The tech firm warned at the start of the year that its sales would slow, and now new research is out showing that has indeed come to pass.
Shipments fell more than 43 per cent to 42m at the start of the year from 75m at the end of 2015, according to research from TrendForce.
The firm has also lowered its estimates for iPhone shipments this year to 213m, a 10 per cent reduction, indicating the latest iPhone SE is unlikely to provide the usual new launch bump.
"As the budget model, iPhone SE will support Apple’s overall shipments in the second quarter before the next major iPhone release. However, iPhone SE is going to face severe price competition from Chinese branded products in its target market, which is the mid-range device segment," said analyst Avril Wu.
"This year’s iPhone SE shipments are projected to come in below 15m and they are unlikely to help turn around the weak annual shipment result for Apple.”
Apple's global market share fell from 20.9 per cent in the fourth quarter to 14.4 per cent in the first quarter of 2016 and earlier research from Gartner indicates that Apple's sales fell for the first time in history in the last quarter of 2015.
Reports suggest Apple has cut iPhone production for the second quarter in a row due to slow sales.
Total smartphone shipments declined more than 18 per cent in the first quarter of the year to 292m units compared to the previous quarter, and down 1.3 per cent year-on-year. For the first time, shipments of Chinese brand smartphones surpassed Samsung and Apple combined.