Apple is expected to ship 41-43 million iPhone devices in the second quarter of 2016 (or Apple's fiscal third quarter) before ramping up shipments to 45-48 millionin the third quarter, according to the latest estimate of Digitimes Research, which made the assessment based on Apple's recently released financial reports and related information provided by sources from Taiwan's handset supply chain.

Apple saw shipments of its iPhone products slide 16.5% to 51.19 million units in the first quarter of 2016, which met market expectations. However, Apple's projection for a 13.3-17.3% on year decline in second-quarter revenues to US$41-43 billion will mean continued decline of iPhone shipments in the quarter, Digitimes Research said.

For all of 2016, total shipments of iPhone devices are expected to reach 210-220 million units, decreasing 4.9-9.2% from a year earlier, Digitimes Research added.

Based on Apple's financial reports, the sell-through rate of iPhone devices declined less than 5% on year in the fourth quarter of 2015, but the ratio dropped to14% on year in the first quarter of 2016, indicating a significant decline of sales momentum for iPhones in the quarter.

However, Apple has been ramping pull-in orders for low-priced iPhone 5s and iPhone SE in the first half of 2016, while lowering the orders for iPhone 6s and iPhone 6s Plus, Digitimes Research revealed.

Total production of iPhone 5s is expected to reach 12-13 million units in the first half of 2016. Additionally, Apple is also set to increase orders for iPhone SE in the second and third quarters of 2016.

While ramping up shipments of iPhone 5s and iPhone SE will make up decreasing sales of iPhone 6s devices, the practice will also bring significant losses in ASP and gross margin for Apple, Digitimes Research commented.

Combined shipments of iPhone 5s and SE will account for 25% of total iPhone device shipments in the second quarter of 2016, pushing iPhone's ASP to US$600 in the quarter, down from US$641.8 of a quarter earlier and US$690.5 of the fourth quarter of 2015, estimated Digitimes Research.