BUENOS AIRES, April 17 (Reuters) - Argentina's stock, currency and bond market trends on Friday:

* The MerVal stocks index gained 0.29 percent to 1,258.47 points, accumulating an 8.2 percent rise this week.

* Tenaris (TENA.BA: Quote, Profile, Research), which makes steel pipes for the energy industry and is weighted as almost half of the MerVal, dipped 0.11 percent to 46.05 pesos per share.

* On the broader market, trading volume was thin at $12.8 million. Among active issues 31 advanced, 22 declined and 17 were unchanged.

* Prices for government bonds traded over the counter in Buenos Aires resumed their upward tick, rising 0.4 percent on average to accumulate a 10 percent gain since April 1.

* Dollar-denominated Bonar 2013 bonds ARBONAR13D=RASL jumped 1.8 percent, according to the ask price.

* In formal exchange between banks, the peso slipped 0.14 percent to 3.68/3.6825 per dollar ARS=RASL. Traders said the central bank, which intervenes almost daily in this market to avert abrupt moves, bought greenbacks to expand its foreign reserves.

* In informal trade between foreign exchange houses as measured by Reuters, the peso weakened 0.13 percent to 3.73/3.7350 ARSB=.