Though still fourth among the top five mobile-phone players, Apple outshone its global rivals in the second quarter with skyrocketing shipment growth and a surge in market share, according to a new IDC report.

Released yesterday, IDC's report found that Apple shipped 20.3 million iPhones in the quarter, a leap of 142 percent from the 8.4 million shipped in the prior year's quarter. Among the top five vendors, Apple also saw the biggest jump in market share, capturing 5.6 percent of global mobile-phone shipments, compared with 2.6 percent a year ago.

Apple

Apple's growth rate rose despite the age of its iPhone 4, now more than a year old. The company is expected to release an update to its flagship phone sometime this fall, with many sources pointing to a September launch date. Despite its global success, some of Apple's future smartphone growth will depend on its ability to generate more business in developing markets, IDC noted.

Industry leader Nokia held onto its No. 1 slot, but its market share continued to plummet, sinking to 24.2 percent in the second quarter from 33.8 percent a year ago. Excess inventory in regions like China and Europe apparently triggered a drop in shipments. Stung by the iPhone and Android phones, Nokia recently reported a huge loss for the second quarter.

Over the long haul, Nokia's ability to bounce back will depend on its recent partnership with Microsoft and its ability to successfully move from Symbian to Windows Phone as its core mobile OS. The company's first smartphones running Windows Phone 7 are expected to reach consumers later this year.

In second place, Samsung saw an increase in shipments, though its market share remained flat. Like other vendors, the company was hit by lower demand for its feature phones. But it grabbed customers with its popular Galaxy smartphone lineup, particularly the Galaxy S II, which sold more than 5 million units in the three months following its debut.

Looking just at smartphones rather than at all mobile phones like IDC's report does, Samsung overtook Nokia in sales for the second quarter and may have outpaced Apple as well, according to Strategy Analytics analyst Neil Mawston.

Third-place LG saw a decline in both shipments and market share. The company downgraded its outlook for the year based on lower sales of feature phones, fewer new smartphone releases, and overall competition.

Finally, China's ZTE scored fifth place among the top vendors, increasing both shipments and market share. Although the company has typically been known for its simpler mobile phones, it has stepped up its smartphone game with such Android phones as the Blade and Racer.

Overall, the global mobile-phone market grew by 11.3 percent in the quarter as vendors shipped 365.4 million units, up from 328.4 million a year ago. Growth was actually less than IDC had forecast as a result of a 4 percent drop in shipments for feature phones, their first decline since the third quarter of 2009 and a sign of the ongoing shift to smartphones.

"For the overall market to grow by double digits year over year, despite the decline in feature phones, is testament to the strength of the global smartphone market," Ramon Llamas, an IDC senior research analyst said in a statement. "While this is not a new trend--smartphones have been the primary engine of growth for the last several quarters--it does mark something of a transition point, as demonstrated by the growing number and variety of smartphones featured in the vendors' portfolios."