(Telecompaper) MTN Group reported a 4.9 percent decrease in revenues for the first half to ZAR 69.2 billion, hurt by negative currency effects. Despite the negative currency effects, the group continued to benefit from increased demand for data services, increasing data revenue by 21.3 percent. This followed an 87 percent annual increase in data traffic as well as encouraging growth in digital and mobile financial services, MTN said. EBITDA decreased 10.1 percent to ZAR 30.3 billion, and the EBITDA margin declined by 2.6 percentage points to 43.7 percent, mainly as a result of lower revenue and weaker local currencies impacting costs. The sale and lease back of towers, which were largely earnings neutral due to lower depreciation costs, were also a drag on the EBITDA margin. However, good progress in transforming the operating model, maintaining cost growth below inflation and optimising resources partly offset the decline in margin. Headline earnings decreased 10.3 percent to ZAR 6.54, in line with the mobile operator's earlier trading update. MTN said the results reflect a challenging operating environment and lower-than-expected performance in parts of the business.