(Telecompaper) Samsung Electronics has seen sales of its Galaxy S4 smartphone exceed 10 million units globally. The milestone happened 20 days earlier than its predecessor, the Galaxy S3. The Galaxy S4 was launched on 27 April in some 60 countries and has since expanded to over 110 countries. Samsung plans to increase to this to 155 countries by the end of June. In addition to the two existing colours of white or black, it will introduce new models of the S4 this summer in blue, red, purple and brown.