Research group iSupply reports that Apple's popular iPhone has sold more handsets than any other smartphone this July. The group also expects the device to come out on top of the feature phone category when the year ends.

The iPhone beat Research in Motion's popular Blackberry models and dominated models from rivals Nokia and Motorola in the smartphone category which encompasses models that have computer-like features.

Under the feature phone category where units with recreational extras such as cameras and mp3 players are classified, the iPhone equaled the sales of market leader Chocolate, manufactured by Korean consumer electronics giant LG.

The iPhone is considered by iSupply as a crossover between the two major mobile phone types due to the diversity of the features included in it.

The firm projects around 4.5 million units of iPhone sold by year's end and suggests that 20 million units could be in North American homes in four years.

Telecom giant AT&T saw a quarter of all iPhone users jump to its fold by virtue of its exclusive deal with Apple. Worldwide sales are expected to pick up even more when the iPhone hits Europe in the last quarter of the year.