Pegatron gearing up to build 15M iPhone 5s for Apple?

Starting off the post-holiday work week with an interesting bit of iPhone 5 speculation, device manufacturer Pegatron has reportedly received orders to build 15 million iPhone 5s from Apple, according to the Taiwanese news site Digitimes.

Citing component maker sources, Digitimes says that Pegatron is building the iPhone 5s in preparation for shipment in September. But unlike other persistent iPhone 5 rumors, Digitimes maintains that the iPhone 5 won’t be a major update over the iPhone 4.

Pegatron last year upgraded its equipment, factories and worker numbers to handle iPhone 4 orders, Digitimes points out. The company had the capacity to build 10 million CDMA-compatible iPhone 4s (the Verizon iPhone), but lower than expected sales led to it shipping less than 4 million units in the last quarter. Pegatron is also vying against other manufacturers to build iPads and MacBooks for Apple.

Digitimes uses the “iPhone 4S” moniker interchangeably with “iPhone 5,” even though they generally refer to two very different possibilities. Among rumor mongers the iPhone 4S is considered a slightly revamped iPhone 4 (similar to the iPhone 3GS from two years ago), while the iPhone 5 is thought to be a more substantial upgrade. Currently, most rumors point to Apple releasing an iPhone 5 later this year — though one curious rumor from last week pointed to Apple releasing both an iPhone 4S and iPhone 5 this year.