The blue-chip SOFIX index, which tracks the 15 most liquid shares on the Bulgarian Stock Exchange (BSE), added 0.96% to 326.91 points, after rising by 0.23% on Wednesday.
The broader BG40, which includes the 40 most traded shares, fell 0.43% to 121.59 points after losing 0.21% in the previous trading session.
Total turnover on the regulated market rose to 1.0 million levs ($659,000/511,000 euro) from 566,452 levs on Wednesday.
Four of the 10 SOFIX components which were traded on Thursday advanced, as many fell and two ended flat.
Real estate investment fund Advance Terrafund [BUL:6A6] was the top SOFIX gainer for a second session in a row, closing 4.0% higher at 2.9 levs as 14,701 shares changed hands.
Industrial group Chimimport [BUL:6C4] was the top blue-chip decliner, closing 2.36% lower at 0.70 levs in a volume of 17,426 shares.
The BG-REIT index, which tracks the performance of real estate investment trusts, ended 1.44% higher at 80.52 points after falling by 0.16% on Wednesday.
The BG TotalReturn30, in which companies with a free float of at least 10% have equal weight, rose 0.18% to 248.31 points, following a 0.21% decrease in the previous trading session.
The CGIX Corporate Governance index, which includes companies strictly applying corporate governance principles, ended 0.1% lower at 73.46 points. It fell 1.17% on Wednesday.
(1 euro = 1.95583 Bulgarian levs)