Samsung Electronics has forecast weaker-than-expected profits for the April to June quarter.
The world's biggest mobile phone and TV maker has estimated an operating profit of 9.5 trillion won, 8.3 billion dollars, for the quarter.
According to the BBC, most analysts had expected a figure closer to 10.1 trillion won.
The success of Samsung's smartphones has been key the company's recent growth. However, there have been concerns that its growth rate may be slowing despite the launch of new models.
Samsung shares fell 3.8 percent after the profit guidance. Its shares have dropped more than 15 percent since early June, the report said.
Research firm Strategy Analytics said Samsung accounts for almost 95 percent of the Android smartphone sector's profits.
Despite all that success, there have been concerns in recent weeks that the rate of growth that Samsung's smartphones have enjoyed in recent years may be slowing, a trend that may eventually hurt profits.
The concerns have been triggered in part by the launch of new products from rival manufacturers as well as relatively low-cost smartphones by Chinese firms, the report added.