By David Dolan JOHANNESBURG (Reuters) – South Africa’s Naspers Ltd named company newcomer Bob van Dijk as chief executive, looking to tap his expertise in e-commerce in line with a strategy that has already transformed it into an emerging markets force worth nearly $50 billion. The company said in a statement on Saturday that Chief Executive Koos Bekker would step down in April after 17 years of explosive growth that turned the Cape Town company into one of the world’s most valuable media and internet firms. Van Dijk’s appointment marks the rare promotion of an outsider to Naspers’ top job and underscores its growing emphasis on e-commerce platforms such as auction sites and classified ads, areas where he has substantial knowledge. “In view of our strong development focus on e-commerce, the board believes that Bob has the skills to lead us into the next phase of our growth,” Chairman Ton Vosloo said in a statement.