Google's Android operating system captured the top spot among smartphone platforms for the first time in January, followed by RIM and Apple, says a report from comScore.

Android handsets accounted for 31.2 percent market share in the United States for the three month average period ending January, after two short months in second place. comScore said Android's market share grew 7.7 percent from October 2010 through January.

RIM held the second position with 30.4 percent market share, down 5.4 percent. Apple with 24.7 percent market share was nearly flat at 0.1 percent growth. Microsoft saw its share falling to 8.0 percent from 9.7 percent, while Palm share declined to 3.2 percent from 3.9 percent.

The report, which surveyed more than 30,000 U.S. mobile subscribers, found Samsung to be the top handset manufacturer overall with 24.9 percent market share. LG ranked second with 20.8 percent share, followed by Motorola (16.5 percent), RIM (8.6 percent) and Apple (7.0 percent).

About 66 million people in the U.S. owned smartphones during the three months ending in January 2011, up 8 percent from the preceding three-month period, comScore said.

A data released by the Nielsen Co. also showed that Android (29 percent) appears to be pulling ahead of RIM Blackberry (27 percent) and Apple iOS (27 percent) when it comes to consumer marketshare by operating system. Nielsen measured smartphone operating system market share from November 2010 to January 2011.