BT Securities brokerage said in a statement that Silaghi sold 21.5 million shares in the bank, corresponding to a 2.0% stake, for 34.8 million lei ($11.9 million/8.2 million euro) and bought 3,972,500 shares, equal to a 0.4% stake, for 6.36 million lei on Tuesday.
Silaghi sold the 2.0% stake at an average price of 1.62 lei per share and bought the 0.4% stake at 1.6 lei per share.
Silaghi also sold a 1.23% stake in the bank two weeks ago. Data on Silaghi's ownership in Banca Transilvania following the transactions were not immediately available.
Nearly 26.5 million shares of Banca Transilvania changed hands for a combined 42.8 million lei in four transactions on the Bucharest Stock Exchange on Tuesday, bourse data showed. The number of shares corresponds to a combined stake of 2.49% in the bank.
Banca Transilvania shares traded down 0.63% at 1.59 by 1231 GMT on Wednesday.
The European Bank for Reconstruction and Development held a 14.98% stake in the bank as of June 30, data from Romania's Central Depository showed. Individuals owned 43.9% and companies held a combined 41.1% of Banca Transilvania.
(1 euro = 4.2473 Romanian lei)