SOFIA (Bulgaria), August 4 (SeeNews) – Bulgarian telecommunications group BTC, operating under the Vivacom brand, said on Tuesday its adjusted earnings before interest, taxes, depreciation and amortization (EBITDA) decreased by 3.1% to 168.1 million levs ($94.4 million /85.9 million euro) in the first half of 2015 as net revenues jumped 3% to 405 million levs.