2 MIN. DE LECTURA
NEW YORK, Sept 12 (Reuters) - U.S.-listed shares of Brazilian companies were down sharply on Friday after an opinion poll showed Brazilian President Dilma Rousseff has narrowed the lead of her top challenger, Marina Silva, in a likely runoff race.
Brazilian markets had gained in recent weeks when other polls showed Silva eventually defeating Rousseff. The current administration has been criticized by investors for excessive intervention in the economy.
U.S.-listed shares of state-run oil company Petrobras , which some analysts say has deteriorated under a government policy that forces it to subsidize fuels in the domestic market, were down 8.1 percent, the third most-actively traded stock on the New York Stock Exchange.
Shares of Banco Bradesco were down 5.2 percent, while shares of Itau Unibanco were down 6 percent. Miner Vale's shares were down 1.5 percent.
The BNY Mellon index of Latin American ADRs was down 3 percent, outpacing losses on the bank's index of leading American depositary receipts, which was down 0.6 percent.
Index snapshot at 15:15 EDT:
* S&P 500 was falling 12.39 points, or 0.62 percent.
* Nasdaq Comp was losing 25.45 points, or 0.55 percent.
* Dow industrials was dropping 71.19 points, or 0.42 percent.
* Russell 2000 was falling 11.86 points, or 1.01 percent.
* S&P MidCap was dropping 13.82 points, or 0.96 percent.
* S&P SmallCap was losing 7.21 points, or 1.07 percent. (Editing by Nick Zieminski)