(Pocket-lint) - Samsung has been the largest beneficiary in the rise in popularity of Android smartphones over the years, with its Galaxy range topping the pile year-on-year. However, sales of its 2014 flagship phone, the Galaxy S5, have shown that the tide is turning.

Samsung sold four million fewer SGS5 handsets worldwide in its first three months on sale than it did the Galaxy S4 in an equivalent period. That's well below expectations - in fact, 40 per cent lower than the company originally projected.

The Wall Street Journal suggests that the poor performance and piles of unsold stock could lead to a management shake-up. Head of the company's mobile business, JK Shin, is tipped by the paper to be shifted from his position although there's no confirmation on that at present.

Numerous factors can be at fault for the Galaxy S5 under-performing. The Galaxy S4 had few competitors in its category when it was launched in 2013, while the Galaxy S5 has many more rivals of a sufficiently high quality.

READ: Samsung Galaxy S5 review

The company also put equal amount of effort into its Note range of devices, with many seeing that they have taken on the flagship mantel.

Samsung has also acknowledged that its strategy of releasing 50 or so phones a year needs to be addressed, with fewer product lines suggested.

READ: Best smartphones 2014: The best phones available to buy today

Writing by Rik Henderson.