Apple's Senior Vice President of Worldwide product marketing Phil Schiller speaks about is a dual-mode world phone with a new antenna system to improve call quality during introduction of the new iPhone 4s at the company’s headquarters October 4, 2011 in Cupertino, California. – AFP Photo

NEW YORK: Apple shares dropped more than four per cent on Wall Street on Tuesday after the California gadget-maker unveiled an updated version of the iPhone but not a new model many analysts had been expecting.

Apple shares were down 4.93 per cent at $356.14 shortly after the company took the wraps off the iPhone 4S at an event at its Cupertino, California, headquarters.

The more powerful iPhone features a speedier processor, a built-in “personal assistant” that responds to voice commands and a more powerful camera.

Many analysts and Apple fans had been expecting a next-generation iPhone 5.

The iPhone 4S will be available in the United States, Australia, Canada, France, Germany, Japan and Britain on October 14 with pre-orders commencing a week earlier.

In the United States, iPhone 4S prices will start at $199 for a 16-gigabyte model and top out at $399 for a model with 64 gigabytes of memory.