Research firm Gartner is reporting  that global cell phone sales for the second quarter of 2010 totalled 325.6 million units, an increase of 13.8 percent when compared with the second quarter of 2009. Smartphones accounted for 19 percent of phones shipped, which is a 50.5 percent increase over last year, according to the company.

Gartner also published its worldwide cell phone market share rankings for Q2, 2010. The most interesting change is the addition of smartphone maker HTC to the list, where it debuts at position number 8 after posting growth of 139.1 percent in volume over Q2, 2009.

Nokia maintains the number one position with 34.2 percent share. Samsung is number 2 with 20.1 percent share, followed by LG (9.0 percent), RIM (2.3 percent), Sony Ericsson (3.4 percent), Motorola (2.8 percent), Apple (2.7 percent), HTC (1.8 percent), ZTE (1.7 percent), and G’Five (1.6 percent).

Of the top ten manufacturers, only Samsung, RIM, HTC, and ZTE showed growth in market share compared with the second quarter of last year.

In terms of smartphone OS market share, Symbian still holds the top spot with 41.2 percent (25.4 million devices). BlackBerry OS holds 18.2 percent share, Android 17.2 percent, Apple iOS 14.2 percent, and Microsoft’s Windows Mobile slides to 5 percent from the 9.3 percent it held this time last year.

While it still maintains the top spot, Symbian’s market share fell a significant 10 percentage points, even though it sold over 4.5 million more devices this quarter than in Q2, 2009. BlackBerry OS dropped slightly from last year, while Android’s share grew 9.5 times over the the 1.8 percent it held last year. Apple’s iOS gained slightly.