Net foreign investment in Romanian stocks tripled in the first half of this year, after the country joined the European Union in January.

Net foreign investment rose to 297 million euros ($404 million) from about 95 million euros in the same period last year, according to data published on the Bucharest Stock Exchange's Web site today.

The Bucharest exchange's benchmark BET index has gained about 19 percent this year. Romania joined the EU on Jan. 1, sparking a boom in foreign direct and portfolio investment.

Foreign investors bought 966 million euros of Romanian stocks in the first half, or 46 percent of all stocks bought in the period, and sold 669 million euros in stocks, data show.