ComScore (, a company that “measures the digital world,” has released data from the comScore MobiLens service, reporting key trends in the U.S. mobile phone industry during the three-month average period ending December 2010. The report shows Apple’s share of the smartphone market rising from 21.4% to 25%.

The comScore report ranked the leading mobile original equipment manufacturers (OEMs) and smartphone operating system (OS) platforms in the U.S. according to their share of current mobile subscribers ages 13 and older, and reviewed the most popular activities and content accessed via the subscriber’s primary mobile phone.

The December report found RIM to be the top smartphone market for the three-month period with 37.3% market share. That’s down from 31.6% for the three-month period ending in September 2010.

Google’s market share rose from 21.4% to 28.7% for the three-month period ending in December. That allowed it to slip ahead of Apple. Rounding out the top five were Microsoft (8.4%, down from 9.9%) and Palm (3.7%, down from 4.2%).

— Dennis Sellers