Apple, Google and RIM are growing their shares of the US smartphone operating system market, while Microsoft and Palm decline. The comScore data for the three-month average ending this January also shows Motorola maintaining its lead as top mobile handset manufacturer.

The January comScore report found Motorola to be the top handset manufacturer overall with 22.9 percent market share, while RIM led among smartphone platforms with 43.0 percent market share. Google's Android smartphone platform continues to see rapid gains in market share.

According to the data 42.7 million people in the US owned smartphones in an average month during the November 2009 to January 2010 period - up 18 percent from the August through October 2009 period.

BlackBerry Bold 9700 smartphone

BlackBerry was the leading mobile smartphone OS platform in the US with 43 percent share of smartphone subscribers - up 1.7 percentage points versus three months earlier.

Apple's iPhone OS platform ranked second with 25.1 percent share (up 0.3 percentage points), followed by Microsoft at 15.7 percent (down 4), Google's Android at 7.1 percent (up 4.3), and Palm at 5.7 percent (down 2.1).

The data is taken from the comScore MobiLens service, reporting key trends in the US mobile phone industry during the three month period between October 2009 and January 2010. The report ranked the leading mobile original equipment manufacturers (OEMs) and smartphone operating system (OS) platforms according to their share of current mobile subscribers age 13 and older, as well as popular activities and content accessed via the subscriber's primary mobile phone.

In the same period 234 million Americans were mobile subscribers aged 13 and older, with device manufacturer Motorola ranking as the top OEM with 22.9 percent of US mobile subscribers. LG ranked second with 21.7 percent share, followed by Samsung (21.1 percent share), Nokia (9.1 percent share) and RIM (7.8 percent share).

BlackBerry maker RIM was the only handset maker registering a significant rise (up 1.4 percentage points).

comScore reported that 63.5 percent of US mobile subscribers used text messaging on their mobile device, up 1.5 percent versus three months prior.

Browsers were used by 28.6 percent of US mobile subscribers (up 1.8 percent), while subscribers who played games made up 21.7 percent (up 0.4 percent).

Access of social networking sites or blogs experienced strong gains in the past three months, growing 3.3 percentage points to 17.1 percent of mobile subscribers.