January's Macworld Expo in San Francisco.

Cisco says its Linksys division owns the trademark on "iPhone" and filed a lawsuit seeking an injunction against Apple using the name.

Yesterday Cisco said it had agreed to a request from Apple for more time.

"Cisco has agreed to give Apple an extension until Wednesday, 21 February," the company said. "Cisco is fully committed to using the extra time to reach a mutually beneficial resolution."

When Cisco sued Apple on 10 January it revealed that the two companies had been talking about the iPhone name for about two years and were close to a deal on 8 January, which was the day before the Apple launch event. When Apple chief Steve Jobs went ahead on 9 January and announced the phone, he did so before an agreement between the two companies had been reached and that pushed Cisco to file its lawsuit.

A previous extension was granted Apple by Cisco on 1 February, at which time Cisco said it wanted an agreement on "trademark use and interoperability,” which lends credibility to earlier media reports that Cisco might back down over the trademark issue if the iPhone were made compatible with its networking gear.

Just how serious Apple views the issue or how close the current talks are to a deal is unknown.

A few days after being hit with the lawsuit Natalie Kerris, Apple's Director of music public relations, told IDG's Macworld that the company thought the lawsuit was "silly".

Linksys launched its iPhone in late December, just as buzz was building about the possibility of a mobile and music player combo from Apple. The Linksys iPhone is a cordless telephone with base station that attaches to the internet. It means calls can be made from the handset over Skype without the need for a personal computer.

Apple's iPhone is a GSM mobile phone married with an iPod that runs on Apple's Mac OS X operating system. The phone is due to be released in the US in the middle of this year through a deal with provider Cingular Wireless. Models for international markets, including Europe, are due out sometime after the US launch.