(Reuters) - Google's Android smartphone software stretched its market lead in early 2012, helped by new models from handset makers like Samsung and HTC and piling the pressure on rivals like Research In Motion and Nokia.

Research from Kantar WorldPanel on Tuesday showed Android gaining share strongly in most of seven major markets - Australia, Britain, France, Germany, Italy, Spain and the United States - in the 12 weeks to mid April.

In Spain and Italy, its market share more than doubled year-on-year to 72 percent and 49 percent respectively, while it almost doubled to 62 percent in Germany.

Strong demand for the iPhone 4S helped market No.2 Apple narrow the gap with Android in the United States and Britain, but its share slipped in continental Europe.

Microsoft's Windows Phone began to show some signs of growth thanks to Nokia's decision to swap its legacy Symbian platform for Windows.

Windows' share in Germany more than doubled to 6 percent over the past year, and climbed to 3-4 percent in Britain, France, Italy and the United States.

These gains came at the expense of Nokia's Symbian platform and Canadian BlackBerry maker Research In Motion, the biggest market share losers. RIM's share in the U.S. market dropped to just 3 percent from 9 percent a year earlier.

Kantar said HTC's One X model made a strong start in Britain, making the Top 10 list for the 12 week period even though it was on sale for less than a week.