San Francisco - Apple has unveiled a taller, lighter and slimmer 4G-enabled iPhone 5 at an event in San Francisco.
The model has a larger screen and it is 20% lighter than its predecessor, the iPhone 4S.
The device's new size allows it to display an extra row of app icons on its home screen.
Apple said the handset would work on Everything Everywhere's (EE) 4G LTE network.
The news is likely to give EE - which runs the local Orange and T-Mobile services - an advantage against its rivals which will not launch the higher-speed data service until 2013.
Apple chief executive Tim Cook called the launch "the biggest thing to happen to iPhone since the iPhone."
The California-based company called the iPhone 5 "the thinnest smartphone in the world," with a glass and aluminum body that is 18 percent thinner and 20 percent lighter than iPhone 4S. However, it does not feature an NFC (near field communication) chip to allow it to make touchless payments.
Apple will start taking orders for the phone Friday and begin shipments on September 21 in the United States, Canada, Britain, France, Germany, Australia, Hong Kong, Singapore and Japan, and the phone will be available in 100 countries by the end of the year.
The new screen offers a 16:9 ratio, matching that of widescreen televisions.
But its 4in (10.2cm) size remains smaller than rival displays used by Samsung, Nokia, Motorola, LG, HTC and Sony's flagship models.
Phil Schiller - Apple's vice president of worldwide marketing, who unveiled the device - said existing apps would be shown with black borders until developers updated their products.
The handset also features a new Apple-designed chip, called the A6. Mr Schiller suggested this made it twice as powerful as the earlier model.
The camera is an eight megapixel model - the same as in the iPhone 4S, and a lower specification than LG and Sony's most recent devices.
However, Mr Schiller said the equipment and associated software meant the iPhone would create better photographs in low light than before.
The handset also uses a new, smaller, socket for its charger. This means owners will need to use an adapter to plug the device into existing speakers and other equipment.
The handset does not offer wireless charging like Nokia's Lumia 920.
It will be sold with either 16 gigabytes, 32GB or 64GB of storage.
In addition to launching the new model, Apple will continue to ship versions of the iPhone 4S and the iPhone 4, but is phasing out 2009's iPhone 3GS.
Battery life, a key complaint of smartphone users, is extended to eight hours with mobile phone and browsing and 10 hours if Wi-Fi connections are used.
Despite the fact that the iPhone 5 lacks several features found on its rivals, one analyst at the presentation thought it would prove popular.
Apple also announced iTunes, its media player and store for Macs and PCs, was being redesigned and would be released in October, and it also unveiled new iPods.
Analysts expect Apple to sell tens of millions of iPhone 5 models in the coming months with shipments between 48 million and 53 million iPhones in the fourth quarter and up to 260 million in 2013.