Apple Inc on Wednesday unveiled the iPhone 5, saying it's thinner and lighter than the previous model, even though it has a bigger screen. The new phone hits stores in the United States and several other countries September 21.

Apple marketing head Phil Schiller unveiled the year's most eagerly awaited phone at an Apple event in San Francisco.

The release is expected to help Apple recapture attention and revenue after it lost the lead in smartphones to Samsung this year.

Apple's announcements were largely in line with investor expectations, and their response was tepid. Apple shares rose $5.13, or 0.8 per cent, to $665.72 in afternoon trading. Shares have jumped as expectations rose for the iPhone 5, rallying 16 per cent since Apple's latest earnings report in July.

The first launch countries are Australia, Canada, France, Germany, Hong Kong, Japan, Singapore and the UK. A week later, the phone will be available in 22 more countries, including Italy, Poland and Spain. Prices for overseas locations were not announced.

As expected, the iPhone 5 screen is taller than on the iPhone 4S, making room for another row of icons.

The bigger screen moves Apple somewhat closer to competing smartphones, but the iPhone is still small compared to its main rivals. Samsung has increased the screen size of its flagship phone line every year, and it's now about 45 per cent larger than the one on the new iPhone.

The new iPhone is lighter than Samsung's new Galaxy S III. Schiller said the screen is 18 per cent thinner and 20 per cent lighter because of new technology that eliminates a separate touch-sensing layer in the screen. The new phone is made entirely of glass and aluminium.

The iPhone 5 will also come with the capability to connect to the fastest new wireless data networks, both in the US and overseas. That's another feature that was widely expected.

Sales of Apple's iPhones are still strong. Samsung Electronics Co benefited from having its Galaxy S III out in the US in June, while Apple was still selling an iPhone model it released last October.

Amid expectations of a new iPhone, Amazon, Nokia and Motorola all tried to generate interest in their products last week, hoping that a head start on the buzz will translate into stronger sales.

Makers of consumer electronics also are refreshing their products for the holiday shopping season.

One big change: The new iPhone is getting a new connector to attach to computers and chargers. It had been using the same one from the iPod. Schiller said the old connector has "served us well for nearly a decade, but so much has changed".

That means the new iPhone won't be compatible with old accessories, though Schiller said accessory makers are already working to update their products. Apple will sell an adapter to work with older accessories.

- AP