The bourse operator, BSE, plans to buy up to 1,125,000 Capman shares at a price of up to 5.0576 levs apiece, the bourse operator said in a statement on Thursday.
BSE's shareholders will vote on the proposal at an extraordinary shareholders meeting scheduled for November 30.
According to commercial register data, private individual Nikolay Yalumov holds 91% of Sofia-based Capman.
As at 10:30 CET on Friday, shares in BSE traded 5.26% lower at a price of 9.00 levs.
(1 euro = 1.95583 levs)