Sales of Samsung’s latest smartphone Galaxy S4 have surpassed 10 million units since its launch on April 27, 2013, with the company claiming that it sold at a rate of four units per second.

The Galaxy S4, which rivals Apple’s iPhone, is currently on sale in 60 countries, with further plans to expand sales to 327 carriers in 155 countries by June 2013.

According to the South Korean firm, sales of its Galaxy S III reached the 10-million mark 50 days after its launch in 2012, while the Galaxy S II took five months and the Galaxy S seven months to reach the milestone.

Incorporating a full HD Super AMOLED display on a five inch screen with 441ppi, S4 is equipped with a rear 13MP camera, in addition to a dual Camera function that allows simultaneous use of both front and rear cameras.

Additional features of the device include Air View and Air Gesture that allows executing effortless tasks, while it provides users with the latest information about their health and comfort using S Health.

Samsung is also planning to launch more colour variations of the device by summer 2013, including Red Aurora, followed by Purple Mirage and Brown Autumn, to meet consumer demands and preferences.

According to a study by the American Customer Satisfaction Index (ASCI) Apple’s iPhone has lost ground to Samsung and Motorola Mobility in the US.