In the main grains market of Rosario, soy closed at 1,600-1,630 pesos ($311/$317) per tonne compared with Wednesday's 1,599 pesos, buoyed by gains in nearby US soy futures contracts.

Trade volume topped a healthy 25,000 tonnes compared with 12,000 tonnes in the prior session.

Soybean futures on the Chicago Board of Trade ended mixed on Thursday with nearby contracts gaining sharply against deferred months due to tight supplies of old-crop US soybeans, traders said.

In the southern grains port of Bahia Blanca, soy ended flat at 1,630 pesos per tonne. In Quequen, where no official price was listed for Wednesday, soy closed at 1,560 pesos.