BUENOS AIRES, Aug 8 (Reuters) - Argentine stocks slumped on Friday to their lowest level in more than 21 months, falling along with bonds for a second straight day as investors sold assets amid growing economic concerns.
Falling commodities prices also took a toll, traders said.
The benchmark MerVal index .MERV closed down 2.16 percent at 1,776.66 points, accumulating a 5.7 percent loss this week. It was the lowest close since Oct. 30, 2006.
"Once again the sell-off in bonds caused jitters in the stock market, which suffered sharp losses without any rational logic since quarterly earnings on the whole have grown 50 percent from last year," said Ruben Pascuali, a trader at Mayoral Bursatil brokerage.
"Many of these falls resulted from a drop in the price for soy and other commodities," he added.
Index heavyweight Tenaris TENA.BA, which makes steel tubes for the energy industry, led the MerVal's losses, shedding 5.66 percent to 85.00 pesos a share due to a sharp fall in U.S. crude oil futures.
Trade volume on the overall market was a moderate $34.9 million. Of active shares, 51 rose, 71 fell and 11 were unchanged.
Argentine sovereign debt shed about 3 percent on average in over-the-counter trade, with the peso-denominated 2033 Discount bond shedding 4 percent.
Argentina's debt spreads widened more than 40 basis points to 727 basis points over U.S. Treasuries in late trade on Friday, according to JPMorgan's Emerging Markets Bond Index Plus (EMBI+) 11EMJ .JPMEMBIPLUS.
The peso slumped against the dollar for the fourth straight session as investors sought refuge in safe-haven greenbacks and as the dollar firmed globally, traders said.
In formal interbank trade, where the central bank regularly intervenes to stabilize the local currency, the peso slipped 0.16 percent to 3.0500/3.0525 per dollar ARS=RASL.
In informal trade between foreign exchange houses, as measured by Reuters, the peso shed 0.41 percent to end at 3.0750/3.0775 per dollar ARSB=. (Reporting by Walter Bianchi; Writing by Hilary Burke; Editing by Dan Grebler)