San Francisco, Sep 13 (IANS): Apple's much awaited next-generation iPhone is finally here. The iPhone5 sports a larger four-inch screen that is 18 percent thinner and 20 percent lighter than its predecessor.

Said to be a bit more thumb-friendly, iPhone 5 with 16:9 aspect ratio was unveiled by Apple chief executive Timothy D. Cook Wednesday at the Yerba Buena Centre for the Arts in San Francisco.

"It's an amazing time at Apple, an extraordinary time," said Cook as he walked on stage, wearing a black button-down shir and blue jeans somewhat like Apple's co-founder Steve Jobs who always wore his trademark black turtleneck and jeans.

Last quarter, Apple sold its 400 millionth iOS device.

"Today, we're taking it to the next level," Cook said in a room brimming with journalists as Phil Schiller, Apple's marketing chief, took the stage to explain the new iPhone's features.

The new machine has speedier innards, thanks to a new A6 chip designed by Apple. The chip is twice as fast in terms of CPU and graphics, he said. "Not only is it a jump forward in performance, it's 22 percent smaller."

The iPhone 5 has chips that support additional bands and frequencies and it's capable of delivering up to 100 Mbps per second, Schiller said announcing the carrier partners for the new iPhone: AT&T, Verizon, Sprint, Telefonica, among others.

The roomier screen of the iPhone 5, which has 40 percent more colour saturation, can be used by apps makers to provide most accurate display in the industry.

The iPhone's width is just right for navigating with one's thumb, Schiller said, to make it easy to send text messages, swipe through pages and browse the Web.

The additional vertical space on the iPhone 5 screen will let users add a fifth, additional row of apps on the home screen - more room for Web browsing and reading, he said.

Apple now has 380 stores in 12 countries. Some 83 million customers visited Apple stores in June, roughly one million per day, Cook said.