(Reuters) - Global sales of mobile phones fell 2 percent in January-March after ten straight quarters of growth, as Chinese buyers held back in anticipation of new models and economic uncertainties weighed on developed markets, research firm Gartner said.

The data, published on Wednesday, confirmed South Korea's Samsung became the world's largest cellphone maker in the quarter, ending Finnish group Nokia's 14-year reign after years of losing ground, particularly in smartphones.

"The economic environment is challenging in Western Europe and North America," Gartner analyst Anshul Gupta said.

Handset sales in China, the largest single cellphone market, dropped more than 6 percent from a year ago as consumers waited for new, more advanced models coming to the market this quarter or next, he said.

Gupta said Nokia was hurt the most by the slowdown in demand. Its overall market share shrank to 19.8 percent from 25.1 percent a year ago, while its smartphone share dropped to just 9 percent in the quarter.

"Most of the losses of Nokia in smartphones are picked up by Samsung and Apple," Gupta said.

Samsung saw its market share rise to 20.7 percent, while Apple - No. 3 in global cellphone sales volumes - saw its share more than double to 7.9 percent.

Gartner said the slow start to the year made it cautious about the rest of 2012, and it would lower its full-year cellphone market growth outlook by around 1 percent or some 20 million handsets.

Gartner is the only research firm publishing data on actual sales to consumers, while others focus on production statistics. The role of market data is increasing in the industry as several key cellphone vendors have stopped publishing their volume data.