The strong sales of  iPhone 5 over the past 12 weeks has boosted iOS back to the number one spot in the US. It now has a 48.1% share of US smartphone sales compared with Android which has 46.7%, according to the latest smartphone sales data from Kantar Worldpanel ComTech.

Apple in September claimed that it  sold over five million of its new iPhone 5, just three days after its launch on September 21, and more than 100 million iOS devices have been updated with iOS 6, the world’s most advanced mobile operating system. iPhone 5 is available in the US, Australia, Canada, France, Germany, Hong Kong, Japan, Singapore and the UK, and will be available in 22 more countries on September 28 and more than 100 countries by the end of the year. Demand for iPhone 5 exceeded the initial supply and while the majority of pre-orders have been shipped to customers, many are scheduled to be shipped in October.

“Demand for iPhone 5 has been incredible and we are working hard to get an iPhone 5 into the hands of every customer who wants one as quickly as possible,” Tim Cook, Apple’s CEO has said . “While we have sold out of our initial supply, stores continue to receive iPhone 5 shipments regularly and customers can continue to order online and receive an estimated delivery date. We appreciate everyone’s patience and are working hard to build enough iPhone 5s for everyone.”

Dominic Sunnebo, global consumer insight director at Kantar Worldpanel ComTech, comments: “The last time we saw iOS overtake Android in the US was when the iPhone 4S was released and Apple managed to retain its lead for three consecutive periods. This time we predict that Apple will beat its previous high of 49.3% and achieve its highest ever share of the US smartphone market within the next two periods.”

The report says that Apple’s rise in the US has not been replicated in quite the same way across Europe where Android still takes the lead, accounting for 73.9% of sales in Germany and 81.7% in Spain. However, it is now enjoying share gains in four of the five major European countries with a particularly strong performance in Britain where it holds a 32.7% share.

Sunnebo continues: “Germany remains a tough market for Apple with its share falling by 5.1 percentage points over the past year. The Samsung Galaxy S3 has taken almost a quarter of the country’s smartphone sales over the past 12 weeks to boost Android yet further. In Italy, strong sales of the Nokia Lumia 610, the fourth best selling handset over the past 12 weeks, and the Nokia Lumia 800, the seventh best selling, have helped drive Windows’ share up to 11.7% – the highest across Europe.”

The majority of US iPhone 5 sales, 62%, have come from existing Apple owners upgrading to the new device, although Apple has also benefitted from people switching from Android devices (13%), people switching from BlackBerry devices (6%) and a small number of first time smartphone owners.

Sunnebo comments: “Apple has always managed to maintain loyalty levels far above the competition, and this has clearly played a part in driving sales of its new device. An impressive 92% of existing Apple owners in the US said they will choose an iPhone the next time they upgrade. While loyalty is clearly key, it is also important to make sure that new customers are attracted to your brand. With roughly 60% of US iPhone 5 sales coming from existing customers and 40% from new consumers, Apple is achieving this at the moment – a clear sign of the strength of the brand in the US marketplace.”

One of the key physical changes on the iPhone 5 was the inclusion of a bigger 4” screen and 4G/LTE capability, both of which appear to have had a big impact on the ways consumers are using their devices compared to previous models.

Sunnebo continues: “Previous KWP ComTech data has shown that bigger screens make a significant impact on the reality of how consumers actually use their device, and the latest usage data shows this is clearly the case for the iPhone 5. The usage data is likely to come down over time as iPhone 5 users at this stage will inevitably be early adopters and therefore more engaged with the category, but initial signs are very positive.”