Worldwide sales of mobile devices totalled 428.7 million units in the second quarter of 2011, a 16.5 percent increase from the second quarter of 2010, according to research firm Gartner Inc.Sales of smartphones were up 74 percent year-on-year and accounted for 25 percent of overall sales in the second quarter of 2011, up from 17 percent in the second quarter of 2010. Gartner said it expects sales of mobile devices to grow around 12 percent in 2011. \"Smartphone sales continued to rise at the expense of feature phones,\" said Roberta Cozza, principal research analyst at Gartner. \"Consumers in mature markets are choosing entry-level and midrange Android smartphones over feature phones, partly due to carriers\' and manufacturers\' promotions.\" However, replacement sales in Western Europe showed signs of fatigue as smartphone sales declined quarter-on-quarter. Nokia\'s smartphone sales in the second quarter of 2011 were low, partly due to a very competitive market that deflated demand for operating system Symbian, but also to inventory management issues in Europe and China in particular.These factors reduced Nokia\'s average selling price for smartphones, compared to the first quarter of 2011 but it remained the leading smartphone manufacturer by volume, Gartner said. Samsung achieved strong growth in sales of mobile devices, with the Galaxy S II selling well, chalking up 5 million sales by the end of July.A strong performance in the smartphone market helped Samsung increase its market share, to become the third-largest smartphone vendor. Apple continued to exceed expectations, even though the iPhone 4 will soon be replaced by a new model. Part of its growth came from the 42 new carriers and 15 new countries that it entered in the second quarter of 2011, which brought its total coverage to 100 countries. Research In Motion\'s (RIM\'s) share of the smartphone market declined to 12 percent in the second quarter of 2011, from 19 percent a year ago. The company also lost its No. 5 position in the worldwide ranking of mobile device vendors to ZTE.\"We expect manufacturers and distributors to remain cautious about raising their stock levels in the second half of 2011, following the recent uncertainty on the world financial markets,\" said Annette Zimmermann, principal research analyst at Gartner. From / Arabian Business News