FRAMINGHAM, MA – The worldwide mobile phone market grew 19.8% year-over-year in the first quarter of 2011, says the International Data Corp.

Fueled by high smartphone growth, especially in emerging markets, and gains made by market challengers, vendors shipped 371.8 million units during the quarter.

Smartphone growth worldwide, particularly in Asia/Pacific (excluding Japan), Middle East and Africa, and Latin America, helped lift the overall market to a new first-quarter high, says IDC. Smartphone-specific vendors, such as HTC, continue to grow sales at a steady clip as a result of this trend.

IDC expects almost all of the worldwide mobile phone market's growth to be driven by smartphones throughout the forecast, through 2015.

“The growth of companies outside the top 5 vendors – vendors in the “others” category, such as Micromax, TCL-Alcatel, Huawei, and Research In Motion – shows that the overall market is still very much ripe for share gains,” said Kevin Restivo, senior research analyst at IDC.

The Asia/Pacific market grew thanks in part to strong mobile phone shipments to Greater China, despite the seasonally slow quarter. In Japan, the market underperformed IDC's forecast as a result of the impact of the earthquake and tsunami.

In Western Europe, Android-based phones and iPhones helped grow the market in the seasonally slow quarter. New devices from HTC, Samsung and Sony Ericsson sold well in most countries in the high-end tiers.

Alcatel, Huawei, and ZTE Android devices helped drive mid-tier segment sales volume. The CEMA markets performed well on a year-over-year basis, despite civil unrest in some Gulf countries, such as Egypt. Nokia and Research In Motion performed well in the regions overall.

In the US last quarter, Apple's iPhone and the LTE-enabled HTC Thunderbolt were two smartphones introduced at Verizon Wireless that helped keep the category front and center of the overall mobile phone market, says the research firm. Feature phones continued to lose ground. Similarly, in Canada, the market grew thanks to smartphones. BlackBerry, iPhone, and Android devices were best sellers.

Latin America market growth continued last quarter. Smartphone shipments were aided by carriers who are moving customers to 3G networks, while vendors shipped more touchscreen and QWERTY models. New Android and Windows phone devices were launched too. The average selling prices also declined in the region, thanks to aggressive expansion by Chinese vendors.

Samsung, having posted a record first-quarter shipment volume, further closed the gap against market leader Nokia and extended its lead ahead of third place vendor LG Electronics. Samsung appears poised to reach its goal of 50 million smartphones shipped this year.

LG unit shipments declined on a year-over-year basis for the third straight quarter. The phone shipment drop off was most noticeable in Europe and the CIS countries, where shipments on a combined basis declined. The company hopes to deliver a better second quarter performance with the introduction of products such as the Revolution.

Apple maintained its number 4 spot on IDC's Top 5 list thanks to a record quarter for unit shipments. The company posted the highest growth rate of the worldwide leaders. Apple's results were buoyed by strong sales on Verizon Wireless and additional carrier deals; the company is now on 186 carriers operating in 90 countries. The iPhone once again sold particularly well in developed economic regions of the world, such as North America and Western Europe.

ZTE held on to the number 5 slot thanks to strong year-over-year growth in countries and regions where it does particularly well, such as China and Latin America.