The Android operating system (OS) continued to shake up the U.S. mobile phone market in the first quarter (Q1) of 2010, moving past Apple to take the number-two position among smartphone operating systems, according to The NPD Group.

NPD’s wireless market research reveals that based on unit sales to consumers last quarter the Android operating system moved into second position at 28 percent behind RIM’s OS (36 percent) and ahead of Apple’s OS (21 percent).

Strong sales of the Droid, Droid Eris, and Blackberry Curve via these promotions helped keep Verizon Wireless’s smartphone sales on par with AT&T in Q1. According to NPD’s Mobile Phone Track, smartphone sales at AT&T comprised nearly a third of the entire smartphone market (32 percent), followed by Verizon Wireless (30 percent), T-Mobile (17 percent) and Sprint (15 percent).

The continued popularity of messaging phones and smartphones resulted in slightly higher prices for all mobile phones, despite an overall drop in the number of mobile phones purchased in the first quarter. The average selling price for all mobile phones in Q1 reached $88, which is a 5 percent increase from Q1 2009. Smartphone unit prices, by comparison, averaged $151 in Q1 2010, which is a 3 percent decrease over the previous year.

Methodology: The NPD Group compiles and analyzes mobile device sales data based on more than 150,000 completed online consumer research surveys each month. Surveys are based on a nationally balanced and demographically-representative sample, and results are projected to represent the entire population of U.S. consumers. Note: Sales figures do not include corporate/enterprise mobile phone sales.