Research In Motion (RIM) and Motorola remain on top in the U.S. mobile phone market. Based on data between November and February, comScore found Motorola to be the top handset manufacturer overall with 22.3 percent market share, while RIM led among smartphone platforms with 42.1 percent market share.

comScore found that in the three-month average ending in February, 234 million Americans age 13 and older were mobile subscribers, with device manufacturer Motorola ranking as the top OEM. LG ranked second with 21.7 percent share, followed by Samsung at 21.4 percent share, Nokia at 8.7 percent share and RIM at 8.2 percent share.

According to the report, 45.4 million people in the United States owned smartphones in an average month during the December to February period, up 21 percent from the three months ending November 2009. RIM rose 1.3 percentage points versus the prior period.

Apple ranked second with 25.4 percent share followed by Microsoft at 15.1 percent, Google at 9 percent, and Palm at 5.4 percent. Google’s Android platform continues to see rapid gains in market share as more Android-compatible devices are introduced to the market.

Test messaging continued to grow as a service. In an average month, 64 percent of U.S. mobile subscribers used text messaging on their mobile device. That’s up 1.9 percent versus three months prior. Browsers were used by 29.4 percent of U.S. mobile subscribers, while subscribers who used downloaded applications made up 27.5 percent. Accessing social networking sites or blogs continued to grow, increasing 2.9 percentage points to 18.0 percent of mobile subscribers.