When the 3G iPhone goes on sale in the US and 19 other countries on Thursday, Apple and its network partners will be aiming to stamp their mark on the fast-expanding smartphone market with a device designed to appeal to both mass market consumers and corporate users.

Despite its technological and other limitations, the original 2G touchscreen-based iPhone, launched just over a year ago in the US market, was a success measured by sales volume. Almost 6m units were sold worldwide before supplies ran out in May, according to Apple.