The blue-chip SOFIX index, which tracks the 15 most liquid shares on the Bulgarian Stock Exchange (BSE), closed 1.88% lower at 519.91 points after rising 0.44% in the previous session.
The broader BGBX40, which tracks the 40 most traded shares, ended 1.38% down at 103.92 points after closing 2.05% lower on Wednesday.
Turnover on the regulated market increased to 2.1 million levs ($1.3 million/1.1 millioneuro) from 980,700 levs on Wednesday.
First Investment Bank [BUL:5F4] was the top SOFIX gainer, closing 1.41% higher at 2.739 levs as 6,695 shares changed hands.
Fertiliser producer Neochim [BUL:3NB] led the top blue-chip decliners, closing 10% lower at 36 levs in a volume of 279 shares.
The BG-REIT index, which tracks the performance of the real estate investment trusts, lost 0.18% to 96.50 points after closing 0.47% lower in the previous session.
The BG TotalReturn30 index, in which companies with a free float of at least 10% have equal weight, went down 1.71% to 405.28 points after closing 0.71% higher in the previous session.
(1 euro=1.95583 Bulgarian levs)