BUENOS AIRES, July 27 (Reuters) - Argentina's stock, currency and bond market trends on Monday:
* The MerVal stocks index .MERV rose 0.64 percent to 1,685.95 points on the strength of steel and energy stocks that were lifted by bargain-hunting in thin trade.
* Shares of steelmaker Siderar SID.BA, the local unit of Latin America's Ternium (TX.N) and the country's biggest producer of rolled steel, led the gains, rising 9.8 percent to 13.35 pesos per share.
* Prices for government bonds traded over-the-counter in Buenos Aires gained 1.5 percent on average.
* Bonds have been rising since last week, when the economy minister said he would seek to swap and buy back the inflation-indexed bonds that account for at least a third of the country's sovereign debt.
* The dollar-denominated 2014 Boden bond was among the winners, jumping 4 percent ARBODEN14D=RASL to an ask price of 20.90.
* On the broader market, volume was a thin $8.5 million. Among active issues, 41 advanced, 19 declined and 12 were unchanged.
* In formal trade between banks, the peso was unchanged at 3.8075/3.81 per dollar ARS=RASL as the central bank intervened in markets to keep the local currency stable.
* In informal trade between foreign exchange houses as measured by Reuters, the peso rose 0.26 percent to close at 3.87/3.875 per dollar ARSB=. Traders said interest in the greenback's safe-haven appeal had dipped and trade was light. (Reporting by Walter Bianchi; Writing by Dana Ford)