Despite a global economic slowdown that is hurting the mobile market, smartphone shipments continued to rise in the third quarter, according to a report from research firm IDC.

Thanks to popular devices like Apple's iPhone 3GS, handset makers shipped 43.3 million smartphones during the third quarter of 2009, a 4.2% year-over-year increase. IDC expects this trend to continue, and the market for smartphones will grow at a faster rate than the overall cell phone market.

Nokia remains the global leader with about 37.9% of the smartphone market. The company just released its first Linux-based smartphone, the N900, and it's ramping up its service offerings, including music, maps, navigation, and application delivery. While its global leadership is secure, Nokia continues to struggle in North America, IDC said.

Research In Motion shipped 8.2 million BlackBerry smartphones during the quarter, IDC said, which accounted for 19% of the global market. The company's enterprise base remains strong, but it is also finding success with mainstream customers or "pro-sumers." RIM is poised for the holiday season as it just updated its lineup with the Storm 2 and BlackBerry Bold 9700, but the competition is increasing. For example, last year Verizon Wireless' flagship device was the BlackBerry Storm, but this year, the carrier's weight and marketing dollars are backing the Motorola Droid.

Apple was able to up its market share and reach its highest volume of sales in a single quarter, IDC said. The company's iPhone 3GS is available in nearly every market worldwide, and Apple's market share rose to 17.1% from 16.6% last year. Apple's deal with China Unicom is expected to boost shipment volumes in the future, but the iPhone has received a tepid response in China so far.

The Google-backed Android operating system is poised to reach critical mass, IDC said. The Linux-based OS is gaining steam with high-profile releases like the Droid, and HTC, Sony Ericsson, Samsung, LG Electronics, Garmin-Asus, and Motorola have plans to release multiple Android-powered smartphones over the next few quarters.

"With an expanding portfolio of handsets and a just-released update of the code, Android is poised to mount a serious challenge to the incumbent smartphone OEMs for the first time in its brief history," said William Stofega, research manager with IDC, in a statement.

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