Google's Android mobile operating system extended its dominance in smartphones in the US and other major markets in early 2013, according to a survey published on Monday.

Kantar Worldpanel ComTech said Android was used on 49.3 percent of smartphones sold in the US market in the first quarter, compared to 43.7 percent for Apple's iOS, the operating system for the iPhone.

Android has thus boosted its lead from a year ago, when was ahead of Apple by a margin of 47.9 to 44.6 percent.

In other major markets, Android was even more dominant -- with 93.5 percent of smartphones in Spain, 73.6 percent in Germany, 69.4 percent in China, and 63.3 percent in France.

Japan was the only country in the survey where Apple was in the lead, with a 49.2 percent market share to 45.8 percent for Android.

But the survey also showed gains in several countries for a relative outsider, Microsoft's Windows Phone, following the upgraded platform introduced in late 2012.

In the United States, Windows boosted its share to 5.6 percent from 3.7 percent a year ago, Kantar said. Windows grabbed 10.9 percent of smartphone sales in Italy, 7.2 percent in France and 7.0 percent in Britain.

"As iOS and Android continue to battle it out for top selling smartphone OS, we have seen Windows steadily grow over the past year and is now at its highest sales share figure so far," said Kantar analyst Mary-Ann Parlato.

"Windows' strength appears to be the ability to attract first time smartphone buyers, upgrading from a featurephone," she said, adding that this means prospects are positive for Windows, especially in the United States.

"With over half of the US market still owning a featurephone, it's likely that many will upgrade over the coming year, which will ultimately contribute to more growth for the Windows brand," Parlato said.