In the Rosario grains market, soy closed at 1,820-1,850 pesos ($322-$327) per tonne, lower than 1,880 pesos on Tuesday. Local buyers were turned off by recent high prices, say traders.

Rosario soy for delivery in May 2014, which is quoted in US dollars, closed between $290 and $294 per tonne, from $290 on Tuesday.

In the Argentine port of Bahia Blanca, soy closed at 1,861 pesos, 11 pesos less on the day.

Industries and ports in Rosario were almost paralyzed on Wednesday due to a protest by workers demanding better labor conditions.