Nuclearelectrica fell 12.92% to 8.36 lei (EUR1.882) a share, as investors who bought stock today were no longer entitled to its dividend of RON1.01 a share from last year profits.
In turn, OMV Petrom lost 5.01% on the day to RON0.4365 a share, while Romgaz dropped 5.06% to RON33.
The BET-C closed down 84.37 points, or 2.54% at 3,237.55, while the BET index declined 125.19 points, or 1.9% at 6,463.65.
BET-FI, which tracks Fondul Proprietatea (FP.RO) and the five regional investment funds SIFs, lost 93.60 points at 27,506.17.
The benchmark index BET-BK finished the session at 1,194.57, down 1.29% on the day, while the energy stocks tracker BET-NG declined 3.39% to 663.34.
The wider BET-XT closed down 1.6% at 580.88.
Overall trade value in Bucharest was RON23.82 million (EUR5.36 million), sharply down from RON149.8 million Tuesday. (EUR1=RON4.4415)