The BVB said in a statement on its website (www.bvb.ro) it suspended trading as of 1108 a.m. local time (0808 GMT).
"All indices fell by more than 10% and the bourse halted trading to prevent them from falling further. I don’t think the bourse will restart trading today," one broker told SeeNews.
It was not immediately known when trading will resume.
BVB's blue-chip BET index has lost 9.25% to 3,600.96 points just before the BVB suspended trading, and the BET-FI index, which tracks Romania's five regional investment funds, the SIFs, sank 14.64% to 19,284.43 points.
The broker added that the bourse had suspended trading only once so far, in February 2005.
"Like today, there were heavy falls then and there were so many selling orders that the servers got blocked," he said.
The markets in Asia and Europe opened strongly in the red on Wednesday on concerns the credit crisis will deepen and will lead to global recession.
Stock markets in southeastern Europe have been losing ground in the past month, dragged down by panic selling on international markets following bank collapses in the U.S. and Europe.