All of its phones so far have had 3.5-inch screens, but the iPhone 5 has a 4-inch display, Apple CEO Tim Cook said at the event in San Francisco, according to .

That may reflect the popularity of larger devices offered by Samsung and other rivals, and it gives more real estate for apps and games. It also allows Apple to add an extra row of application icons on each page.

Despite the bigger screen, Apple said its new phone is its thinnest and lightest yet. It weighs 22 grams -- 20 percent lighter than the iPhone 4S -- and is 7.6 mm thick, or 18 percent thinner, it said.

It comes in black or white and the prices are the same as for the 4S -- US$199 for 16GB, $299 for 32GB, and $399 for 64GB, along with a 2-year carrier contract. The new phone can be ordered beginning Friday and the device will ship a week later in the U.S., U.K., Japan and other countries.

The iPhone 5 gets a speedy new chip, the A6, which marketing chief Phil Schiller said doubles the speed of both CPU and graphics operations over the A5. Operations like launching apps and viewing attachments will be twice as fast, he said.