While Pegatron Technology has become an OEM for the iPhone 6s and is seeing increasing revenues, three of its subsidiaries - metal-alloy chassis maker Casetek Holdings, IC substrate maker Kinsus Interconnect Technology and own-brand motherboard maker ASRock - are not performing as expected in terms of profitability, according to industry sources.

Pegatron, which has landed orders for the 4.7-inch iPhone 6s, has been aggressively expanding its capacity and is currently able to oroll out 10 million units a month.

Compared to Foxconn Electronics (Hon Hai Precision Industry), who sees orders from Apple benefiting its component subsidiaries such as Zhen Ding, General Interface Solution (GIS) and Foxconn Technology, Pegatron's orders from Apple have not been much help for Casetek and Kinsus.

With orders for mid-range and entry-level handsets from China weaker than expected, investments in the printed circuit board (PCB) business suffering losses and competition from Japan-based Ibiden for iPhone 6 orders becoming fiercer, Kinsus' EPS may drop below NT$6 (US$0.18), weaker than the NT$8 in 2014.

ASRock has also not been performing well in the face of pricing competition from Asustek Computer and Gigabyte Technology. The Pegatron subsidiary is now looking to gain profits from server and industrial PC (IPC) motherboards, but so far the business has not made any major contribution and ASRock's EPS for 2015 may be more than halved.

Although Pegatron has also entered the market for contact lenses and optical products, profitability from the market is unlikely to see major growth because of fierce price competition.