Following Apple's decline, Foxconn reports first sales dip in 25 years

Foxconn's 2016 revenues were $136.38 billion, 2.81 percent lower than in 2015, according to Nikkei. Apple accounts for over 50 percent of Foxconn's revenue, closely linking the two companies.

While Apple tried to put a positive spin on the situation, last year it posted its first annual sales decline since 2001, something directly related to lower iPhone sales. The latter problem was regularly blamed on lukewarm demand for the iPhone 6s.

Slowing sales even led Apple to issue a pay cut for its executive team, including CEO Tim Cook, whose compensation was docked by $1.5 million for failure to meet the company's internal goals.

While the 6s introduced improvements like Live Photos, 4K video recording, and 3D Touch when it launched in Sept. 2015, it was generally seen as a modest upgrade from the iPhone 6 and a tough sell both for existing iPhone owners and people considering high-end Android phones.

Foxconn's Dec. 2016 revenues did grow 9.76 percent year-over-year however, which Nikkei tied to "relatively robust demand" for the iPhone 7 Plus. The Plus has a dual-lens camera, which not only magnifies images but enables a special Portrait mode with simulated, DSLR-like bokeh (blurred backgrounds).

Nikkei previously reported that Apple was cutting iPhone 7 orders by 10 percent for 2017, despite allegedly not being able to keep up with 7 Plus demand. That claim could be explained by Pegatron's December figures — the supplier, which assembles the standard iPhone 7, saw its revenues plummet 27.43 percent year-over-year.