ComScore's survey of 30,000 users found that Android's market share grew by 15% compared to its February survey results. That survey found that 33% of all smartphone subscribers used Android.

The popularity of Apple's iPhone also grew in the latest survey, as its U.S. market share increased from 25.2% share in February to 26.6% share in May, a 5% hike, ComScore said.

The shares of all the other major platforms declined over the period.

For instance, Research in Motion's share of the smartphone market dropped to 24.7% share from 28.9% in the earlier report. The decline let Apple take over second place in the survey.

Microsoft's held 5.8% of the market in the latest survey, down from 7.7% in the February report. Palm's share declined from 2.8% to 2.4%, ComScore said.