LONDON: After losing its top spot to iOS in the holiday quarter of 2014, Android has regained its position as the number one smartphone operating system in the US, but its market share has fallen sharply in the UK, a new study has revealed.

According to the latest smartphone sales data from Kantar Worldpanel ComTech, the consumer insights firm, Android achieved 51.9% market share in the US for the three months ending in January 2015.

This was built on good performances by vendors Samsung and LG, although Apple's iPhone 6 remained America's top-selling smartphone with Samsung's Galaxy S5 coming in second.

The Galaxy S5 was also the second best-selling smartphone in the UK with market share of 8%, just under half that of the iPhone 6 at 17.6%. But the UK stood out in Europe as the country where Android's market share has fallen the most.

It fell -7.7% in the UK compared with -4% in Germany and -0.6% in Italy, although there were modest gains in France (0.2%) and Spain (0.4%). Outside Europe, Android fell even more in Australia (-10.8%) and China (-8%).

Across the five largest economies in Western Europe, Android's share declined by 2.2 percentage points year-on-year while iOS rose by 3.2 percentage points.

Meanwhile, the data showed that Apple's iOS reached its highest ever share in urban China where the iPhone 6 alone took a market share of 9.5% in the three months ending in January.

Xiaomi remained the largest smartphone vendor in urban China but was only 2.2 percentage points ahead.

"Leading into Chinese New Year, Apple iPhone 6 and 6 Plus drove sales to an unprecedented high in urban China," said Carolina Milanesi, chief researcher at Kantar Worldpanel ComTech.

She explained that iOS's share of the smartphone market reached 25.4%, a 4.5 percentage point increase over the same period in 2014, and that Apple is gaining ground around the world.

"Across key global markets, Apple's momentum generally continued from last month," she said. "Although Android was able to slow down the decrease in share in some countries such as Germany, Spain and France where its sales had started to look like they were in free fall."

Data sourced from Kantar Worldpanel; additional content by Warc staff