BUENOS AIRES, April 22 (Reuters) - Argentina's stock, currency and bond market trends on Wednesday:
* The MerVal stocks index .MERV rose 0.54 percent to 1,226.97 points, climbing for a second straight session due to solid gains by index heavyweight Tenaris.
* Tenaris TENA.BATS.N, which makes steel pipes for the energy industry and is weighted as almost half the MerVal, rose 2.04 percent to 45.1 pesos per share as investors bought the stock as a safe-haven from the peso's depreciation, traders said.
* On the broader market, trade volume was thin at just over $12 million. Of active issues 35 declined, 19 advanced and 8 were unchanged.
* Prices for government bonds traded over the counter in Buenos Aires also rose for a second consecutive day, gaining 0.6 percent on average in selective buying.
* Peso-denominated Par bonds ARPARP=RASL gained 1.7 percent, according to the ask price.
* In formal exchange between banks, the peso fell 0.14 percent to 3.695/3.6975 per dollar ARS=RASL, its fourth consecutive loss against the greenback. Traders said central bank dollar purchases exceeded sales by grains exporters.
* In informal trade between foreign exchange houses as measured by Reuters, the peso fell by 0.4 percent to 3.7375/3.7425 ARSB=. (Reporting by Walter Bianchi and Jorge Otaola; Writing by Helen Popper; Editing by Diane Craft)