Worldwide sales of smartphones grew by over 40% year-on-year in the second quarter of 2012, according to analyst firm Gartner.

However, overall sales of mobile phones fell 2.3% in the quarter as consumers held out for forthcoming devices, it said.

"Demand slowed further in the second quarter of 2012," said Anshul Gupta, principal research analyst at Gartner. "The challenging economic environment and users postponing upgrades to take advantage of high-profile device launches and promotions available later in the year slowed demand across markets. Demand of feature phones continued to decline, significantly weakening the overall mobile phone market.”

Samsung sold the most devices worldwide in the second quarter, capturing 21.6% of the market share. Sales were boosted by its Galaxy range, including its S3 flagship model, which accounted for 50.4% of all Samsung mobile devices.

Google’s Android extended its lead as the most popular OS, with an increase of 20.7% in market share in the second quarter.

Consumer demand for Apple’s iPhone weakened as sales fell 12.6% quarter on quarter, but grew 47.4% year on year. Apple’s iOS saw its share grow 0.6% year over year but declined 3.7% quarter on quarter, and Gartner predicts that the Cupertino-based company could experience a weak third quarter depending on the timing the iPhone 5 launch.

"Samsung and Apple continued to dominate the smartphone market, together taking about half the market share, and widening the gap to other manufacturers. No other smartphone vendors had share close to 10 percent," Anshul said.

"In the race to be top smartphone manufacturer in 2012, Samsung has consistently increased its lead over Apple, and its open OS market share increased to one-and-a-half times that of Apple in the second quarter of 2012,” he said.

Sales of Nokia phones declined 14.8% in the second quarter as it battled to maintain its position in the feature phone market. Its position was worsened in the smartphone market due to its struggling Lumia handset range.

"Declining smartphone sales is worsening Nokia’s overall position, as it had already lost the No. 1 position to Samsung in the previous quarter and is facing reduced profitability due to continuous declining sales of premium smartphones," said Gupta.