Apple Inc unveiled a speedier iPhone on Monday, but contrary to rumor its convalescing Chief Executive Steve Jobs did not make an appearance.

The new iPhone 3GS is twice as fast as its predecessor, and features an improved digital camera and a new service that lets users locate their phones if they have been lost or stolen. The 3GS will cost $199 for 16 GB of memory, and $299 for 32 GB of memory.

The existing iPhone 3G will get an immediate price cut to $99.

Shares in Apple were off 0.6 percent to $143.83, after a 6.5 percent climb in the week leading up to the much-anticipated event. The stock was hit earlier in the day after reports that Apple planned to price its new iPhones aggressively.

Among other incremental announcements, the consumer electronics giant showed off a new 15-inch notebook with improved battery life, a $300-cheaper Mac Air -- its thinnest laptop -- and, as expected, its highly previewed Snow Leopard Mac operating system software.

Apple's new MacBook Air notebook now starts at $1,499. The company also unveiled a new 13-inch MacBook Pro starting at $1,199, and a 15-inch laptop with longer battery life, addressing a perennial consumer concern.

Apple's stock is historically volatile during the company's June developer conference. It dropped about 7 percent over the course of the conference in 2008 and about 4 percent in 2007.

Suspense and speculation had mounted in the months before Apple's annual Worldwide Developers' Conference, with hopes ranging from a cameo by Jobs -- out till the end of June on medical leave -- to revelations of a game-changing tablet computer.

Jobs, a pancreatic cancer survivor, announced his leave of absence in January by saying his health problems were more complex than previously thought.

Despite a slowing product line, worsening consumer spending and an uncertain succession plan, investors have quickly got comfortable with the idea of a Job-less Apple. Shares in the maker of the iPod and iPhone have surged 85 percent since shortly after the bombshell was dropped on January 14.

Jobs, a college dropout, co-founded Apple in 1976 with his friend Steve Wozniak in a Silicon Valley garage. After a falling-out with the board, he left the company in 1985.

Apple floundered, setting the scene for his return in 1997. The company has flourished under Jobs 2.0, rolling out the concept of a computer as a 'digital hub' along with the now-ubiquitous iPod and iPhone.

(Additional reporting by Clare Baldwin; Writing by Edwin Chan; Editing by Peter Henderson and Richard Chang)