BUENOS AIRES, May 12 (Reuters) - Argentina's stock, currency and bond market trends on Tuesday.
* The MerVal stocks index .MERV rose for a ninth straight session, boosted by banking and energy shares, traders said.
* The index closed 0.86 percent higher at 1,525.22 points, accumulating a nearly 23 percent gain since April 29.
* Banco Macro (BMA.BA), one of Argentina's biggest private banks, jumped 8.4 percent to 6.21 pesos a share.
* Shares in index heavyweight Tenaris (TENA.BA), which makes steel tubes for the energy industry, gained 1.5 percent to end at 53.80 pesos.
* On the broad stock market, volume was moderate at $17.6 million. Of active issues 39 advanced, 34 declined and 10 were unchanged.
* Prices for government bonds traded over-the-counter in Buenos Aires fell 1.7 percent on average, sinking for a third straight session to accumulate losses of 4.5 percent.
* The dollar-denominated 2033 Discount bond ARDISCD=RASL plunged 6.5 percent to an ask price of 35.90.
* Bond purchases by government agencies and state-run banks have helped push values higher in recent weeks, with prices still up around 10 percent since May 1.
* In formal exchange between banks, where the central bank intervenes nearly every day, the Argentine peso closed flat at 3.7175/3.72 per dollar ARS=RASL.
* In informal trade between foreign exchange houses, as measured by Reuters, the peso shed 0.2 percent to 3.7525/3.7575 ARSB=. (Reporting by Walter Bianchi and Jorge Otaola; Writing by Hilary Burke; Editing by Leslie Adler)