Apple Inc sold the most number of smartphones globally in the fourth quarter, overtaking Samsung Electronics Co Ltd (005930.KS) for the first time since 2011, according to research firm Gartner.

Apple sold 74.83 million smartphones to end users worldwide, ahead of the 73.03 million phones sold by Samsung, according to Gartner's report.

The success of big-screen iPhone 6 and 6 Plus drove Apple's sales in its first quarter ended Dec. 27. The company reported a profit of $18 billion for the period, the biggest ever reported by a public company, according to S&P analyst Howard Silverblatt.

Apple's smartphones sales jumped about 49 percent in the fourth quarter, according to Gartner. In contrast, Samsung, the market dominator since 2011, recorded a nearly 12 percent fall.

In January, the company posted its fifth consecutive quarter of earnings decline in the mobile division.

"Samsung continues to struggle to control its falling smartphone share, which was at its highest in the third quarter of 2013," said Anshul Gupta, principal research analyst at Gartner.

Besides losing market share to the costlier iPhones, the Korean company has been battling low-cost Chinese vendors such as Xiaomi and Huawei (002502.SZ).

Samsung unveiled its new range of slim-bodied Galaxy S smartphones on Monday, made from aircraft-grade metal.