BUENOS AIRES, June 10 (Reuters) - Argentina's stock, bond and currency market trends on Wednesday.
* The MerVal stocks index .MERV gained 0.8 percent to 1,654.99 points, its second straight gain, lifted by energy-related shares as oil prices hit a seven-month high.
* Shares in Tenaris (TENA.BA), which makes steel pipes for the energy industry and is weighted as almost half of the MerVal, rose 0.8 percent to 60.3 pesos per share.
* On the broad stock market, volume was modest at $11.4 million. Of active issues, 36 advanced, 23 declined and 13 were unchanged.
* Prices for government bonds traded over-the-counter in Buenos Aires gained 1.5 percent on average -- their second consecutive rise.
* The 2014 Boden bond denominated in pesos <ARBODEN14=RASL jumped 5.6 percent, according to the ask price.
* Dollar-denominated Boden 2012 bonds ARBODEN12D=RASL gained 0.8 percent as the government formally launched an auction tied to the early payment of a coupon that comes due in August. Participants will have until Friday to submit bids on the discount they would be willing to accept in the deal. [ID:nN10354443]
* In formal exchange between banks, the peso ended unchanged for a second straight session at 3.7575/3.76 per dollar ARS=RASL. Traders said the central bank continued to sell dollars to bolster the local currency.
* In informal trade between foreign exchange houses, as measured by Reuters, the peso weakened 0.2 percent to 3.8125/3.8175 ARSB=. (Reporting by Walter Bianchi; Writing by Helen Popper; Editing by Dan Grebler)