Smartphones using Google’s Android operating system (OS) had a second slow month in a row in December with US sales of 450,000 compared with iPhone sales of 3.2 million, according to digital metrics firm ComScore.
But even though Android OS numbers fell to 52.3% from its peak of 53.7% last November, it still has the largest share of the smartphone market.
According to the data, which does not count employer-provided phones, there were 67.7 million Android OS users in January 2013, compared with 49.2 million at the start of 2012, a gain of 18.5 million.
In the same period, Apple's iPhone grew from 29.9 million to 48.9 million, an increase of 19 million.
Analysts say that, while Apple has done well with its mobile devices, Google is benefiting from all areas of growth on the internet, including video, social, advertising and mobile.
Google has ousted Apple as a favourite among investors, mainly because of confidence in Google’s ability to capture advertising revenues.
Apple remains the world’s most valuable company, but Google’s shares are trading at 25 times profit, compared with a price-to-earnings ratio of less than 10 for Apple
Battle for third place
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While Android and iOS remain the market leaders, together accounting for 90.1% of the US market, BlackBerry and Windows Phone are still battling it out for third place.
BlackBerry still leads with 7.6 million handsets in use versus 4 million for Windows Phone.
In the past year, both have lost users. BlackBerry was down 7.8 million, while users of Windows Mobile or Windows Phone dropped by 500,000.
Apple is the largest smartphone supplier in the US with a 37.8% share of the market, followed by Samsung with a 21.4% share.
This means Samsung has 41% of the US Android market compared with its worldwide share of nearly 50%.
Third is HTC, with a 9.7% share of the market. Analysts say its position in the US reflects the struggles it has been having more broadly. On Wednesday, HTC announced that its revenues in February fell by 40% year-on-year.
Fourth is Google-owned Motorola with an 8.6% share, down from 10.0% three months earlier. Like HTC, Motorola's share has been falling steadily from March 2010, when it was the most-used brand in the US.
LG was the fifth-ranked smartphone brand, with 7.0%, equivalent to 9.1m users. That has risen from 8.1 million in October 2012.
But analysts said it is unclear whether the increase was due to sales of the LG-made Nexus 4 phone, which is branded as Google.