In the main grains market of Rosario, soy closed at 1,630-1,670 pesos ($318-$326) per tonne, compared with 1,665 pesos on Tuesday. Upward pressure on the local market came from bullish Chicago trade.

Trade volume was a moderate 12,000 tonnes compared with 15,000 tonnes on Tuesday.

Chicago Board of Trade soybean futures were higher on positioning and bull-spreading ahead of the release of the US Department of Agriculture's (USDA) March plantings and quarterly stocks reports at 11 a.m. CDT (1600 GMT) on Thursday, traders said.

Rosario soy for delivery in May, which is quoted in US dollars, closed up $3 at $325 per tonne.

In the southern port of Bahia Blanca, the oilseed traded stable at 1,650 pesos per tonne.

<Center><b><i>Copyright Reuters, 2013</b></i><br></center>