Bulgarian Stock Exchange indices started the week in red, largely due to drops in the share prices of diversified group Doverie United Holding and lender First Investment Bank (Fibank). Doverie United Holding shares erased 3.61% to 3.20 levs, as the price was set by a deal for just 20 shares.Fibank shares dropped 3.21% to 3.02 levs - their lowest close since December 2016. Investors are awaiting the results of a check of the lender performed by the European Central Bank, which are due to be published by the end of the month.The two companies led decliners among blue chips, with the benchmark SOFIX index closing 0.53% lower at 579.47 points. The BGBX40 index, which tracks the 40 most traded shares on the stock exchange in Sofia, lost 0.32% to 114.70 points, while the BGTR30, in which companies with a free float of at least 10% have equal weight, fell 0.22% to 508.37 points. The BGREIT index, which tracks real estate investment trusts, decreased 0.10% to 126.40 points.Total regulated market trading turnover amounted to 195,000 levs ($112,000/100,000 euro).