Tablet PC shipments fell in the first quarter of 2014 for the first time, a sign that customers are turning to large-screen smartphones instead of products like the Apple iPad.

56 million tablets were shipped worldwide between January and March this year, down from 59 million one year ago, according to a new report by NPD DisplaySearch. Along with delayed launches of new products, a major reason for the decline is that the rising popularity of smartphones 5.5 inches and larger is drawing in longtime users of smaller tablets.

“Tablet PC demand in 2014 is being affected by falling demand for the 7” class in emerging regions and in China, where many local white-box brands have experienced lower-than-expected shipment growth,” NPD vice president Hisakazu Torii said in a statement.

The study forecasts that in 2014 the year-on-year growth rate of tablet PC sales — once a primary growth driver for the smart device market, especially after the iPad debuted in 2010 — will fall 14%, a revised estimate that docked NPD’s original predicted growth rate by 3%. By 2017, the rate will slow to single digits.

NPD’s findings follow Samsung’s recent announcement of its disappointing sales, in part due to large smartphones cannibalizing sales of small tablets.

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