Monbat erased 2.11% of its price on Thursday following a 3.26% gain on Wednesday.
Bulgarian Real Estate Fund REIT [BUL:5BU] was the top decliner with a 3.73% fall, while Advance Terrafund REIT [BUL:6A6] lost 1.15%.
The wider BGBX40 index, which tracks the 40 most traded shares on the Sofia bourse, slid 0.21% to 97.61 points, while the BGTR30 index, in which companies with a free float of at least 10% have equal weight, fell 0.23% to 484.92 points.
The BGREIT index, which tracks seven real estate investment trusts, dropped 1.73% to 133.20 points.
Total daily regulated market trading turnover amounted to 392,000 levs ($237,000/200,000 euro).
(1 euro = 1.95583 levs)