Some 4.36 million shares of the fund were traded in a single block deal at 0.73 lei per share, bourse data indicated.
The parties to the deal were not disclosed.
In regular trading, SIF Muntenia was up 0.48% at 0.7325 lei by 1134 GMT on the Bucharest bourse on Wednesday.
(1 euro = 4.5003 Romanian lei)