Research firm comScore is out today with its usual report covering U.S. smartphone subscriber market share for the three month period ending in May. Over the last three months Apple has gained in both categories including ‘top smartphone OEMs’ and ‘OS usage’, continuing its lead as the top smartphone manufacturer and growing its share of the market by platform.

The previous three month period had Apple at 38.9% of the market, making it the number #1 smartphone vendor in the US over second place Samsung. In May, Apple continues that lead by increasing its share 0.3 percentage points to 39.2% of the market. That’s significantly higher than the 23% Samsung grabbed despite growing 1.7 percentage points during the quarter. In a close race for third place is HTC with 8.7%, Motorola with 7.8%, and LG with 6.7%, all of which dropped less than a percentage point since last quarter.

When it comes to the market by OS usage, Android is still on top, growing 0.7 percentage points to 52.4% this quarter. Apple experienced slightly less growth at 0.3 percentage points to capture 39.2% of the market up from its 38.9% share last quarter. That means the majority of the growth, once again, comes at the expense of BlackBerry and Microsoft.

BlackBerry once again lost some share to Android and Apple (not surprising considering its recent earnings release), falling 0.6 percentage points to 4.8% of the market.

Microsoft too was down this quarter grabbing a minuscule 3.0% of the market by platform, but was still above last place Symbian at 0.4%.