BUENOS AIRES, April 20 (Reuters) - Argentina's stock, currency and bond market trends on Monday:
* The MerVal stocks index .MERV plunged 5.19 percent to 1,193.03 points, its biggest one-day fall since early March, mirroring losses in global stock markets hit by renewed concern over the health of the U.S. banking system.
* Tenaris TENA.BATS.N, which makes steel pipes for the energy industry and is weighted as almost half of the MerVal, sank 7.17 percent to 42.75 pesos per share.
* On the broader market, trade volume was light at $13.1 million. Of active issues 42 declined, 6 advanced and 13 were unchanged.
* Prices for government bonds traded over the counter in Buenos Aires slipped 2.1 percent on average, trimming their gains since the start of the month to 7.2 percent.
* Dollar-denominated Discount bonds ARDISCD=RASL shed 5.02 percent, according to the ask price.
* In formal exchange between banks, the peso slipped 0.2 percent to 3.6875/3.69 per dollar ARS=RASL, its second consecutive loss against the greenback. Traders said the central bank had sold some dollars in the session, but had not intervened heavily.
* In informal trade between foreign exchange houses as measured by Reuters, the peso gained 0.27 percent to 3.72/3.725 ARSB=. (Reporting by Walter Bianchi and Jorge Otaola; Writing by Helen Popper; Editing by Leslie Adler)