Android smartphone users in the US grew to an even greater share in comScore's latest ranking, hitting 43.7%, while iPhone users grew slightly to 27.3%.
The comScore data, based on a survey of 30,000 smartphone users for three months ending August 31, also showed Research In Motion's share of the market drop in the prior three-month period ending May 31.
The increase in the number of Android smartphones sold by several cellphone makers, including Samsung, LG, Motorola and HTC was substantial. Android phone sales grew by 5.6%, increasing its market share to 43.7%, up from 38.1% in the prior report. That's an increase of nearly 15% in three months.
Apple's iPhone had 84.5 million owners for a market share of 27.3%, ComScore said, up from 26.6% in May, an increase of 2%.
RIM, maker of BlackBerry smartphones, saw its share decline to 19.7%, down from 24.7%, a decrease of more than 20%.
Smartphones running Windows Phone 7 saw a slight decline over the previous report, slipping from 5.8% to 5.7%.
While RIM's downward trend is steep, the smartphone maker stands to continue increasing its smartphone sales because the overall smartphone market is growing dramatically, with 10% more smartphone users seen by comScore at the end of August as compared with the end of May.
Meanwhile, the top five smartphone manufacturers saw modest changes over the three months between the two reports. Samsung stayed on top with 25.3% of mobile phone subscribers, a 0.5% increase; LG slightly declined to 21.0%, down from 21.1%. Motorola also declined to 14%, down from 15.1%. Apple improved to 9.8%, up from 8.7%, while RIM declined to 7.1% from 8.1%.