While the company has predicted record sales for its most recent quarter, Apple has been facing increased competition from rival smartphone makers, such as Samsung, Nokia(NOK), HTC and LG.
In October, Apple reported mixed results for its fiscal fourth quarter, saying it sold just shy of 27 million iPhones, up 58% from a year earlier. At the time, Apple was having trouble keeping up with demand for the iPhone 5.
Apple will release its fiscal first-quarter results on Jan. 23. Analysts surveyed by Thomson Reuters expect earnings to decline 4% from the prior year, although estimates vary widely.
Apple has not reported a drop in quarterly earnings in nine years.