Apple is going to launch an iPhone trade-in program aimed at encouraging customers to upgrade to the iPhone 5 and refurbishing used phones for sale in emerging markets, Bloomberg reports.

Sources claim Apple has joined forces with Brightstar Corp. The plan, according to Bloomberg's sources, will be to let iPhone 4 or 4S owners exchange their devices for cash toward an iPhone 5 on-site. AT&T already offers up to $200 for operating iPhone 4 and 4S.

Trade-in programs like this help to supports sales of new products in mature markets like the U.S. and foster business elsewhere. A trade-in program would not only help Apple break into developing markets, but it would also retain the company's customer base.

A report released last October -- one month after the iPhone 5 was released -- said iPhone user loyalty was declining.