Apple also may add finger-sensor technology to the iPhone, along with longer battery life and a speedier processor.
The iPhone maker is also releasing an overhaul of its iOS software, which will include a new music-streaming service called iTunes Radio. Invitations for the event were adorned with bubbles in the colors used in the software update, and included the greeting, "This should brighten everyone?s day."
A new iPhone 5 currently costs at least $649 in the U.S. without a subsidy from a wireless carrier, compared with about $250 for an Android device. A less expensive iPhone selling for about $300 would appeal to prepaid-market consumers, who pay for services in advance and don't opt for a subsidized phone as part of a multiyear contract.
Apple is also overhauling its mobile software for iPhones, iPads and iPod Touch devices. Apple previewed the iOS 7 in June, including changes to the e-mail, calendar and photo applications, as well as new fonts, icons and a brighter color scheme.
With the new iPhone 5C and 5S, Apple is expected to stop selling the iPhone 5, which was released last year. And it will also likely kill off the iPhone 4, which has remained surprisingly popular as a free option offered by carriers in the U.S.
And for your viewing pleasure, see the "lekaled" photos below of the iPhone 5S and the cheaper iPhone 5S (Chinese site WeiPhone):