Market research company Canalys has said that Google’s open source OS for smartphones Android leads in 35 countries across the world, with a global smartphone market share of 48%.

In its worldwide country-level Q2 2011 smart phone market estimates, Canalys tracked 56 countries, and said that substantial market growth continues in all regions.

Globally, the market grew 73% year-on-year, with in excess of 107.7 million units shipping in the second quarter of 2011.

Asia-Pacific (APAC) remained the largest regional market, with 39.8 million units shipping there, compared with 35.0 million in Europe, the Middle East and Africa (EMEA), and 32.9 million in the Americas.

Android, the number one platform by shipments since Q4 2010, was also the strongest growth driver this quarter, said Canalys, with Android-based smart phone shipments up 379% over a year ago to 51.9 million units.

Meanwhile, with shipments of 20.3 million iPhones and a market share of 19%, Apple’s iOS overtook Nokia’s Symbian platform during the quarter to take second place worldwide.

Apple also became the world’s leading individual smartphone vendor, stripping Nokia of its long-held leadership position, said Canalys. Samsung also moved ahead of Nokia.

Canalys VP and Principal Analyst Chris Jones said the iPhone has been a phenomenal success story for Apple and a watershed product for the market.

Jones said, "It’s an impressive success story, given that Apple has only been in the smart phone market for four years. With the next-generation iPhone anticipated in Q3, it’s likely that Apple’s position will grow even stronger in the second half of the year."

However, Nokia still leads in the BRIC countries: Brazil, Russia, India and China.

Canalys Principal Analyst Pete Cunningham said, "The problem for Nokia is that demand for its Symbian-based smart phones has dissipated very rapidly, particularly in operator-led markets, such as Western Europe, where it’s been strong in the past."

RIM had a challenging quarter in North America, with its market share slipping to 12%, down from 33% a year ago. But RIM’s global shipments grew 11% year on year, keeping it the number one vendor in Latin America with a 28% share, said Canalys.