Samsung is struggling in countries such as China because "they're sort of being eaten from the bottom up by regional players" including Huawei and Xiaomi, said Ben Bajaran, an analyst at Silicon Valley research firm Creative Strategies. Profit sank 27 percent to 5.3 trillion won ($4.9 billion). [...] September, Apple lacked one thing that Samsung and other phone-makers had: a supersized smartphone screen. In its earnings conference call, Samsung estimated that its worldwide smartphone sales during the quarter were between 72.2 million units and 75.1 million units, confirming analysts' forecasts that Apple has clawed back Samsung's lead if not overtaken it. Samsung's fourth quarter profit was a moderate improvement from the previous quarter's 4.2 trillion won and higher than analysts' forecasts of 4.4 trillion won, according to financial data provider FactSet. The company's fourth-quarter net income beat forecasts mainly thanks to the solid performance of its component businesses, such as memory chips and display panels.