In the Rosario grains market, soy closed at $340 a tonne,

down from around $354 on Friday, in line with the influential

Chicago market.

Soybean futures in Chicago closed lower after the U.S. Department of Agriculture (USDA) held its estimate for U.S. soybean production steady, disappointing investors who had expected a cut.

Argentina's developing soy crop is in a good condition, a forecaster said, but recent heavy rains in the country's key agricultural region have led to waterlogged fields and fears of damage if dry weather does not return soon.

The USDA cut its estimate for Argentina's soy crop in 2013/14 to 54 million tonnes from 54.5.

In Rosario, soy for May delivery closed at $290 a tonne, unchanged from Friday.