BUENOS AIRES, June 18 (Reuters) - Argentina's stock, bond and currency market trends on Thursday.
* The MerVal stocks index .MERV fell for the fourth straight session, slipping 0.3 percent to 1,529.90 points in light trade as banking stocks suffered as investors ditched government debt, traders said.
* Shares in banking group Grupo Financiero Galicia GFG.BA shed 1.77 percent to 1.11 pesos per share, while Banco Macro fell BMA.BA(BMA.N) fell 1.39 percent to end at 5.67 pesos per share.
* On the broad stock market, volume was a meager $10 million. Of active issues, 26 advanced, 28 declined and 18 were unchanged.
* Prices for government bonds traded over-the-counter in Buenos Aires fell for a second day, losing 1.3 percent on average as investors continued to take profit after recent gains in the local debt market.
* Par bonds denominated in pesos ARPARP=RASL plunged 5.2 percent, according to the ask price.
* In formal exchange between banks, the peso ended unchanged for a second day at 3.7650/3.7675 per dollar ARS=RASL as the central bank sold dollars to meet typical safe-haven demand for greenbacks before a June 28 mid-term vote.
* In informal trade between foreign exchange houses, as measured by Reuters, the peso firmed 0.39 percent to 3.855/3.86 ARSB=. (Reporting by Jorge Otaola; Writing by Helen Popper; Editing by Jan Paschal)