April means lots of new first-quarter market share numbers. And research firms are stepping over each other to show that Samsung is faring well vis-a-vis its nemesis Apple -- which isn't doing too badly itself, though.

ComScore said today that Samsung is the top handset supplier among the 30,000 mobile subscribers surveyed in the U.S., with a 26 percent share in the three-month period ending in March. (see chart below).

In that period, 234 million Americans age 13 and older used mobile devices, according to ComScore.

LG was No. 2 with 19.3 percent and Apple third with 14 percent.

But, among the top five, Apple recorded the largest gain -- 1.6 percentage points -- in the March period over the three-month period ending in December 2011.

Samsung was up 0.7 percentage points, LG was down 0.7 percent. In overall market share, LG was followed by Motorola, at 12.8 percent, and HTC with 6.0 percent.

Looking at smartphones only, more than 106 million people in the U.S. owned smartphones during the three month period, up 9 percent compared with December, ComScore said.

Google's Android was the top smartphone operating system with a 51 percent market share (up 3.7 percentage points). Apple's share of the smartphone market was up 1.1 percentage points to 30.7 percent. RIM was a distant third with a 12.3 percent share: its share dropped 3.7 percent. Microsoft's share was 3.9 percent and Symbian, 1.4 percent.

In March, 74.3 percent of U.S. mobile subscribers did text messaging, 50 percent download apps, and accessing social networking sites or blogs increased 0.8 percentage points to 36.1 percent of mobile subscribers.