Donev bought the shares through several deals concluded on the floor of the Bulgarian Stock Exchange (BSE), the pharmaceuticals manufacturer said in a bourse filing last week.
Donev has directly acquired a total of 776,500 shares in Sopharma, representing 0.58% interest, since the beginning of December.
At the end of September, Donev Investments Holding was Sopharma's largest shareholder with a 25.93% stake. Donev Investments Holding is controlled by Ognyan Donev.
As at 16:00 CET on Tuesday, shares in Sopharma traded flat at 3.18 levs on the Bulgarian Stock Exchange.
(1 euro = 1.95583 levs)