By Josh Ong

Published: 11:50 PM EST (08:50 PM PST)

Record sales of the iPhone pushed Apple past ZTE and LG to become the third-largest handset vendor in the world, according to a new analysis from IDC.

The market intelligence firm released its Worldwide Mobile Phone Tracker results for the December quarter on Wednesday, noting a 6.1 percent increase in the market from a year ago. IDC estimated worldwide shipments of 427.4 million shipments during the period surpassed the research group's expectations of 4.4 percent growth for the quarter.

The growth was, however, significantly lower than the third quarter of 2011, which saw 9.3 percent growth. IDC senior research analyst Kevin Restivo called the figures "unusually low" and cited "weaker macroeconomic conditions" around the world. The analyst did point out that Apple's launch of the iPhone 4S played a key part in the market's growth last quarter.

"The introduction of high-growth products such as the iPhone 4S, which shipped in the fourth quarter, bolstered smartphone growth. Yet overall market growth fell to its lowest point since 3Q09 when the global economic recession was in full bloom," Restivo said.

IDC placed Nokia at the top of mobile phone vendors with estimated shipments of 113.5 million units during the fourth quarter of 2011, down 8.2 percent from a year ago. South Korea's Samsung came in second with estimated shipments of 97.6 million units, up 20.9 percent year over year. Apple posted an impressive 128.4 percent growth with shipments of 37 million iPhones, giving it an 8.7 percent share of the market.



Rounding out the top five, LG saw shipments erode from 30.6 million units in the fourth quarter of 2010 to 17.7 million phones in the most recent quarter, while Chinese handset maker ZTE had 17.1 million.

For all of the top five handset vendors except Apple, feature phones represented the majority of mobile phone shipments. But, feature phones sales are expected to decline. Senior research analyst Ramon Llamas noted that the low-cost handsets are "fighting to maintain their market share." According to him, handset makers are adding features like mobile Internet and third-party applications to their feature phones in order to slow the decline.

IDC's results are roughly in line with the numbers Strategy Analytics released last week, though IDC's estimates put worldwide quarterly sales at 427.4 million compared to Strategy Analytics' estimate of 445 million. As a result, IDC assigns a larger market share (8.7 percent) to Apple, which releases its numbers publicly. Apple was also pronounced the No. 1 smartphone maker by Strategy Analytics last week, with Samsung narrowly coming in second with estimates of 36.5 million units shipped.

The December quarter was Apple's most profitable quarter ever with record sales of iPhones, iPads and Macs. “Apple’s momentum is incredibly strong, and we have some amazing new products in the pipeline,” said CEO Tim Cook.