Apple has begun letting US iPhone owners trade in their smartphones for credit toward buying new models.
The California company's trade-in program kicked off in the wake of unconfirmed reports of a September 10 event at which Apple will unveil new iPhones, with rumours ranging from a gold handset to a low-price version aimed at emerging markets.
"iPhones hold great value," Apple spokeswoman Amy Bessette said in an email reply to an AFP inquiry.
"So, Apple Retail Stores are launching a new program to assist customers who wish to bring in their previous-generation iPhone for reuse or recycling."
She would not specify how much Apple is paying for old iPhones, but they can fetch $US300 ($A338) or so depending on model at an array of websites or US consumer electronics shops that buy handsets.
The Wall Street Journal earlier this month reported that Apple had asked its Taiwan-based supplier, Hon Hai Precision, to begin shipping two new versions of the iPhone in September, including a lower-cost model.
Speculation has centred around whether Apple will shift its strategy of focusing on premium devices priced at the high-end of the market to include a lower-cost handset to appeal to people with tight budgets.
A survey by Gartner said Apple's share of the smartphone market worldwide fell to 14.2 per cent in the second quarter, while Samsung's share rose to 31.7 per cent.
Samsung has found global success with smartphones powered by Google's free Android software, which now dominates the market.
