US carrier Cingular has inadvertently confirmed the exact date for Apple's iPhone launch.

The date coincides with Apple's Worldwide Developers Conference, which begins in San Francisco on 11 June and runs until 15 June. 

The launch date was confirmed by a Cingular sales representative contacted by a journalist at News.com.

Dennis Strigl, president and chief executive at Verizon Communications, which declined to take on the iPhone, claimed that his company is not concerned by the launch. 

"If you're looking at a phone at a $400 or $500 price point, we know from our experience with PDAs that it's a very small market. It's a niche market," he said.

Strigl also believes that the launch might help other phone manufacturers and carriers by highlighting the music capabilities of all mobile phones.

"We have been struggling in the music business, in that it's been difficult to create attention for music on a phone," he said.