More signs Android is taking a growing share of the operating software for smartphones in the United States. Google’s mobile OS has 43.7 percent of the U.S. market, according to August research by Internet measurement firm ComScore. The nearly 44 percent market ownership is a 5.6 percent jump from the end of May.

By comparison, Apple’s iOS is in second place, registering 27.3 percent of the market, up from 26.6 percent in the three-month period ended in May.

Only RIM’s BlackBerry OS made it into the double-digits, with 19.7 percent of the smartphone OS market. That’s a five-point drop from May. Finally, Microsoft’s Window Mobile and Windows 7 grabbed 5.7 percent of the smartphone software market, ahead of Symbian’s anemic 1.8 percent market morsel.

An August report by research firm NPD reported similar results for Android (52 percent) and iOS (29 percent), however posted weaker numbers for the also-rans. RIM had 11 percent of the market, while Windows Phone 7, Windows Mobile and HP’s WebOS had less than 5 percent of the smartphone OS market.

The ComScore report also found Android-based smartphone makers — Samsung, LG and Motorola — had 25.3 percent, 21 percent and 14 percent of smartphone subscribers, respectively. Apple’s iPhone had 9.8 percent of the U.S. market, the researchers announced.