Demand for the top-end iPhone 5S was higher than Apple first anticipated, leading the tech giant to slash production of the cheaper iPhone 5C and push its flagship device harder at retail.
Speaking after Apple revealed record quarterly sales of 51 million iPhones, CEO Tim Cook told investors that the sheer size of demand for its top-of-the-range edition caught the company off guard.
He said that in response it had to manufacture more units of the 5S, meaning sales were potentially lost while customers were made to wait.
“It took us some time in order to build the mix that customers were demanding. As a result, we lost some units for part of the quarter in North America,” he added.
Apple refused to reveal exactly how many iPhone 5C units it sold. However, reports have suggested that the iPhone 5S has been outselling the cheaper device by as much as two to one.
Recent rumours have suggested that Apple may do away with the lower-cost model when it rejigs its iPhone line-up later this year.