BUENOS AIRES, Aug 6(Reuters) - Argentina's stock, currency and bond market trends on Thursday.
* MerVal stocks index .MERV fell 1.63 percent to close at 1,776.93 points, as oil prices fell off a six-week high and dragged down energy-related stocks.
* Market heavyweight Tenaris TENA.BA, a global leader in steel products for the oil industry, fell 2.47 percent to close at 59.3 pesos per share.
* On the broad market stocks volume was high at $22 million. Of active issues 39 advanced, 39 declined and 14 were unchanged.
* Prices for government bonds traded over-the-counter in Buenos Aires fell 0.3 percent on average in a second day of profit-taking after prices jumped early in the week following a key $2.25 billion payment on bonds.
* The 2038 peso-denominated Par bond ARPARD=RASL fell 2.3 percent to end at an ask price of 28.15.
* In formal exchange between banks the peso weakened slightly by 0.7 percent to 3.8250/3.8275 per dollar ARS=RASL.
* In informal trade between foreign exchange houses, as measured by Reuters, the peso firmed 0.33 percent to end at 3.8400/3.8450 ARSB=. (Reporting by Jorge Otaola, writing by Luis Andres Henao; Editing by Leslie Adler)