(Telecompaper) MTN Group's revenue decreased by 18.5 percent to ZAR 64.315 billion in the first six months of 2017. Excluding currency effects, revenue rose 6.7 percent, underpinned by 10.8 percent growth in its largest market Nigeria and a 5.2 percent improvement in service revenue growth in South Africa. MTN Uganda, Ghana and Ivory Coast also contributed positively to the group's top-line growth. MTN Cameroon experienced a challenging period, negatively impacted by the data network shutdown in some parts of the country in the first quarter.