NEW YORK: Customer loyalty levels to Apple's iPhone have declined for the first time since the product's launch in 2007, a multimarket survey has found.

Strategy Analytics, the insights group, revealed that 88% of US consumers owning these devices would probably buy another one when making their next category purchase.

Although this rating remained high, it constituted a slide from 93% in 2011, thus ending a trend which had seen repurchase intent rise consistently after the pioneering smartphone was released in 2007.

Totals on this metric also contracted in Western Europe, down from 88% last year to 75% at present, the survey found.

While the iPhone 5, introduced in September 2012, sold over 5m units in its first three days, Paul Brown, director of Strategy Analytics' user experience practice, said Apple faced a fresh challenge.

"There is no doubt that Apple is continuing its success in retaining existing user base while attracting new customers," he argued.

"However, negative press prompted by a perceived lack of recent innovation by Apple has meant we are starting to see some growth in the number of previously highly loyal consumers who are now reconsidering whether or not they will purchase a new iPhone for their next device."

More broadly, Brown reported that a poll of the smartphone audience conducted in late 2011 discovered that the largest number wanted such gadgets to have a 4.3-inch screen.

This figure had risen to 4.5 inches during the organisation's latest round of research, undertaken in the second half of 2012.

Apple's iPhone 5 still lags behind in this area, despite delivering an increase in display size to four inches from 3.5 inches as was the case for prior iterations of the device.

By contrast, Samsung's Galaxy SIII measures 4.8 inches, while HTC's One X and Motorola's RAZR HD come in at 4.7 inches apiece and Nokia's Lumia 920 measures 4.5 inches.

"On the back of a lack of recent innovation from Apple we are starting see growth in the number of previously highly loyal consumers who are considering whether or not they will purchase a new iPhone for their next device," he added.

Data sourced from Strategy Analytics; additional content by Warc staff