A 46.5% jump in sales prompted smartphones to outsell feature phones globally for the first time, according to a Gartner study.

Assessing sales for the second quarter, the researcher estimated that smartphones accounted for 51.8% of mobile phone sales across the world. Sales of feature phones declined 21% to 210 million units.

See also: How to Make Free Ringtones in iTunes

The study doesn't break down regional penetration. A recent comScore report showed the smartphone penetration in the United States is 59%.

Meanwhile, Gartner found that Samsung still leads the market in unit sales, though Apple's sales grew more since 2Q 2012.

Android also remains the dominant mobile OS with a 79% share. In that respect, the U.S. is an outlier. ComScore estimates that Android claims just 52% of the U.S. smartphone market.

The increase in worldwide smartphone sales is good news for Apple, which is rumored to be readying a release of a lower-cost version of the iPhone, the iPhone 5C. Such a model, which may lack features like Siri, would presumably appeal to more cost-conscious consumers in developing countries.

Image: Roberto Schmidt/Getty Images