Smartphones bearing Google's Android operating system surpassed Apple iOS in the U.S., grabbing 26 percent to Apple's 25 percent share through the three-months ending in November 2010.
ComScore found that Android now places in the No. 2 slot, behind market leader RIM's Blackberry OS share, which slipped to 33.5 percent from 35.8 percent through October. Blackberry, whose share was 37.6 percent in August, continues to see declining share at the hands of Android and iOS.
Microsoft's Windows platform share also dropped 1.8 percent to 9 percent through November, as Windows Phone 7 devices try to gain traction.
While Apple grew share to 25 percent from 24.6 percent through October, it may have the greatest cause for concern here. Android's share had yet to crack 19.6 percent through August, while iOS commanded 24.2 percent share at that time.
ComScore's new numbers show Android gained 6 percentage points of share since the end of the summer, while iOS grew less than 1 percent, no doubt on the strength of a strong iPhone 4 offering.
While Apple was absent from the 2011 Consumer Electronics Show, Google's Android operating system drew strong interest, thanks to 4G smartphone announcements from Motorola and Samsung.
These rivals will ship devices powered by Verizon Wireless' speedy new broadband network later this year.
Android's swift rise and iPhone's modest growth make the iPhone launch on Verizon Wireless all the more crucial for Apple, which is expected to do just that this quarter. Expect an additional iPhone refresh this summer to challenge Android handsets.
Samsung meanwhile enjoyed 24.5 percent of U.S. mobile subscribers. LG ranked second with 20.9 percent share, followed by Motorola at 17.0 percent, RIM at 8.8 percent and Nokia at 7.2 percent.
Overall, 61.5 million people in the U.S. owned smartphones during the three months ending in November, up 10 percent from the prior three-month period.
The pie continues to grow larger for phone makers, which are jockeying for greater pieces of it.