The SOFIX index, which includes the 20 most liquid stocks on the Bulgarian Stock Exchange (BSE), slid 0.51% to 359.46 points, and the broader BG40 index, which tracks the 40 most traded shares on the bourse, lost 0.43% to 106.54.
"All stock indices climbed in early trade, lifted by optimism on most of the major global financial markets. But then ran out of steam and [the main indices] ended in negative territory," Sofia-based Bulbrokers said in a daily note.
BSE's total turnover, excluding block and other pre-agreed deals, increased to 4.4 million levs ($3.1 million/2.2 million euro) from 4.0 million levs on Friday.
Drug maker Sopharma was the most traded among the blue chips following news on Friday the it has launched a logistics centre, Bulbrokers said. The company ended at 2.25 levs, adding 2.27% in a volume of 51,946 shares.
Manufacturing companies like hydraulic equipment maker M+S Hydraulic and paints maker Orgachim outperformed, advancing 3.3% and 2.5%, respectively, in small volumes.
Industrial group Chimimport, in which 14,615, stocks changed hands, lost 1.9% to 2.06 levs.
Shares of mineral extracting and processing company Kaolin plunged 7.6% to 3.21 levs as 2,725 company stocks were traded.
On Monday, decliners outnumbered gainers 45 to 38 and 15 shares closed flat.
The BG TotalReturn30 (BG TR30) index, in which companies with a free float of at least 10% have equal weight, added 0.42% to 275.39 points, while the BG-REIT index, tracking the performance of real estate investment trusts, surged 4.17% to 47.51 points.
The Dnevnik 20 index, calculated by local business daily Dnevnik from the share prices of the 20 leading companies in terms of liquidity and market capitalisation, dropped 0.61% to 55.38 points.
(1 euro = 1.95583 Bulgarian levs)