Android is leading the smartphone market, with Apple in second and BlackBerry maker Research in Motion eating dust at a distant third, according to a new report by research firm ComScore.

76.8 million people in the U.S. owned smartphones during the three months ending in May 2011, up 11 percent from the preceding three month period, according to the research firm. Google Android ranked as the top operating system with 38.1 percent of U.S. smartphone subscribers, up 5.1 percentage points. Apple strengthened its #2 position with 26.6 percent of the smartphone market, up 1.4 percentage points. RIM ranked third with 24.7 percent share, followed by Microsoft (5.8 percent) and Palm (2.4 percent).

In addition, for the three month average period ending in May, 234 million Americans ages 13 and older used mobile devices. Device manufacturer Samsung ranked as the top OEM with 24.8 percent of U.S. mobile subscribers, followed by LG with 21.1 percent share and Motorola with 15.1 percent share. Apple strengthened its position at #4 with 8.7 percent share of mobile subscribers (up 1.2 percentage points), while RIM rounded out the top five with 8.1 percent share.