Samsung Electronics Co. on Friday said that its operating profit in the three months that ended in December was 5.2 trillion won ($4.5 billion). Compared with 3.01 trillion won a year ago, the fourth-quarter profit beat analysts' estimates.

The major catalyst for this is the increased phone sales masked declining earnings in its chips and panel businesses. According to Bloomberg the South Korean company’s mobile-phone sales has gone past  300 million units last year as the Galaxy smartphones helped win consumers amid competition with Apple Inc.'s iPhone.

Operating profit at the telecommunications unit jumped 81 percent to 2.6 trillion won, according to the median of six analyst estimates surveyed by Bloomberg News. Sales at the world's second-largest handset vendor may have gained 36 percent to 16.45 trillion won.

Samsung probably sold about 32 million smartphones in the fourth quarter, according to an estimate from Dongbu Securities Co., helped by the Galaxy range of devices. The Galaxy S II sales, which began in May, surpassed 10 million units quicker than any other Samsung mobile device, the company said in a December statement, without providing a total sales figure for the model.

Samsung sold more than 300 million handsets, including basic types, in 2011, according to the statement.

In October, Samsung and software partner Google Inc. unveiled the Galaxy Nexus, powered by the latest Android operating system that features facial-recognition functions. A month earlier, Samsung introduced the Galaxy Note equipped with a 5.3-inch screen and a stylus.