Samsung Electronics Co., the world's largest smartphone maker, dethroned Apple Inc. as the most profitable phone maker by posting the biggest operating income during the second quarter, also becoming the sector's most profitable vendor, industry data showed on Monday.

According to the latest data by Strategy Analytics, Samsung became the world's most profitable handset vendor in the second quarter of the year with US$5.2 billion in operating profit for its handset division.

Apple, on the other hand, slipped into second place with an operating profit of $4.6 billion, the data showed.

"Apple's profit margin for its handset division has been fading recently due to lackluster iPhone 5 volumes and tougher competition from rivals. Samsung is performing well in the US market, while Huawei, ZTE and other local brands are growing vigorously in China.," the research firm said.

Apple is now under intense pressure to launch more iPhone models at cheaper price-points or with larger screens to fend off the surging competition and recapture lost profits in the second half of 2013, it said.

Earlier data by Strategy Analytics also showed that Samsung Electronics posted record sales in the second quarter of the year by shipping 76 million smartphones, compared with 69.4 million the previous quarter.

The South Korean smartphone maker also continued to dominate the global smartphone market in terms of market share, with its stake in the April-June period standing at 33.1 percent, remaining flat from the previous quarter, according to the researcher.

The second-quarter market share, however, was slightly down from its record high of 33.9 percent in the third quarter of last year. (Yonhap News)